Pub Date : 2025-11-01DOI: 10.1016/j.flatc.2025.100966
Rajapriya Govindaraju, Jongsung Kim
This study presents a UV-activated, nonenzymatic, and hydrogen peroxide–independent colorimetric sensing strategy for the highly sensitive and selective detection of dopamine (DA), utilizing MXene-derived quasi-quantum dots (MQQDs) as photoactive nanozymes. The MQQDs demonstrate pronounced UV-activated oxidase-mimetic catalytic activity, facilitating the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into its blue oxidized form (oxTMB) in the absence of H₂O₂. Upon the introduction of dopamine (DA), the absorbance intensity of oxTMB at 652 nm decreases progressively with increasing DA concentration. This attenuation is attributed to the redox interplay between DA and the photoexcited MQQDs, wherein DA acts as an electron donor, reducing oxTMB back to its colorless TMB form and thereby inhibiting the oxidation reaction. This electron-transfer-mediated inhibition mechanism enables quantitative colorimetric detection of DA with a detection limit of 65.4 nM. Spectroscopic analysis and kinetic fitting confirm the UV-triggered oxidase-mimetic behavior of MQQDs following Michaelis–Menten kinetics. The developed H₂O₂-free photoenzymatic platform offers a facile, stable, and environmentally benign route for DA quantification, with promising applicability in point-of-care diagnostics and neurochemical sensing.
{"title":"UV-induced, nonenzymatic, H₂O₂-free colorimetric detection of Dopamine using MXene-based quasi-quantum dots","authors":"Rajapriya Govindaraju, Jongsung Kim","doi":"10.1016/j.flatc.2025.100966","DOIUrl":"10.1016/j.flatc.2025.100966","url":null,"abstract":"<div><div>This study presents a UV-activated, nonenzymatic, and hydrogen peroxide–independent colorimetric sensing strategy for the highly sensitive and selective detection of dopamine (DA), utilizing MXene-derived quasi-quantum dots (MQQDs) as photoactive nanozymes. The MQQDs demonstrate pronounced UV-activated oxidase-mimetic catalytic activity, facilitating the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into its blue oxidized form (oxTMB) in the absence of H₂O₂. Upon the introduction of dopamine (DA), the absorbance intensity of oxTMB at 652 nm decreases progressively with increasing DA concentration. This attenuation is attributed to the redox interplay between DA and the photoexcited MQQDs, wherein DA acts as an electron donor, reducing oxTMB back to its colorless TMB form and thereby inhibiting the oxidation reaction. This electron-transfer-mediated inhibition mechanism enables quantitative colorimetric detection of DA with a detection limit of 65.4 nM. Spectroscopic analysis and kinetic fitting confirm the UV-triggered oxidase-mimetic behavior of MQQDs following Michaelis–Menten kinetics. The developed H₂O₂-free photoenzymatic platform offers a facile, stable, and environmentally benign route for DA quantification, with promising applicability in point-of-care diagnostics and neurochemical sensing.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100966"},"PeriodicalIF":6.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-01DOI: 10.1016/j.flatc.2025.100965
Chenxuan Xu , Junjie Yang , Wen Xu , Jie Fang , Nianhua Guan , Linjun Si , Weifeng Shen , Binbin Wen , Wanxin Mai , R. Chenna Krishna Reddy , Yongbo Wu , Xiaoming Lin
With the growth in the demand for sustainable energy, the development of efficient energy storage systems is of vital importance. Supercapacitors have attracted much attention due to their fast charging and discharging characteristics, but their performance is limited by the conductivity and stability of the electrode materials. This study proposes an environmentally friendly and scalable solid-phase synthesis strategy for in-situ preparation of NiS/V2O3/C heterogeneous nanostructures for high-performance supercapacitors. NiS/V2O3/C nanomaterials were obtained through vulcanization calcination by controlling the thermal annealing process. The construction of composite material heterojunctions can form an internal electric field, which greatly promotes charge transfer. Meanwhile, the high sulfur content and diverse valence states provide abundant redox active sites. Thanks to the unique synergistic effect and structure, the NiS/V2O3/C electrode exhibits excellent electrochemical performance in the 6 M KOH electrolyte: the specific capacity reaches 996 F g−1 at A current density of 1 A g−1, and the capacity retention rate after 3000 cycles was 76.2 %. This method provides a new idea for the large-scale preparation of polymetallic sulfide electrode materials and is expected to promote the development of high energy/power density energy storage devices.
随着可持续能源需求的增长，开发高效的储能系统至关重要。超级电容器因其快速充放电特性而备受关注，但其性能受到电极材料导电性和稳定性的限制。本研究提出了一种环境友好且可扩展的固相合成策略，用于原位制备高性能超级电容器用NiS/V2O3/C非均相纳米结构。通过控制热退火工艺，通过硫化煅烧制备了NiS/V2O3/C纳米材料。复合材料异质结的构建可以形成内部电场，极大地促进电荷的转移。同时，高含硫量和多种价态提供了丰富的氧化还原活性位点。由于独特的协同效应和结构，NiS/V2O3/C电极在6 M KOH电解液中表现出优异的电化学性能：在电流密度为1 A g−1时，比容量达到996 F g−1，循环3000次后容量保持率为76.2%。该方法为大规模制备多金属硫化物电极材料提供了新的思路，有望推动高能量/功率密度储能器件的发展。
{"title":"Structural design of MOF-derived NiS/V2O3/C heterogeneous nanostructures for high-performance supercapacitors","authors":"Chenxuan Xu , Junjie Yang , Wen Xu , Jie Fang , Nianhua Guan , Linjun Si , Weifeng Shen , Binbin Wen , Wanxin Mai , R. Chenna Krishna Reddy , Yongbo Wu , Xiaoming Lin","doi":"10.1016/j.flatc.2025.100965","DOIUrl":"10.1016/j.flatc.2025.100965","url":null,"abstract":"<div><div>With the growth in the demand for sustainable energy, the development of efficient energy storage systems is of vital importance. Supercapacitors have attracted much attention due to their fast charging and discharging characteristics, but their performance is limited by the conductivity and stability of the electrode materials. This study proposes an environmentally friendly and scalable solid-phase synthesis strategy for in-situ preparation of NiS/V<sub>2</sub>O<sub>3</sub>/C heterogeneous nanostructures for high-performance supercapacitors. NiS/V<sub>2</sub>O<sub>3</sub>/C nanomaterials were obtained through vulcanization calcination by controlling the thermal annealing process. The construction of composite material heterojunctions can form an internal electric field, which greatly promotes charge transfer. Meanwhile, the high sulfur content and diverse valence states provide abundant redox active sites. Thanks to the unique synergistic effect and structure, the NiS/V<sub>2</sub>O<sub>3</sub>/C electrode exhibits excellent electrochemical performance in the 6 M KOH electrolyte: the specific capacity reaches 996 F g<sup>−1</sup> at A current density of 1 A g<sup>−1</sup>, and the capacity retention rate after 3000 cycles was 76.2 %. This method provides a new idea for the large-scale preparation of polymetallic sulfide electrode materials and is expected to promote the development of high energy/power density energy storage devices.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100965"},"PeriodicalIF":6.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The advancement of multifunctional nanomaterials aimed at environmental remediation and energy storage presents a significant challenge in the field of sustainable modern technologies. This research work represents the synthesis of a novel and well interconnected ternary nanostructure of two-dimensional layered reduced graphene oxide (rGO) with bismuth (Bi) and nanorod-like vanadium oxide (V2O5) for methylene blue (MB) degradation and supercapacitor applications. The effective photocatalyst has been identified by preparing various arrays, adjusting the Bi content, and incorporating rGO with V2O5 system as Bi-V2O5 (BiV) and rGO-Bi-V2O5 (rGBiV) catalysts. The as-developed materials were successfully verified through various sophisticated structural and microstructural analyses. The morphological investigation demonstrated that rGO are in adherence with Bi and V2O5. The utilization of Bi and rGO with V2O5 resulted in decrease in the bandgap and enhanced charge separation. The rGBiV-1 composite demonstrated remarkable photocatalytic performance, attaining a 96.72 % degradation of MB within 90 min under visible-light irradiation. The •OH radical is shown to be essential in the photodegradation process. It is significant that •O2− radical also contributed to the improvement of photocatalytic activity. Electrochemical measurements demonstrated a notable improvement in capacitive behavior, with rGBiV-1 achieving a specific capacitance of 475 F g−1. This enhancement is linked to the synergistic effects of high surface area, effective electron transport through rGO, and the presence of redox-active sites (V5+/V4+). The findings demonstrate the promise of rGO-Bi-V2O5 nanohybrids as versatile materials for combined wastewater treatment and electrochemical energy storage applications.
以环境修复和能源储存为目标的多功能纳米材料的发展是可持续现代技术领域的一个重大挑战。这项研究工作代表了一种新型的、互连良好的二维层状还原氧化石墨烯（rGO）与铋（Bi）和纳米棒状氧化钒（V2O5）的三元纳米结构的合成，用于亚甲基蓝（MB）的降解和超级电容器的应用。通过制备各种阵列、调整Bi含量、将rGO与V2O5体系结合作为Bi-V2O5 （BiV）和rGO-Bi-V2O5 （rGBiV）催化剂，确定了有效的光催化剂。通过各种复杂的结构和微观结构分析，成功地验证了所开发的材料。形态学研究表明，氧化石墨烯与Bi和V2O5具有粘附性。Bi和rGO与V2O5的使用减小了带隙，增强了电荷分离。rGBiV-1复合材料表现出优异的光催化性能，在可见光照射下，90 min内对MB的降解率达到96.72%。•OH自由基在光降解过程中是必不可少的。值得注意的是，•O2−自由基也有助于提高光催化活性。电化学测量表明，rGBiV-1的电容性能得到了显著改善，比电容达到475 F g−1。这种增强与高表面积、通过氧化石墨烯的有效电子传递和氧化还原活性位点（V5+/V4+）的存在的协同效应有关。研究结果表明，rGO-Bi-V2O5纳米杂化材料有望成为污水联合处理和电化学储能应用的通用材料。
{"title":"Multicomponent nanostructured catalyst of rGO-Bi-V2O5 for photocatalytic degradation of methylene blue and supercapacitor applications","authors":"Sahil S. Magdum , Gowthami Palanisamy , Karuppaiah Selvakumar , Sadhasivam Thangarasu , Tae Hwan Oh","doi":"10.1016/j.flatc.2025.100962","DOIUrl":"10.1016/j.flatc.2025.100962","url":null,"abstract":"<div><div>The advancement of multifunctional nanomaterials aimed at environmental remediation and energy storage presents a significant challenge in the field of sustainable modern technologies. This research work represents the synthesis of a novel and well interconnected ternary nanostructure of two-dimensional layered reduced graphene oxide (rGO) with bismuth (Bi) and nanorod-like vanadium oxide (V<sub>2</sub>O<sub>5</sub>) for methylene blue (MB) degradation and supercapacitor applications. The effective photocatalyst has been identified by preparing various arrays, adjusting the Bi content, and incorporating rGO with V<sub>2</sub>O<sub>5</sub> system as Bi-V<sub>2</sub>O<sub>5</sub> (BiV) and rGO-Bi-V<sub>2</sub>O<sub>5</sub> (rGBiV) catalysts. The as-developed materials were successfully verified through various sophisticated structural and microstructural analyses. The morphological investigation demonstrated that rGO are in adherence with Bi and V<sub>2</sub>O<sub>5</sub>. The utilization of Bi and rGO with V<sub>2</sub>O<sub>5</sub> resulted in decrease in the bandgap and enhanced charge separation. The rGBiV-1 composite demonstrated remarkable photocatalytic performance, attaining a 96.72 % degradation of MB within 90 min under visible-light irradiation. The •OH radical is shown to be essential in the photodegradation process. It is significant that •O<sub>2</sub><sup>−</sup> radical also contributed to the improvement of photocatalytic activity. Electrochemical measurements demonstrated a notable improvement in capacitive behavior, with rGBiV-1 achieving a specific capacitance of 475 F g<sup>−1</sup>. This enhancement is linked to the synergistic effects of high surface area, effective electron transport through rGO, and the presence of redox-active sites (V<sup>5+</sup>/V<sup>4+</sup>). The findings demonstrate the promise of rGO-Bi-V<sub>2</sub>O<sub>5</sub> nanohybrids as versatile materials for combined wastewater treatment and electrochemical energy storage applications.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100962"},"PeriodicalIF":6.2,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-23DOI: 10.1016/j.flatc.2025.100964
Nuruzzaman Sakib , Md Rashidul Alam , Sara Neshani , Kasra Momeni
Two-dimensional transition metal dichalcogenides like tungsten diselenide (WSe₂) have exceptional electronic, optical, and thermal properties, which are critical for advanced device applications. However, understanding the impact of grain boundaries (GBs) on thermal conductivity remains limited. This study investigates the influence of tilt GBs on thermal transport in monolayer WSe₂ through non-equilibrium molecular dynamics simulations utilizing a reactive force field (ReaxFF). We systematically examined GBs with misorientation angles ranging from 1.12° to 21.79°, corresponding to pentagon-heptagon (5|7) defect densities from 0.00595 Å−1 to 0.11445 Å−1. Results show a significant reduction in thermal conductivity from 23.7 ± 0.96 W/mK for pristine WSe₂ to approximately 10.1 W/mK at the highest GB angle of 21.79°, highlighting enhanced phonon scattering. Additionally, Kapitza resistance notably increases from 0.31 m2K/GW at the lowest defect density (1.12°) to 5.08 m2K/GW at the highest defect density (21.79°), reflecting diminished heat transfer efficiency. This research underscores the critical role of GBs in modulating thermal transport in WSe₂ monolayers, providing valuable insights for thermal management in nanoscale electronic and thermoelectric devices, and paving the way for optimized device performance in next-generation flexible electronics.
{"title":"Thermal transport properties of WSe2 monolayer with tilt grain boundaries","authors":"Nuruzzaman Sakib , Md Rashidul Alam , Sara Neshani , Kasra Momeni","doi":"10.1016/j.flatc.2025.100964","DOIUrl":"10.1016/j.flatc.2025.100964","url":null,"abstract":"<div><div>Two-dimensional transition metal dichalcogenides like tungsten diselenide (WSe₂) have exceptional electronic, optical, and thermal properties, which are critical for advanced device applications. However, understanding the impact of grain boundaries (GBs) on thermal conductivity remains limited. This study investigates the influence of tilt GBs on thermal transport in monolayer WSe₂ through non-equilibrium molecular dynamics simulations utilizing a reactive force field (ReaxFF). We systematically examined GBs with misorientation angles ranging from 1.12° to 21.79°, corresponding to pentagon-heptagon (5|7) defect densities from 0.00595 Å<sup>−1</sup> to 0.11445 Å<sup>−1</sup>. Results show a significant reduction in thermal conductivity from 23.7 ± 0.96 W/mK for pristine WSe₂ to approximately 10.1 W/mK at the highest GB angle of 21.79°, highlighting enhanced phonon scattering. Additionally, Kapitza resistance notably increases from 0.31 m<sup>2</sup>K/GW at the lowest defect density (1.12°) to 5.08 m<sup>2</sup>K/GW at the highest defect density (21.79°), reflecting diminished heat transfer efficiency. This research underscores the critical role of GBs in modulating thermal transport in WSe₂ monolayers, providing valuable insights for thermal management in nanoscale electronic and thermoelectric devices, and paving the way for optimized device performance in next-generation flexible electronics.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100964"},"PeriodicalIF":6.2,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Horizontally aligned transition metal dichalcogenides (TMDCs) are well-suited for charge transport applications, while vertically oriented TMDCs are advantageous for high surface area applications such as catalysis, water splitting, and energy storage. However, the mechanism governing these structural and morphological transition remains unclear. This study provides a comprehensive growth time profile and demonstrates that parameters such as strain, distribution of grain boundaries, randomness and interlayer distance plays the critical role in driving the desirable morphological evolution. Here, we investigate the growth dynamics of MoSe₂ thin films synthesized via chemical vapor deposition (CVD), with a focus on understanding and optimizing the horizontal-to-vertical transition as a function of growth time. Scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM) were used to trace the stacking and structural order, while Raman spectroscopy and photoluminescence spectroscopy (PL) were used to investigate the variation of stacking and optical order. X-ray photoelectron spectroscopy (XPS) was used to investigate the chemical environment of the films, and field-effect transistors (FET) measurements were used to assess electrical properties such as mobility and surface carrier density. To support the experimental findings, a computational multilayer stacking framework was developed to project desirable randomness in a controlled manner through the variation of interlayer distance and simulating extent of strain mediation through wide range of unstrained, compressive, tensile and even highly diffusive strain states. This model helps to establish the relationship between the interlayer distortion and randomness with the optical asymmetry, providing insights into strain-mediated widely distributed direct to indirect optical transitions. This can further serve as an optical marker especially for these highly randomized directional vertical oriented flakes. Overall, this study presents a fundamental understanding of strain-induced morphological transitions in MoSe₂ thin films and offers a framework for tracing and tuning the optical and electronic properties in anisotropic 2D materials.
{"title":"Strain-mediated rapid growth of vertically oriented 2D MoSe₂: Insights into the growth mechanism","authors":"Rohit Kumar , Shreya Chandravanshi , Rejaul Ali , Subhashis Gangopadhyay , Arnab Hazra","doi":"10.1016/j.flatc.2025.100963","DOIUrl":"10.1016/j.flatc.2025.100963","url":null,"abstract":"<div><div>Horizontally aligned transition metal dichalcogenides (TMDCs) are well-suited for charge transport applications, while vertically oriented TMDCs are advantageous for high surface area applications such as catalysis, water splitting, and energy storage. However, the mechanism governing these structural and morphological transition remains unclear. This study provides a comprehensive growth time profile and demonstrates that parameters such as strain, distribution of grain boundaries, randomness and interlayer distance plays the critical role in driving the desirable morphological evolution. Here, we investigate the growth dynamics of MoSe₂ thin films synthesized via chemical vapor deposition (CVD), with a focus on understanding and optimizing the horizontal-to-vertical transition as a function of growth time. Scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM) were used to trace the stacking and structural order, while Raman spectroscopy and photoluminescence spectroscopy (PL) were used to investigate the variation of stacking and optical order. X-ray photoelectron spectroscopy (XPS) was used to investigate the chemical environment of the films, and field-effect transistors (FET) measurements were used to assess electrical properties such as mobility and surface carrier density. To support the experimental findings, a computational multilayer stacking framework was developed to project desirable randomness in a controlled manner through the variation of interlayer distance and simulating extent of strain mediation through wide range of unstrained, compressive, tensile and even highly diffusive strain states. This model helps to establish the relationship between the interlayer distortion and randomness with the optical asymmetry, providing insights into strain-mediated widely distributed direct to indirect optical transitions. This can further serve as an optical marker especially for these highly randomized directional vertical oriented flakes. Overall, this study presents a fundamental understanding of strain-induced morphological transitions in MoSe₂ thin films and offers a framework for tracing and tuning the optical and electronic properties in anisotropic 2D materials.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100963"},"PeriodicalIF":6.2,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-22DOI: 10.1016/j.flatc.2025.100957
Shulong Chen , Xijun Wang , Shengxing Wang , Huacheng Wu , Ruina Ma , An Du , Xue Zhao , Yongzhe Fan
The agglomeration of graphene in conventional silver composite plating baths significantly compromises coating homogeneity and performance. This study introduces γ-methacryloxypropyl trimethoxysilane (KH-570) as a silane coupling agent to functionalize graphene, enhancing its dispersion and interfacial adhesion with the silver matrix. Pure silve, unmodified graphene/silver (G/Ag), and KH-570-modified graphene/silver (MG/Ag) coatings were fabricated via brush plating under varying voltages (3 V, 4 V, 5 V). Systematic investigations revealed that the MG/Ag coating exhibited superior microstructural compactness, with 64% higher microhardness (HV 140) and 65% lower wear rate compared to pure Ag. Electrochemical tests in 3.5% NaCl demonstrated a one-order-of-magnitude reduction in corrosion current density (0.086 × 10−6 A/cm2) for the 4 V MG/Ag coating, alongside a hydrophobic surface (contact angle: 112°) and reduced contact resistance (0.58 μΩ). The optimized voltage of 4 V facilitated refined grain structures, minimized defects, and enhanced graphene dispersion through covalent SiOC bonding. These improvements stem from KH-570's dual role in preventing graphene agglomeration and strengthening the Ag-graphene interface. The MG/Ag coating demonstrates exceptional wear resistance, corrosion inhibition, and electrical stability, positioning it as a robust candidate for high-voltage disconnectors in harsh outdoor environments. The concentration of KH-570 used in this study is analytical reagent (AR). This work provides a scalable, eco-friendly strategy for advancing durable electrical contact materials.
石墨烯在传统银复合镀液中的团聚严重影响了镀层的均匀性和性能。本研究引入γ-甲基丙烯氧基丙基三甲氧基硅烷（KH-570）作为硅烷偶联剂对石墨烯进行功能化，增强其与银基体的分散性和界面附着力。在不同电压（3 V、4 V、5 V）下，通过电刷镀制备了纯银、未改性石墨烯/银（G/Ag）和kh -570改性石墨烯/银（MG/Ag）涂层。系统研究表明，MG/Ag涂层具有优异的显微组织致密性，显微硬度（hv140）比纯Ag涂层高64%，磨损率降低65%。在3.5% NaCl中进行的电化学测试表明，4 V MG/Ag涂层的腐蚀电流密度降低了一个数量级（0.086 × 10−6 a /cm2），同时具有疏水表面（接触角为112°）和降低的接触电阻（0.58 μΩ）。优化后的电压为4v有助于细化晶粒结构，减少缺陷，并通过共价SiOC键增强石墨烯的分散性。这些改进源于KH-570在防止石墨烯团聚和强化ag -石墨烯界面方面的双重作用。MG/Ag涂层具有优异的耐磨性、缓蚀性和电气稳定性，使其成为恶劣室外环境下高压隔离器的可靠候选者。本研究使用的KH-570浓度为分析试剂（AR）。这项工作为推进耐用的电接触材料提供了一种可扩展的、环保的策略。
{"title":"KH-570 Silane modification for enhanced graphene/silver nanocomposite brush plating: Process optimization and Tribo-corrosion properties","authors":"Shulong Chen , Xijun Wang , Shengxing Wang , Huacheng Wu , Ruina Ma , An Du , Xue Zhao , Yongzhe Fan","doi":"10.1016/j.flatc.2025.100957","DOIUrl":"10.1016/j.flatc.2025.100957","url":null,"abstract":"<div><div>The agglomeration of graphene in conventional silver composite plating baths significantly compromises coating homogeneity and performance. This study introduces γ-methacryloxypropyl trimethoxysilane (KH-570) as a silane coupling agent to functionalize graphene, enhancing its dispersion and interfacial adhesion with the silver matrix. Pure silve, unmodified graphene/silver (G/Ag), and KH-570-modified graphene/silver (MG/Ag) coatings were fabricated via brush plating under varying voltages (3 V, 4 V, 5 V). Systematic investigations revealed that the MG/Ag coating exhibited superior microstructural compactness, with 64% higher microhardness (HV 140) and 65% lower wear rate compared to pure Ag. Electrochemical tests in 3.5% NaCl demonstrated a one-order-of-magnitude reduction in corrosion current density (0.086 × 10<sup>−6</sup> A/cm<sup>2</sup>) for the 4 V MG/Ag coating, alongside a hydrophobic surface (contact angle: 112°) and reduced contact resistance (0.58 μΩ). The optimized voltage of 4 V facilitated refined grain structures, minimized defects, and enhanced graphene dispersion through covalent Si<img>O<img>C bonding. These improvements stem from KH-570's dual role in preventing graphene agglomeration and strengthening the Ag-graphene interface. The MG/Ag coating demonstrates exceptional wear resistance, corrosion inhibition, and electrical stability, positioning it as a robust candidate for high-voltage disconnectors in harsh outdoor environments. The concentration of KH-570 used in this study is analytical reagent (AR). This work provides a scalable, eco-friendly strategy for advancing durable electrical contact materials.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100957"},"PeriodicalIF":6.2,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1016/j.flatc.2025.100959
Edgar H. Ramírez-Soria , Marcelo A. Martínez-Puente , Armando E. Castillo , L.E. Elizalde-Herrera , M.A. Garza-Navarro , Tania E. Lara-Ceniceros , Alfredo Aguilar-Elguezabal , José Bonilla-Cruz
Graphene nanoplatelets possess exceptional physical and chemical properties; however, the absence of efficient large-scale production methods and their poor dispersion in solvents significantly hinder their practical applications. Chemical exfoliation enables the large-scale production of graphene nanoplatelets; nonetheless, these processes involve strong acids, potent oxidizing agents, and hazardous chemicals, raising environmental and scalability concerns. In this study, we propose an environmentally friendly, scalable, and sustainable one-pot approach for the large-scale production of phosphate-functionalized graphene nanoplatelets (G-POH) via anodic exfoliation at a rate of 3.5 g/(h·L). Key innovations include temperature control (25 °C), continuous extraction of exfoliated-functionalized nanoplatelets using a peristaltic pump, and electrolyte recirculation. Using a 1 M H₃PO₄ aqueous solution as both the electrolyte and the source of phosphate functional groups, we successfully obtained G-POH with a thickness of 3.6 ± 0.22 nm (∼2–3 layers per stack), and a specific surface area of 175 m2/g (BET). 31P NMR confirmed the presence of phosphate monoester species chemically bound to graphene nanoplatelets. Moreover, G-POH exhibited good dispersion in polar solvents, enabling the formulation of an aqueous-based conductive ink. This ink was effectively applied to various surfaces (cotton lab coats, ceramic tiles, glass, drywall, biaxially oriented polypropylene (BOPP), and polyester films), using multiple application methods (fountain pen, brush, and film coater). The resulting conductive patterns successfully illuminated multiple LEDs. The conductive film on a flexible BOPP substrate demonstrated excellent electrical conductivity (1.183 × 104 S/m, 16 ± 1.4 Ω/sq) over 100 bending cycles, highlighting its potential for flexible electronics and sustainable conductive coatings.
{"title":"Mass production of functionalized graphene nanoplatelets and their application as aqueous-based conductive inks","authors":"Edgar H. Ramírez-Soria , Marcelo A. Martínez-Puente , Armando E. Castillo , L.E. Elizalde-Herrera , M.A. Garza-Navarro , Tania E. Lara-Ceniceros , Alfredo Aguilar-Elguezabal , José Bonilla-Cruz","doi":"10.1016/j.flatc.2025.100959","DOIUrl":"10.1016/j.flatc.2025.100959","url":null,"abstract":"<div><div>Graphene nanoplatelets possess exceptional physical and chemical properties; however, the absence of efficient large-scale production methods and their poor dispersion in solvents significantly hinder their practical applications. Chemical exfoliation enables the large-scale production of graphene nanoplatelets; nonetheless, these processes involve strong acids, potent oxidizing agents, and hazardous chemicals, raising environmental and scalability concerns. In this study, we propose an environmentally friendly, scalable, and sustainable one-pot approach for the large-scale production of phosphate-functionalized graphene nanoplatelets (G-POH) via anodic exfoliation at a rate of 3.5 g/(h·L). Key innovations include temperature control (25 °C), continuous extraction of exfoliated-functionalized nanoplatelets using a peristaltic pump, and electrolyte recirculation. Using a 1 M H₃PO₄ aqueous solution as both the electrolyte and the source of phosphate functional groups, we successfully obtained G-POH with a thickness of 3.6 ± 0.22 nm (∼2–3 layers per stack), and a specific surface area of 175 m<sup>2</sup>/g (BET). <sup>31</sup>P NMR confirmed the presence of phosphate monoester species chemically bound to graphene nanoplatelets. Moreover, G-POH exhibited good dispersion in polar solvents, enabling the formulation of an aqueous-based conductive ink. This ink was effectively applied to various surfaces (cotton lab coats, ceramic tiles, glass, drywall, biaxially oriented polypropylene (BOPP), and polyester films), using multiple application methods (fountain pen, brush, and film coater). The resulting conductive patterns successfully illuminated multiple LEDs. The conductive film on a flexible BOPP substrate demonstrated excellent electrical conductivity (1.183 × 10<sup>4</sup> S/m, 16 ± 1.4 Ω/sq) over 100 bending cycles, highlighting its potential for flexible electronics and sustainable conductive coatings.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100959"},"PeriodicalIF":6.2,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-19DOI: 10.1016/j.flatc.2025.100960
Valentina Sierra-Jimenez , Farid Chejne , Manuel Garcia-Perez
This study integrates density functional theory and neural network algorithms to predict the spectra of 32 representative molecular structures identified in biochar. This approach addresses computational challenges in biochar molecular modeling and results in the generation of a spectral database covering X-ray photoelectron spectroscopy (XPS) (C 1 s, O 1 s, and N 1 s), Raman and infrared (IR) spectroscopy, 1H and 13C nuclear magnetic resonance (NMR), and 2D NMR. The spectra of independent molecules were then aggregated to describe the spectrum of cellulose char produced at 500 °C. Integrating first-principles predictions with machine-learning techniques establishes a connection between the atomic structures of biochar and their corresponding spectroscopic signatures. This work also expands the reliability of experimental data interpretation, providing a robust framework for atomic-level modeling and characterization. The theoretical spectra strongly aligned with experimental data, achieving >90 % agreement for 13C NMR and XPS and > 77 % correspondence for IR and Raman spectroscopy. These results demonstrate the enhanced predictive power of theoretical spectra derived from accurate molecular structures. The spectral database and atomistic structures lay the foundation for future research, providing opportunities to develop machine-learning algorithms that can effectively predict theoretical spectra. Furthermore, this approach facilitates the generation of spectra that would otherwise be costly or difficult to obtain experimental.
{"title":"First principles and neural network-driven biochar spectral database: Raman, XPS, IR, and NMR","authors":"Valentina Sierra-Jimenez , Farid Chejne , Manuel Garcia-Perez","doi":"10.1016/j.flatc.2025.100960","DOIUrl":"10.1016/j.flatc.2025.100960","url":null,"abstract":"<div><div>This study integrates density functional theory and neural network algorithms to predict the spectra of 32 representative molecular structures identified in biochar. This approach addresses computational challenges in biochar molecular modeling and results in the generation of a spectral database covering X-ray photoelectron spectroscopy (XPS) (C 1 s, O 1 s, and N 1 s), Raman and infrared (IR) spectroscopy, <sup>1</sup>H and <sup>13</sup>C nuclear magnetic resonance (NMR), and 2D NMR. The spectra of independent molecules were then aggregated to describe the spectrum of cellulose char produced at 500 °C. Integrating first-principles predictions with machine-learning techniques establishes a connection between the atomic structures of biochar and their corresponding spectroscopic signatures. This work also expands the reliability of experimental data interpretation, providing a robust framework for atomic-level modeling and characterization. The theoretical spectra strongly aligned with experimental data, achieving >90 % agreement for <sup>13</sup>C NMR and XPS and > 77 % correspondence for IR and Raman spectroscopy. These results demonstrate the enhanced predictive power of theoretical spectra derived from accurate molecular structures. The spectral database and atomistic structures lay the foundation for future research, providing opportunities to develop machine-learning algorithms that can effectively predict theoretical spectra. Furthermore, this approach facilitates the generation of spectra that would otherwise be costly or difficult to obtain experimental.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100960"},"PeriodicalIF":6.2,"publicationDate":"2025-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-15DOI: 10.1016/j.flatc.2025.100955
Rachel Rui Xia Lim , Alessandro Carvani , Adriano Ambrosi , Richard D. Webster , Alessandra Bonanni
Accurate detection, scaled-up testing and on-site monitoring are key attributes in effective and efficient management of pandemic outbreaks. In response to the urgent need for rapid and reliable detection of viral infections, this study investigates the use of graphdiyne—a novel two-dimensional carbon allotrope—as a platform for label-free electrochemical biosensing.
The RNA-dependent RNA polymerase (RdRp) fragment, immobilized on the graphdiyne surface, served as the probe for capturing the target gene specific to SARS-CoV-2. This biorecognition event was subsequently detected through electrochemical impedance spectroscopy.
The graphdiyne material demonstrated a strong adsorption ability with DNA molecules, which enabled a high selectivity in distinguishing the target sequence from mutant and non-complementary sequences, making the resulting genosensor applicable even when the detected virus undergoes mutations over time. A limit of detection in the nanomolar range was achieved, with a linear dynamic range of the response between 10−9 M to 10−5 M.
Coupled with the disposable printed electrodes that are portable and miniaturized sensing platforms, our developed approach can enable label-free detection to be mass-performed outside of routine laboratories.
{"title":"Graphdiyne-enhanced impedimetric detection of virus-induced infections","authors":"Rachel Rui Xia Lim , Alessandro Carvani , Adriano Ambrosi , Richard D. Webster , Alessandra Bonanni","doi":"10.1016/j.flatc.2025.100955","DOIUrl":"10.1016/j.flatc.2025.100955","url":null,"abstract":"<div><div>Accurate detection, scaled-up testing and on-site monitoring are key attributes in effective and efficient management of pandemic outbreaks. In response to the urgent need for rapid and reliable detection of viral infections, this study investigates the use of graphdiyne—a novel two-dimensional carbon allotrope—as a platform for label-free electrochemical biosensing.</div><div>The RNA-dependent RNA polymerase (RdRp) fragment, immobilized on the graphdiyne surface, served as the probe for capturing the target gene specific to SARS-CoV-2. This biorecognition event was subsequently detected through electrochemical impedance spectroscopy.</div><div>The graphdiyne material demonstrated a strong adsorption ability with DNA molecules, which enabled a high selectivity in distinguishing the target sequence from mutant and non-complementary sequences, making the resulting genosensor applicable even when the detected virus undergoes mutations over time. A limit of detection in the nanomolar range was achieved, with a linear dynamic range of the response between 10<sup>−9</sup> M to 10<sup>−5</sup> M.</div><div>Coupled with the disposable printed electrodes that are portable and miniaturized sensing platforms, our developed approach can enable label-free detection to be mass-performed outside of routine laboratories.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100955"},"PeriodicalIF":6.2,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-14DOI: 10.1016/j.flatc.2025.100953
Zhenli Hao , Jiaxiang Du , Zhao Wang , Long Lin , Shunwei Xu
Developing gas sensors that possess both high sensitivity and excellent selectivity remains a challenge. Employing first-principles computational methods, our research systematically explored the adsorption performance and gas sensing mechanism of Nb, Mo, and Sn doped PdSe2 monolayer films against SO2, CO, NO2, H2S, NH3. The doping results show that the doping of Mo and Nb significantly reduces the band gap to 0.66 eV, introduces impurity states near the Fermi level, enhances conductivity and forms chemical adsorption. Among them, Mo-PdSe2 had the strongest adsorption of SO2 and Nb-PdSe2 had the best adsorption of NO2, and there were obvious electron cloud overlap and orbital hybridization between them and gas molecules. Sn doping only slightly increased the adsorption energy, but it was still dominated by physical adsorption, and the adsorption capacity of NO2 decreased. The recovery time calculation shows that Sn-PdSe2 recovers faster for all kinds of gases, while the Mo/Nb doped system responds better to specific gases. This study provides a theoretical basis for the design of high-performance PdSe2-based gas-sensing devices, and reveals that doped transition metals can effectively adjust their adsorption selectivity and electronic properties.
{"title":"The adsorption behavior of toxic gases on transition metal (Mo, Nb, Sn) doped PdSe2 monolayer: A theory study","authors":"Zhenli Hao , Jiaxiang Du , Zhao Wang , Long Lin , Shunwei Xu","doi":"10.1016/j.flatc.2025.100953","DOIUrl":"10.1016/j.flatc.2025.100953","url":null,"abstract":"<div><div>Developing gas sensors that possess both high sensitivity and excellent selectivity remains a challenge. Employing first-principles computational methods, our research systematically explored the adsorption performance and gas sensing mechanism of Nb, Mo, and Sn doped PdSe<sub>2</sub> monolayer films against SO<sub>2</sub>, CO, NO<sub>2</sub>, H<sub>2</sub>S, NH<sub>3</sub>. The doping results show that the doping of Mo and Nb significantly reduces the band gap to 0.66 eV, introduces impurity states near the Fermi level, enhances conductivity and forms chemical adsorption. Among them, Mo-PdSe<sub>2</sub> had the strongest adsorption of SO<sub>2</sub> and Nb-PdSe<sub>2</sub> had the best adsorption of NO<sub>2</sub>, and there were obvious electron cloud overlap and orbital hybridization between them and gas molecules. Sn doping only slightly increased the adsorption energy, but it was still dominated by physical adsorption, and the adsorption capacity of NO<sub>2</sub> decreased. The recovery time calculation shows that Sn-PdSe<sub>2</sub> recovers faster for all kinds of gases, while the Mo/Nb doped system responds better to specific gases. This study provides a theoretical basis for the design of high-performance PdSe<sub>2</sub>-based gas-sensing devices, and reveals that doped transition metals can effectively adjust their adsorption selectivity and electronic properties.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100953"},"PeriodicalIF":6.2,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号