The effect of varying etchant on the synthesis of early 1st-row transition metal-based MXenes, including titanium (Ti), vanadium (V), and chromium (Cr), from their corresponding MAX phases were explored for supercapacitor applications. The MXenes were synthesised via chemical etching using HF/HCl or NaF/HCl mixtures, revealing that HF favors Ti-MXene while NaF is more effective for V- and Cr-MXenes. Comprehensive physiochemical characterisation including XRD, FTIR and XPS analyses confirmed the successful formation of transition metal carbides. FE-SEM/EDS and HR-TEM analyses revealed a two-dimensional layered morphology in each MXene with distinct lattice fringes, exhibiting d-spacing values of 0.245 nm, 1.556 nm, and 0.549 nm for Ti3C2Tx, V2CTx, and Cr2CTx respectively, confirming their crystalline nature. Furthermore, cyclic voltammetry revealed that V2CTx delivered the highest specific capacitance at 408.26 F g−1, compared to Ti3C2Tx (97.23 F g−1) and Cr2CTx (72.92 F g−1) at 2 mV s−1. Similarly, galvanostatic charge-discharge measurements showed a capacitance of 625.00 F g−1 for V2CTx, significantly outperforming Ti3C2Tx (191.44 F g−1) and Cr2CTx (41.19 F g−1) at 0.5 A g−1, while electrochemical impedance spectroscopy further confirmed its higher conductivity than the other MXenes. These findings underscore the critical role of the etchant in MXene synthesis and demonstrate the superior electrochemical performance of V-MXenes for supercapacitor electrodes.
研究了不同蚀刻剂对钛（Ti）、钒(V)和铬（Cr）等第一行过渡金属基MXenes的影响，探讨了其在超级电容器中的应用。用HF/HCl或NaF/HCl混合物进行化学刻蚀合成MXenes，发现HF有利于ti -MXenes， NaF对V-和Cr-MXenes更有效。包括XRD、FTIR和XPS分析在内的综合理化表征证实了过渡金属碳化物的成功形成。FE-SEM/EDS和HR-TEM分析显示，Ti3C2Tx、V2CTx和Cr2CTx的d-spacing分别为0.245 nm、1.556 nm和0.549 nm，各MXene均呈二维层状，具有明显的晶格条纹，证实了它们的结晶性质。此外，循环伏安法表明，在2mv s−1下，V2CTx的比电容最高，为408.26 F g−1，而Ti3C2Tx为97.23 F g−1，Cr2CTx为72.92 F g−1。同样，恒流充放电测量表明，V2CTx的电容为625.00 F g−1，显著优于Ti3C2Tx （191.44 F g−1）和Cr2CTx (41.19 F g−1)，而电化学阻抗谱进一步证实了其电导率高于其他MXenes。这些发现强调了蚀刻剂在MXene合成中的关键作用，并证明了v -MXene用于超级电容器电极的优越电化学性能。
{"title":"Role of transition metal and etchant in the synthesis of MXenes (Ti-, V-, and Cr-) and their electrochemical properties as supercapacitor electrodes","authors":"Syeda Sheeza Nadeem , Rizwan Khan , Afiten Rahmin Sanjaya , Muhammad Iqbal Syauqi , Yulia Mariana Tesa Ayudia Putri , Respati Kevin Pramadewandaru , Ferry Anggoro Ardy Nugroho , Munawar Khalil , Tribidasari Anggraningrum Ivandini","doi":"10.1016/j.flatc.2025.100944","DOIUrl":"10.1016/j.flatc.2025.100944","url":null,"abstract":"<div><div>The effect of varying etchant on the synthesis of early 1st-row transition metal-based MXenes, including titanium (Ti), vanadium (V), and chromium (Cr), from their corresponding MAX phases were explored for supercapacitor applications. The MXenes were synthesised via chemical etching using HF/HCl or NaF/HCl mixtures, revealing that HF favors Ti-MXene while NaF is more effective for V- and Cr-MXenes. Comprehensive physiochemical characterisation including XRD, FTIR and XPS analyses confirmed the successful formation of transition metal carbides. FE-SEM/EDS and HR-TEM analyses revealed a two-dimensional layered morphology in each MXene with distinct lattice fringes, exhibiting d-spacing values of 0.245 nm, 1.556 nm, and 0.549 nm for Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>, V<sub>2</sub>CT<sub>x</sub>, and Cr<sub>2</sub>CT<sub>x</sub> respectively, confirming their crystalline nature. Furthermore, cyclic voltammetry revealed that V<sub>2</sub>CT<sub>x</sub> delivered the highest specific capacitance at 408.26 F g<sup>−1</sup>, compared to Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> (97.23 F g<sup>−1</sup>) and Cr<sub>2</sub>CT<sub>x</sub> (72.92 F g<sup>−1</sup>) at 2 mV s<sup>−1</sup>. Similarly, galvanostatic charge-discharge measurements showed a capacitance of 625.00 F g<sup>−1</sup> for V<sub>2</sub>CT<sub>x</sub>, significantly outperforming Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> (191.44 F g<sup>−1</sup>) and Cr<sub>2</sub>CT<sub>x</sub> (41.19 F g<sup>−1</sup>) at 0.5 A g<sup>−1</sup>, while electrochemical impedance spectroscopy further confirmed its higher conductivity than the other MXenes. These findings underscore the critical role of the etchant in MXene synthesis and demonstrate the superior electrochemical performance of V-MXenes for supercapacitor electrodes.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100944"},"PeriodicalIF":6.2,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217255","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 : 2025-09-22DOI: 10.1016/j.flatc.2025.100943
M. Sojková , O. Pohorelec , J. Hrdá , T.E. Krajčovičová , A. Kozak , L. Pribusová Slušná , T. Ščepka , M. Hulman , M. Maťko , V. Vretenár , I. Píš , F. Bondino , M. Ťapajna , D. Gregušová
Transition metal dichalcogenides (TMDs) hold significant promise for next-generation electronic devices due to their unique electrical and structural properties. However, the performance of TMD-based devices is strongly influenced by the nature of the metal–semiconductor contacts. Achieving low-resistance, stable, and efficient contacts remains a key challenge and a crucial factor in fully realizing the potential of TMD materials in practical applications. In particular, platinum diselenide (PtSe2) has emerged as a compelling candidate due to its tunable electronic properties and suitability for scalable synthesis. Advanced fabrication and precise contact engineering are key to minimizing interfacial degradation and maximizing device performance.
In this study, epitaxial PtSe2 layers were synthesized on c-plane sapphire, providing an ideal platform for scalable device fabrication. PtSe2-based electronic structures were fabricated by a two-resist lift-off technique combined with a one-zone chalcogenization approach.
We have focused on the systematical contact engineering investigation by evaluating nickel (Ni) and platinum (Pt) as source/drain electrodes. Electrical characterization showed a threefold reduction in Pt contact resistance as compared to Ni. Correlative scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX) confirm that Pt diffuses toward the substrate without disrupting the PtSe2 layers, whereas Ni induces severe top-layer degradation.
To investigate the impact of thickness on device performance, we gradually reduced the thickness of few-layer PtSe2 in Transfer Length Method (TLM) structures with Pt/Au contacts. The films maintained continuous morphology and stable electrical behavior down to 1.5 nm, while further reduction led to increased surface roughness, void formation, and a notable rise in sheet and contact resistance.
These findings highlight the critical role of contact engineering and interface quality in preserving film integrity and optimizing device performance. Moreover, the results offer a scalable fabrication pathway for integrating PtSe2 and related TMDs into high-performance electronic applications.
{"title":"Investigating Ohmic contacts in PtSe2-based electronics","authors":"M. Sojková , O. Pohorelec , J. Hrdá , T.E. Krajčovičová , A. Kozak , L. Pribusová Slušná , T. Ščepka , M. Hulman , M. Maťko , V. Vretenár , I. Píš , F. Bondino , M. Ťapajna , D. Gregušová","doi":"10.1016/j.flatc.2025.100943","DOIUrl":"10.1016/j.flatc.2025.100943","url":null,"abstract":"<div><div>Transition metal dichalcogenides (TMDs) hold significant promise for next-generation electronic devices due to their unique electrical and structural properties. However, the performance of TMD-based devices is strongly influenced by the nature of the metal–semiconductor contacts. Achieving low-resistance, stable, and efficient contacts remains a key challenge and a crucial factor in fully realizing the potential of TMD materials in practical applications. In particular, platinum diselenide (PtSe<sub>2</sub>) has emerged as a compelling candidate due to its tunable electronic properties and suitability for scalable synthesis. Advanced fabrication and precise contact engineering are key to minimizing interfacial degradation and maximizing device performance.</div><div>In this study, epitaxial PtSe<sub>2</sub> layers were synthesized on c-plane sapphire, providing an ideal platform for scalable device fabrication. PtSe<sub>2</sub>-based electronic structures were fabricated by a two-resist lift-off technique combined with a one-zone chalcogenization approach.</div><div>We have focused on the systematical contact engineering investigation by evaluating nickel (Ni) and platinum (Pt) as source/drain electrodes. Electrical characterization showed a threefold reduction in Pt contact resistance as compared to Ni. Correlative scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX) confirm that Pt diffuses toward the substrate without disrupting the PtSe<sub>2</sub> layers, whereas Ni induces severe top-layer degradation.</div><div>To investigate the impact of thickness on device performance, we gradually reduced the thickness of few-layer PtSe<sub>2</sub> in Transfer Length Method (TLM) structures with Pt/Au contacts. The films maintained continuous morphology and stable electrical behavior down to 1.5 nm, while further reduction led to increased surface roughness, void formation, and a notable rise in sheet and contact resistance.</div><div>These findings highlight the critical role of contact engineering and interface quality in preserving film integrity and optimizing device performance. Moreover, the results offer a scalable fabrication pathway for integrating PtSe<sub>2</sub> and related TMDs into high-performance electronic applications.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100943"},"PeriodicalIF":6.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119354","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 : 2025-09-20DOI: 10.1016/j.flatc.2025.100942
Ru-song Li , Ling-Jun Zheng , Kang Li , Jia-huan Zhang , Zheng Xie , Jin-tao Wang , Fei Wang
This study reveals the multifactorial impacts on the electronic properties and irradiation response of transition metal dichalcogenides (TMDs) MS2 (M = Mo, W, V). Employing first-principles calculations, we unravel the intricate interplay between d-electron correlations, magnetic ordering, and van der Waals interactions. Our results highlight that these interactions significantly modulate the band structures and phase stability of TMDs, leading to phenomena such as metal-insulator transitions and bandgap engineering. Additionally, we explore the effects of neutron irradiation on TMDs, revealing defect-induced structural metastability and electronic phase transitions. This work not only enhances our understanding of TMDs but also paves the way for designing advanced electronic and spintronic devices with tailored properties.
{"title":"Unveiling the multifactorial coupling effects on electronic properties and irradiation behavior of transition metal dichalcogenides MS2 (M = Mo, W, V)","authors":"Ru-song Li , Ling-Jun Zheng , Kang Li , Jia-huan Zhang , Zheng Xie , Jin-tao Wang , Fei Wang","doi":"10.1016/j.flatc.2025.100942","DOIUrl":"10.1016/j.flatc.2025.100942","url":null,"abstract":"<div><div>This study reveals the multifactorial impacts on the electronic properties and irradiation response of transition metal dichalcogenides (TMDs) <em>M</em>S<sub>2</sub> (<em>M</em> = Mo, W, V). Employing first-principles calculations, we unravel the intricate interplay between d-electron correlations, magnetic ordering, and van der Waals interactions. Our results highlight that these interactions significantly modulate the band structures and phase stability of TMDs, leading to phenomena such as metal-insulator transitions and bandgap engineering. Additionally, we explore the effects of neutron irradiation on TMDs, revealing defect-induced structural metastability and electronic phase transitions. This work not only enhances our understanding of TMDs but also paves the way for designing advanced electronic and spintronic devices with tailored properties.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100942"},"PeriodicalIF":6.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119432","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}
Phase engineering of MoS monolayers offers a promising strategy to enhance lithium-sulfur (Li–S) battery performance by tuning interfacial chemistry and redox dynamics. Using density functional theory calculations, we compare the semiconducting 2H and metallic 1T′ polymorphs as cathode host materials, analyzing their adsorption energetics, charge transfer, reaction barriers (via the nudged elastic band method), thermodynamic stability (via gas-phase and solvated models), and vibrational responses. We find that 1T′-MoS enables strong polysulfide anchoring and low delithiation barriers, while the reversible 2H1T′ transition provides a tunable balance between conductivity and structural integrity. These findings identify phase-engineered MoS architectures as robust, rate-capable platforms for suppressing the shuttle effect and guiding the design of high-performance Li–S battery cathodes.
{"title":"Phase engineering of MoS2 monolayers: A pathway to enhanced lithium-polysulfide battery performance","authors":"J.W. González , E. Flórez , R.A. Gallardo , J.D. Correa","doi":"10.1016/j.flatc.2025.100938","DOIUrl":"10.1016/j.flatc.2025.100938","url":null,"abstract":"<div><div>Phase engineering of MoS<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> monolayers offers a promising strategy to enhance lithium-sulfur (Li–S) battery performance by tuning interfacial chemistry and redox dynamics. Using density functional theory calculations, we compare the semiconducting 2H and metallic 1T′ polymorphs as cathode host materials, analyzing their adsorption energetics, charge transfer, reaction barriers (via the nudged elastic band method), thermodynamic stability (via gas-phase and solvated models), and vibrational responses. We find that 1T′-MoS<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> enables strong polysulfide anchoring and low delithiation barriers, while the reversible 2H<span><math><mo>↔</mo></math></span>1T′ transition provides a tunable balance between conductivity and structural integrity. These findings identify phase-engineered MoS<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> architectures as robust, rate-capable platforms for suppressing the shuttle effect and guiding the design of high-performance Li–S battery cathodes.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100938"},"PeriodicalIF":6.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097049","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 : 2025-09-16DOI: 10.1016/j.flatc.2025.100939
Maciej J. Szary
Molybdenum-based transition-metal dichalcogenides (TMDs) are promising catalysts for key electro- and photochemical reactions, including CO2 reduction (CRR), N2 reduction (NRR), and hydrogen evolution (HER). However, their catalytic performance is inherently limited by the low reactivity of their basal planes, necessitating structural modifications to expose chemically active transition-metal sites. Here, we provide fundamental insights into chalcogen-vacancy engineering in Mo-based TMDs. Using large-scale density functional theory (DFT) computations, including NVT ab initio molecular dynamics (AIMD) and density functional perturbation theory (DFPT), we examine 400 adsorption cases across three TMD monolayers — MoS2, MoSe2, and MoTe2 — considering both pristine and defective structures with three chalcogen-vacancy sizes, as well as six molecular species (N2, O2, NO, CO, CO2, and NO2). Our findings reveal that vacancy effects are highly selective, with adsorption enhancements varying significantly by molecular species. While larger vacancies generally strengthen adsorption across all TMDs, they also amplify intrinsic physicochemical differences. MoTe2 exhibits the highest binding energies and molecular deformation, followed by MoSe2 and MoS2. Notably, vacancy-engineered TMDs demonstrate promising adsorption for N2 and CO2, with activation-to-binding ratios surpassing many conventional catalysts. By strategically selecting TMD compositions and tailoring vacancy sizes, adsorption strength and molecular activation can be finely optimized, leading to distinct thermodynamic favorability. Our results show defective MoS2 favors CO2 capture and activation for CRR but suppresses NRR and modestly limits HER, whereas MoTe2 suppresses HER while promoting both NRR and CRR. These insights establish chalcogen selection as critical parameter in defect engineering, paving the way for rational design of advanced catalytic materials.
{"title":"Rational design of defect-engineered TMDs: Unlocking active sites for selective capture and catalysis in MoS2, MoSe2, and MoTe2","authors":"Maciej J. Szary","doi":"10.1016/j.flatc.2025.100939","DOIUrl":"10.1016/j.flatc.2025.100939","url":null,"abstract":"<div><div>Molybdenum-based transition-metal dichalcogenides (TMDs) are promising catalysts for key electro- and photochemical reactions, including CO<sub>2</sub> reduction (CRR), N<sub>2</sub> reduction (NRR), and hydrogen evolution (HER). However, their catalytic performance is inherently limited by the low reactivity of their basal planes, necessitating structural modifications to expose chemically active transition-metal sites. Here, we provide fundamental insights into chalcogen-vacancy engineering in Mo-based TMDs. Using large-scale density functional theory (DFT) computations, including NVT ab initio molecular dynamics (AIMD) and density functional perturbation theory (DFPT), we examine 400 adsorption cases across three TMD monolayers — MoS<sub>2</sub>, MoSe<sub>2</sub>, and MoTe<sub>2</sub> — considering both pristine and defective structures with three chalcogen-vacancy sizes, as well as six molecular species (N<sub>2</sub>, O<sub>2</sub>, NO, CO, CO<sub>2</sub>, and NO<sub>2</sub>). Our findings reveal that vacancy effects are highly selective, with adsorption enhancements varying significantly by molecular species. While larger vacancies generally strengthen adsorption across all TMDs, they also amplify intrinsic physicochemical differences. MoTe<sub>2</sub> exhibits the highest binding energies and molecular deformation, followed by MoSe<sub>2</sub> and MoS<sub>2</sub>. Notably, vacancy-engineered TMDs demonstrate promising adsorption for N<sub>2</sub> and CO<sub>2</sub>, with activation-to-binding ratios surpassing many conventional catalysts. By strategically selecting TMD compositions and tailoring vacancy sizes, adsorption strength and molecular activation can be finely optimized, leading to distinct thermodynamic favorability. Our results show defective MoS<sub>2</sub> favors CO<sub>2</sub> capture and activation for CRR but suppresses NRR and modestly limits HER, whereas MoTe<sub>2</sub> suppresses HER while promoting both NRR and CRR. These insights establish chalcogen selection as critical parameter in defect engineering, paving the way for rational design of advanced catalytic materials.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100939"},"PeriodicalIF":6.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097048","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 : 2025-09-10DOI: 10.1016/j.flatc.2025.100940
Yifei Wang , Yue Shi , Yuanyuan Yang , Ziyi Cheng , Hengbo Jia , Yaning Zhou , Le Li
Zinc-ion batteries (ZIBs), emerging as a novel power source, boast benefits like enhanced security, affordability, and eco-friendliness. The real-world use of ZIBs faces obstacles because of the narrow electrochemical stability range, the disintegration of active electrode substances, and inadequate growth and lifespan of zinc dendrites. Owing to their unique structural characteristics as well as physical and chemical properties, including excellent electrical conductivity, adjustable interlayer spaces, low-energy barriers, rich-surface functional groups (e.g., OH, O, Cl, and F), and ample chemical compositions, MXenes-based materials can solve the above-mentioned problems of ZIBs. The paper examines the latest advancements in research on MXenes-based substances (zero dimension, one dimension, two dimension, and three dimension) in ZIBs applications, including MXene-based materials anodes, cathodes, electrolyte, separator and current collectors. Furthermore, an in-depth exploration of the structural design and reaction processes of MXene-based substances in ZIBs is conducted. Lastly, a concise discussion is presented on the current difficulties and viewpoints regarding MXene-based substances for ZIBs.
{"title":"Recent advances in MXene-based materials for zinc-ion batteries","authors":"Yifei Wang , Yue Shi , Yuanyuan Yang , Ziyi Cheng , Hengbo Jia , Yaning Zhou , Le Li","doi":"10.1016/j.flatc.2025.100940","DOIUrl":"10.1016/j.flatc.2025.100940","url":null,"abstract":"<div><div>Zinc-ion batteries (ZIBs), emerging as a novel power source, boast benefits like enhanced security, affordability, and eco-friendliness. The real-world use of ZIBs faces obstacles because of the narrow electrochemical stability range, the disintegration of active electrode substances, and inadequate growth and lifespan of zinc dendrites. Owing to their unique structural characteristics as well as physical and chemical properties, including excellent electrical conductivity, adjustable interlayer spaces, low-energy barriers, rich-surface functional groups (e.g., <img>OH, <img>O, <img>Cl, and <img>F), and ample chemical compositions, MXenes-based materials can solve the above-mentioned problems of ZIBs. The paper examines the latest advancements in research on MXenes-based substances (zero dimension, one dimension, two dimension, and three dimension) in ZIBs applications, including MXene-based materials anodes, cathodes, electrolyte, separator and current collectors. Furthermore, an in-depth exploration of the structural design and reaction processes of MXene-based substances in ZIBs is conducted. Lastly, a concise discussion is presented on the current difficulties and viewpoints regarding MXene-based substances for ZIBs.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100940"},"PeriodicalIF":6.2,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047131","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 : 2025-09-06DOI: 10.1016/j.flatc.2025.100930
Amutha Subramani , Borna Radatović , Jan Luxa , Filipa M. Oliveira , Kalyan Jyoti Sarkar , Chenrayan Senthil , Stefanos Mourdikoudis , David Sedmidubsky , Zdeněk Sofer
The combination of unique narrow bandgap electronic and optical properties, along with van der Waals surfaces in 2D materials, makes this class of materials highly promising for advancing photodetectors. In this study, we employ first-principles calculations to investigate the structural, electronic, and vibrational properties of the 2D CuInP₂Se₆ van der Waals material. Theoretical studies reveal phase-dependent properties in CuInP₂Se₆, including bulk paraelectric, bulk ferroelectric, and monolayer paraelectric phases. Notably, the material exhibits a tunable electronic band structure through phase transitions and layer thickness modulation. Among the explored phases, the paraelectric monolayer demonstrates a strong second harmonic generation response while also displaying lower thermal conductivity, making it suitable for nonlinear optical applications. The theoretically predicted optical properties were validated experimentally by synthesizing CuInP₂Se₆ using multi-step solid-state and chemical vapor transport reactions. A fabricated photodevice, configured as Au/CuInP₂Se₆/SiO₂ via standard optical lithography, exhibited UV–visible photodetection with a maximum photoresponsivity at 405 nm. Similarly, a modelled photodevice with the same configuration also demonstrated photodetection, attaining a maximum photoresponsivity at 405 nm. Furthermore, encapsulating silicene is expected to further modulate the electronic band structure and enhance photodetection performance, paving the way for future advancements in integrated UV–Vis-NIR optoelectronic devices. The significant improvement in photoconductive gain in the NIR range is attributed to an efficient charge transport pathway and interfacial encapsulation.
{"title":"Thickness- tuned band engineering for efficient photodetection in 2D CuInP2Se6","authors":"Amutha Subramani , Borna Radatović , Jan Luxa , Filipa M. Oliveira , Kalyan Jyoti Sarkar , Chenrayan Senthil , Stefanos Mourdikoudis , David Sedmidubsky , Zdeněk Sofer","doi":"10.1016/j.flatc.2025.100930","DOIUrl":"10.1016/j.flatc.2025.100930","url":null,"abstract":"<div><div>The combination of unique narrow bandgap electronic and optical properties, along with van der Waals surfaces in 2D materials, makes this class of materials highly promising for advancing photodetectors. In this study, we employ first-principles calculations to investigate the structural, electronic, and vibrational properties of the 2D CuInP₂Se₆ van der Waals material. Theoretical studies reveal phase-dependent properties in CuInP₂Se₆, including bulk paraelectric, bulk ferroelectric, and monolayer paraelectric phases. Notably, the material exhibits a tunable electronic band structure through phase transitions and layer thickness modulation. Among the explored phases, the paraelectric monolayer demonstrates a strong second harmonic generation response while also displaying lower thermal conductivity, making it suitable for nonlinear optical applications. The theoretically predicted optical properties were validated experimentally by synthesizing CuInP₂Se₆ using multi-step solid-state and chemical vapor transport reactions. A fabricated photodevice, configured as Au/CuInP₂Se₆/SiO₂ via standard optical lithography, exhibited UV–visible photodetection with a maximum photoresponsivity at 405 nm. Similarly, a modelled photodevice with the same configuration also demonstrated photodetection, attaining a maximum photoresponsivity at 405 nm. Furthermore, encapsulating silicene is expected to further modulate the electronic band structure and enhance photodetection performance, paving the way for future advancements in integrated UV–Vis-NIR optoelectronic devices. The significant improvement in photoconductive gain in the NIR range is attributed to an efficient charge transport pathway and interfacial encapsulation.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100930"},"PeriodicalIF":6.2,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097047","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 : 2025-09-05DOI: 10.1016/j.flatc.2025.100929
Adriana C. da Silva , Thiago S. da Sena , Igor G.S. Oliveira , Fausto E. Bimbi Junior , Oswaldo C. Junior , Robson S. Souto , Michael M. Baruch , João P.P. Encide , Kathia M. Honorio , Marcos R.V. Lanza , Adriana E. de Carvalho , Willyam R.P. Barros
In this study, an inexpensive, easy-to-make screen-printed electrochemical (SPE) sensor was developed and applied for diuron (DIU) detection in Brazilian crops. The SPE was modified with a hybrid nanocomposite, which consisted of functionalized carbon nanotubes, chitosan and silver nanoparticles (f-MWCNT@Chi-AgNPs). The AgNPs were obtained through a simple and rapid green synthesis using lemon leaf extract as a reducing agent. The sensor exhibits irreversible electrochemical behavior with a diffusion-controlled response. The SPE-modified sensor when applied for DIU detection, was obtained a wide linear range (0.02–50.0 μM), a low LOD (0.005 μM), and a high sensitivity. Experimental variables, such as pH and scan rate were optimized, with pH 7.0 identified as the optimal medium. The modified SPE sensor demonstrated excellent selectivity against common interferents, operational stability, and no memory effect. The DFT analysis, from the M06-2X and B3LYP functionals, and the Def2-SVP basis set, reveals that the DIU molecule is a moderate electrophile. These data suggest the SPE/f-MWCNT@Chi-AgNPs are both highly reactive and stable for DIU oxidation. Its practical applicability was confirmed through the analysis of real samples (orange fruit, orange juice, tangerine, sugarcane and tomato), where recovery rates between 100.09 and 110.61 % were obtained, with RSD below 4.0 %. The combination of conductive materials with porous structure and sustainable synthesis yielded an efficient analytical platform. The proposed sensor can be employed as a viable, rapid and effective alternative tool for monitoring pesticide residues in complex matrices, with strong potential for application in environmental and food quality analysis.
{"title":"Electrochemical determination of Diuron in Brazilian crops: f-MWCNT@Chi-AgNPs nanocomposite-modified screen-printed electrode for food safety monitoring","authors":"Adriana C. da Silva , Thiago S. da Sena , Igor G.S. Oliveira , Fausto E. Bimbi Junior , Oswaldo C. Junior , Robson S. Souto , Michael M. Baruch , João P.P. Encide , Kathia M. Honorio , Marcos R.V. Lanza , Adriana E. de Carvalho , Willyam R.P. Barros","doi":"10.1016/j.flatc.2025.100929","DOIUrl":"10.1016/j.flatc.2025.100929","url":null,"abstract":"<div><div>In this study, an inexpensive, easy-to-make screen-printed electrochemical (SPE) sensor was developed and applied for diuron (DIU) detection in Brazilian crops. The SPE was modified with a hybrid nanocomposite, which consisted of functionalized carbon nanotubes, chitosan and silver nanoparticles (<em>f-</em>MWCNT@Chi-AgNPs). The AgNPs were obtained through a simple and rapid green synthesis using lemon leaf extract as a reducing agent. The sensor exhibits irreversible electrochemical behavior with a diffusion-controlled response. The SPE-modified sensor when applied for DIU detection, was obtained a wide linear range (0.02–50.0 μM), a low LOD (0.005 μM), and a high sensitivity. Experimental variables, such as pH and scan rate were optimized, with pH 7.0 identified as the optimal medium. The modified SPE sensor demonstrated excellent selectivity against common interferents, operational stability, and no memory effect. The DFT analysis, from the M06-2X and B3LYP functionals, and the Def2-SVP basis set, reveals that the DIU molecule is a moderate electrophile. These data suggest the SPE/<em>f-</em>MWCNT@Chi-AgNPs are both highly reactive and stable for DIU oxidation. Its practical applicability was confirmed through the analysis of real samples (orange fruit, orange juice, tangerine, sugarcane and tomato), where recovery rates between 100.09 and 110.61 % were obtained, with RSD below 4.0 %. The combination of conductive materials with porous structure and sustainable synthesis yielded an efficient analytical platform. The proposed sensor can be employed as a viable, rapid and effective alternative tool for monitoring pesticide residues in complex matrices, with strong potential for application in environmental and food quality analysis.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100929"},"PeriodicalIF":6.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019314","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 : 2025-09-04DOI: 10.1016/j.flatc.2025.100927
Nisa Nashrah , Yujun Sheng , Min Jun Kim , Young Gun Ko
This study investigated the uniform deposition of BaTiO3 (BTO) formed on TiO2 layer to attain photocatalytic reduction of 4-nitrophenol. To this end, a two-step method consisting of plasma electrolysis in the alkaline electrolyte and spin coating in the BTO/polyvinyl alcohol (PVA) recipe where BTO appeared to be coordinated readily with PVA was proposed. Since PVA would played important roles in preventing the local agglomeration of BTO as polymeric capping agent as well as facilitating the stable attachment of BTO on porous TiO2 layer as supporting platform, the BTO/PVA@TiO2 catalyst would exhibit the excellent surface reactivity for catalytic reduction from 4-nitrophenol to 4-aminophenol, achieving the efficiency of 90 % in 10 min under the visible light irradiation. It is also found that the apparent rate constant of BTO/PVA@TiO2 sample was higher by one-order than that of porous TiO2 counterpart. This finding was attributed mainly to the improvement in photo-electrochemical behavior and charge transfer between active BTO particles and TiO2.
{"title":"Uniform formation of distinctive BaTiO3/PVA on TiO2 responsible for enhanced photocatalytic reduction in 4-nitrophenol","authors":"Nisa Nashrah , Yujun Sheng , Min Jun Kim , Young Gun Ko","doi":"10.1016/j.flatc.2025.100927","DOIUrl":"10.1016/j.flatc.2025.100927","url":null,"abstract":"<div><div>This study investigated the uniform deposition of BaTiO<sub>3</sub> (BTO) formed on TiO<sub>2</sub> layer to attain photocatalytic reduction of 4-nitrophenol. To this end, a two-step method consisting of plasma electrolysis in the alkaline electrolyte and spin coating in the BTO/polyvinyl alcohol (PVA) recipe where BTO appeared to be coordinated readily with PVA was proposed. Since PVA would played important roles in preventing the local agglomeration of BTO as polymeric capping agent as well as facilitating the stable attachment of BTO on porous TiO<sub>2</sub> layer as supporting platform, the BTO/PVA@TiO<sub>2</sub> catalyst would exhibit the excellent surface reactivity for catalytic reduction from 4-nitrophenol to 4-aminophenol, achieving the efficiency of 90 % in 10 min under the visible light irradiation. It is also found that the apparent rate constant of BTO/PVA@TiO<sub>2</sub> sample was higher by one-order than that of porous TiO<sub>2</sub> counterpart. This finding was attributed mainly to the improvement in photo-electrochemical behavior and charge transfer between active BTO particles and TiO<sub>2</sub>.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100927"},"PeriodicalIF":6.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027373","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}
A novel graphene oxide (GO)-based nanofiltration membrane was engineered to tackle the selective separation challenge of dyes and inorganic salts in salt-laden textile wastewater. Highly hydrophilic sulfobetaine methacrylate (SBMA) was covalently graft-polymerized onto GO surfaces to fabricate amphoteric polymer nanosheets (PSBMA@GO). Subsequent physical intercalation with pristine GO nanosheets yielded the GPM1:2 composite membrane. This strategy effectively enlarged the interlayer channels, endowing the membrane with a significantly enhanced permeability of 31.53 L·m−1 h−1 bar−1, markedly surpassing that of the pristine GO membrane (12.26 L·m−1 h−1 bar−1). The zwitterionic modification preserved the inherent negative charge of GO. The synergistic interplay between membrane surface charge regulation and precise pore size control achieved exceptional dye/salt separation selectivity. Dyes were selectively rejected via the Donnan exclusion effect, with rejection rates for Methylene Blue (MnB) and Congo Red (CR) exceeding 99.47 % and 98.7 %, respectively. Concurrently, efficient permeation of mono/divalent salt ions was facilitated (NaCl: 96.83 %; Na₂SO₄: 95.8 %). Furthermore, the zwitterionic polymer conferred exceptional anti-fouling properties, evidenced by a high flux recovery rate (FRR) of 89.15 % following bovine serum albumin (BSA) fouling. The FRR remained above 80 % even after a rigorous 10-h dynamic cycling test. This study establishes a novel paradigm for designing high-efficiency dye wastewater treatment membranes through the synergistic optimization of interfacial functionalization and structural modulation.
{"title":"Charge-size synergistic screening of GO/PSBMA nanofiltration membranes: for dye desalination and anti-fouling mechanism studies","authors":"Peng Kong, Zeshan Sun, Yibin Liang, Mingtai Xin, Haoxuan Zhang, Yu Song, Yanxin Wang, Jianguo Tang, Linjun Huang","doi":"10.1016/j.flatc.2025.100928","DOIUrl":"10.1016/j.flatc.2025.100928","url":null,"abstract":"<div><div>A novel graphene oxide (GO)-based nanofiltration membrane was engineered to tackle the selective separation challenge of dyes and inorganic salts in salt-laden textile wastewater. Highly hydrophilic sulfobetaine methacrylate (SBMA) was covalently <em>graft</em>-polymerized onto GO surfaces to fabricate amphoteric polymer nanosheets (PSBMA@GO). Subsequent physical intercalation with pristine GO nanosheets yielded the GPM1:2 composite membrane. This strategy effectively enlarged the interlayer channels, endowing the membrane with a significantly enhanced permeability of 31.53 L·m<sup>−1</sup> h<sup>−1</sup> bar<sup>−1</sup>, markedly surpassing that of the pristine GO membrane (12.26 L·m<sup>−1</sup> h<sup>−1</sup> bar<sup>−1</sup>). The zwitterionic modification preserved the inherent negative charge of GO. The synergistic interplay between membrane surface charge regulation and precise pore size control achieved exceptional dye/salt separation selectivity. Dyes were selectively rejected via the Donnan exclusion effect, with rejection rates for Methylene Blue (MnB) and Congo Red (CR) exceeding 99.47 % and 98.7 %, respectively. Concurrently, efficient permeation of mono/divalent salt ions was facilitated (NaCl: 96.83 %; Na₂SO₄: 95.8 %). Furthermore, the zwitterionic polymer conferred exceptional anti-fouling properties, evidenced by a high flux recovery rate (FRR) of 89.15 % following bovine serum albumin (BSA) fouling. The FRR remained above 80 % even after a rigorous 10-h dynamic cycling test. This study establishes a novel paradigm for designing high-efficiency dye wastewater treatment membranes through the synergistic optimization of interfacial functionalization and structural modulation.</div></div>","PeriodicalId":316,"journal":{"name":"FlatChem","volume":"54 ","pages":"Article 100928"},"PeriodicalIF":6.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007647","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}
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