Monodisperse gold nanoclusters are a new branch of nanomaterials with atomically precise molecular structures. Recently, we have developed a “cluster-from-cluster” approach to assemble gold nanoclusters [Au25(SR)18]- (Au25) via atomically precise Au13 precursors. Herein we demonstrate that efficient synthesis of Au36(SR)24 (Au36) nanoclusters can be realized via this facile approach. Ten examples of Au36 with different thiolate ligands have been prepared in high yield (up to 64%). It was found that the steric and electronic factors of aromatic thiolate ligands determine the final products to be Au25 or Au36. This work not only presents a series of atomically precise Au36 nanoclusters, but also indicates that the “cluster-from-cluster” approach is a practical approach for high-yield preparation of metal nanoclusters.
{"title":"Efficient Synthesis of Au36(SR)24 Nanoclusters via Cluster-From-Cluster Approach","authors":"Yan-Yan Lin, Zi-Ang Nan, Zhen Lei, Quan-Ming Wang","doi":"10.1039/d5nr00203f","DOIUrl":"https://doi.org/10.1039/d5nr00203f","url":null,"abstract":"Monodisperse gold nanoclusters are a new branch of nanomaterials with atomically precise molecular structures. Recently, we have developed a “cluster-from-cluster” approach to assemble gold nanoclusters [Au25(SR)18]- (Au25) via atomically precise Au13 precursors. Herein we demonstrate that efficient synthesis of Au36(SR)24 (Au36) nanoclusters can be realized via this facile approach. Ten examples of Au36 with different thiolate ligands have been prepared in high yield (up to 64%). It was found that the steric and electronic factors of aromatic thiolate ligands determine the final products to be Au25 or Au36. This work not only presents a series of atomically precise Au36 nanoclusters, but also indicates that the “cluster-from-cluster” approach is a practical approach for high-yield preparation of metal nanoclusters.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"33 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518486","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}
Amanda Figueiredo Pereira, Camilla K. B. Q. M. de Oliveira, Aldo J.G. Zarbin, Ariane Schmidt, Bernardo Ruegger Almeida Neves
Scanning probe microscopy (SPM) encompasses a versatile set of characterization techniques that reveal different properties and characteristics of materials. Herein we demonstrate the potential of combining different SPM modes to understand the interactions (and their properties) between the components in two-dimensional/two-dimensional nanoarchitected thin films: graphene oxide (GO)/molybdenum disulfide (MoS2) and reduced graphene oxide (rGO)/MoS2. The films were prepared through the liquid-liquid interfacial route and analyzed by atomic force microscopy in topographic and phase contrast images, Kelvin probe force microscopy, lateral force microscopy and peak force microscopy. It was shown that the presence of oxygenated surface groups, the occurrence of structural defects and the surface electrical potential significantly affects the films morphology and properties. Due to the effective electrostatic interaction, the very small MoS2 flakes are uniformly distributed over the rGO flakes, whereas in an opposite way, they tend to agglomerate in the GO sheets. As a result, the GO/MoS2 film exhibits a Young's modulus of 30 GPa, which is lower than the film containing neat GO (78 GPa), due to an increase in both deformation (2.6 nm) and adhesion (7.2 nN). Otherwise, stiffness increases from 15 GPa to 25 GPa from neat rGO to rGO/MoS2 nanocomposite, in which was observed that the presence of MoS2 increases the friction and promotes a n-type doping. Based on the different SPM modes, it was possible to correlate the structural and morphological characteristics with some mechanical and electrical properties of bicomponent thin films, as well as probe the specific interactions between the components.
{"title":"Probing the Interactions in Graphene Oxide/MoS2 and Reduced Graphene Oxide/MoS2 Nanoarchitectures Using Multimodal Scanning Probe Microscopy","authors":"Amanda Figueiredo Pereira, Camilla K. B. Q. M. de Oliveira, Aldo J.G. Zarbin, Ariane Schmidt, Bernardo Ruegger Almeida Neves","doi":"10.1039/d5nr00341e","DOIUrl":"https://doi.org/10.1039/d5nr00341e","url":null,"abstract":"Scanning probe microscopy (SPM) encompasses a versatile set of characterization techniques that reveal different properties and characteristics of materials. Herein we demonstrate the potential of combining different SPM modes to understand the interactions (and their properties) between the components in two-dimensional/two-dimensional nanoarchitected thin films: graphene oxide (GO)/molybdenum disulfide (MoS2) and reduced graphene oxide (rGO)/MoS2. The films were prepared through the liquid-liquid interfacial route and analyzed by atomic force microscopy in topographic and phase contrast images, Kelvin probe force microscopy, lateral force microscopy and peak force microscopy. It was shown that the presence of oxygenated surface groups, the occurrence of structural defects and the surface electrical potential significantly affects the films morphology and properties. Due to the effective electrostatic interaction, the very small MoS2 flakes are uniformly distributed over the rGO flakes, whereas in an opposite way, they tend to agglomerate in the GO sheets. As a result, the GO/MoS2 film exhibits a Young's modulus of 30 GPa, which is lower than the film containing neat GO (78 GPa), due to an increase in both deformation (2.6 nm) and adhesion (7.2 nN). Otherwise, stiffness increases from 15 GPa to 25 GPa from neat rGO to rGO/MoS2 nanocomposite, in which was observed that the presence of MoS2 increases the friction and promotes a n-type doping. Based on the different SPM modes, it was possible to correlate the structural and morphological characteristics with some mechanical and electrical properties of bicomponent thin films, as well as probe the specific interactions between the components.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"9 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518485","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}
Zihan Gao, Haiyao Yang, Jianzhi Zhang, Jie Yang, Lihong Hong, Zhiyuan Li
Raman spectroscopy has demonstrated significant potential in molecular detection, analysis, and identification, particularly when it adopts single-molecule surface-enhanced Raman scattering (SM-SERS) substrates. A recent SM-SERS scheme incorporates two-fold Raman enhancement mechanisms, the electromagnetic enhancement enabled by plasmonic nanogap hotspot formed from gold sphere nanoparticle sitting on gold mirror and the chemical enhancement enabled by two-dimensional material WS2 inserted into the nanogap. In this work we integrate multiple advanced concepts and techniques to achieve remarkable performance improvements of SM-SERS. We have used hollow gold nanoparticles to form plasmonic nanogaps, which better matches the wavelength of near-infrared pump lasers, thus maximizing the electromagnetic field enhancement within the nanogap and creating a more effective hotspot. Notably, our strategy has achieved universal, robust, fast, and uniform SM-SERS detection for three dye molecules (Rhodamine B, Rhodamine 6G and Crystal Violet) with a detection limit of 10^-16 mol/L. This innovative approach opens up new possibilities for bringing state-of-the-art optical imaging, monitoring, and spectroscopy technologies into single molecule science arena for disclosing more unknown physical, chemical, and biological properties and principles.
{"title":"Hollow Au Nanoparticles for Single-Molecule Raman Spectroscopy via Synergic Electromagnetic and Chemical Enhancement Strategy","authors":"Zihan Gao, Haiyao Yang, Jianzhi Zhang, Jie Yang, Lihong Hong, Zhiyuan Li","doi":"10.1039/d4nr05311g","DOIUrl":"https://doi.org/10.1039/d4nr05311g","url":null,"abstract":"Raman spectroscopy has demonstrated significant potential in molecular detection, analysis, and identification, particularly when it adopts single-molecule surface-enhanced Raman scattering (SM-SERS) substrates. A recent SM-SERS scheme incorporates two-fold Raman enhancement mechanisms, the electromagnetic enhancement enabled by plasmonic nanogap hotspot formed from gold sphere nanoparticle sitting on gold mirror and the chemical enhancement enabled by two-dimensional material WS2 inserted into the nanogap. In this work we integrate multiple advanced concepts and techniques to achieve remarkable performance improvements of SM-SERS. We have used hollow gold nanoparticles to form plasmonic nanogaps, which better matches the wavelength of near-infrared pump lasers, thus maximizing the electromagnetic field enhancement within the nanogap and creating a more effective hotspot. Notably, our strategy has achieved universal, robust, fast, and uniform SM-SERS detection for three dye molecules (Rhodamine B, Rhodamine 6G and Crystal Violet) with a detection limit of 10^-16 mol/L. This innovative approach opens up new possibilities for bringing state-of-the-art optical imaging, monitoring, and spectroscopy technologies into single molecule science arena for disclosing more unknown physical, chemical, and biological properties and principles.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"33 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526509","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}
Qian Mao, Siavash Rajabpour, Mahdi Khajeh Talkhoncheh, Jiadeng Zhu, Malgorzata Kowalik, Adri C. T. van Duin
Correction for ‘Cost-effective carbon fiber precursor selections of polyacrylonitrile-derived blend polymers: carbonization chemistry and structural characterizations’ by Qian Mao et al., Nanoscale, 2022, 14, 6357–6372, https://doi.org/10.1039/D2NR00203E.
{"title":"Correction: Cost-effective carbon fiber precursor selections of polyacrylonitrile-derived blend polymers: carbonization chemistry and structural characterizations","authors":"Qian Mao, Siavash Rajabpour, Mahdi Khajeh Talkhoncheh, Jiadeng Zhu, Malgorzata Kowalik, Adri C. T. van Duin","doi":"10.1039/d5nr90033f","DOIUrl":"https://doi.org/10.1039/d5nr90033f","url":null,"abstract":"Correction for ‘Cost-effective carbon fiber precursor selections of polyacrylonitrile-derived blend polymers: carbonization chemistry and structural characterizations’ by Qian Mao <em>et al.</em>, <em>Nanoscale</em>, 2022, <strong>14</strong>, 6357–6372, https://doi.org/10.1039/D2NR00203E.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"20 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506880","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 structural design of lightweight MXene-polymer composites has attracted significant interest for enhancing both electromagnetic interference (EMI) shielding performance and mechanical strength, which are critical for practical applications. However, a systematic understanding of how various structural configurations of MXene composites affect EMI shielding is lacking. In this study, lightweight Ti3C2Tx -PVA composites were fabricated in three structural forms hydrogel, aerogel, and compact film while varying the Ti3C2Tx areal density (14 to 20 mg cm⁻²) to elucidate the role of structural design in X-band EMI shielding and mechanical properties. EMI shielding performance depends on the structural configuration and areal density of MXene in Ti3C2Tx-PVA composites. The shielding effectiveness increases with the increasing Ti3C2Tx content in each configuration. At a fixed Ti3C2Tx areal density of 0.02 g cm⁻², the Ti3C2Tx -PVA hydrogel demonstrated the highest shielding effectiveness (SE = 70 dB at 10 GHz), attributed to strong dipole polarization and efficient ionic conduction behavior, followed by the compact film (40 dB) and then the aerogel (21 dB). Notably, the aerogel achieved the highest absorption coefficient (A=0.89) due to the improved impedance matching and pronounced internal reflections, whereas the hydrogels and compact films exhibited reflection-dominated shielding. Furthermore, the incorporation of PVA polymer molecules into Ti3C2Tx MXenes significantly enhanced their mechanical properties across all configurations: the hydrogel achieved high stretchability (636%), the aerogel displayed superior compressive strength (0.215 MPa), and the compact film reached a tensile strength of 56 MPa, each surpassing the performance of its pristine Ti3C2Tx MXene counterpart. Overall, tailoring the structural configuration into a hydrogel, aerogel, or compact film offers versatile routes for optimizing both EMI attenuation and mechanical performance of MXene polymer composites.
{"title":"Comparative Electromagnetic Shielding Performance of Ti₃C₂Tₓ–PVA Composites in Various Structural Forms: Compact Films, Hydrogels, and Aerogels","authors":"Shabbir Madad Naqvi, Tufail Hassan, Aamir Iqbal, Shakir Zaman, Soo Yeong Cho, Noushad Hussain, Xiangmeng Kong, Zubair Khalid, Zhiwang Hao, Chong Min Koo","doi":"10.1039/d5nr00450k","DOIUrl":"https://doi.org/10.1039/d5nr00450k","url":null,"abstract":"The structural design of lightweight MXene-polymer composites has attracted significant interest for enhancing both electromagnetic interference (EMI) shielding performance and mechanical strength, which are critical for practical applications. However, a systematic understanding of how various structural configurations of MXene composites affect EMI shielding is lacking. In this study, lightweight Ti3C2Tx -PVA composites were fabricated in three structural forms hydrogel, aerogel, and compact film while varying the Ti3C2Tx areal density (14 to 20 mg cm⁻²) to elucidate the role of structural design in X-band EMI shielding and mechanical properties. EMI shielding performance depends on the structural configuration and areal density of MXene in Ti3C2Tx-PVA composites. The shielding effectiveness increases with the increasing Ti3C2Tx content in each configuration. At a fixed Ti3C2Tx areal density of 0.02 g cm⁻², the Ti3C2Tx -PVA hydrogel demonstrated the highest shielding effectiveness (SE = 70 dB at 10 GHz), attributed to strong dipole polarization and efficient ionic conduction behavior, followed by the compact film (40 dB) and then the aerogel (21 dB). Notably, the aerogel achieved the highest absorption coefficient (A=0.89) due to the improved impedance matching and pronounced internal reflections, whereas the hydrogels and compact films exhibited reflection-dominated shielding. Furthermore, the incorporation of PVA polymer molecules into Ti3C2Tx MXenes significantly enhanced their mechanical properties across all configurations: the hydrogel achieved high stretchability (636%), the aerogel displayed superior compressive strength (0.215 MPa), and the compact film reached a tensile strength of 56 MPa, each surpassing the performance of its pristine Ti3C2Tx MXene counterpart. Overall, tailoring the structural configuration into a hydrogel, aerogel, or compact film offers versatile routes for optimizing both EMI attenuation and mechanical performance of MXene polymer composites.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"129 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506884","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}
Jyoti Saxena, Rahul Murali, Avari Roy, Abdullah Al-Kahtani, Venugopal Rao Soma, Sai Santosh Kumar Raavi, Aditya Sadhanala
Achieving efficient pure-red emission in perovskite-based high-definition display applications remains challenging due to persistent spectral, thermodynamic, and operational instability. Although significant progress has been made using red-emitting quasi-2D perovskites, quantum dots, and mixed-halide perovskites, their performance under operational conditions often remains limited. Here, we address these challenges by embedding mixed-halide perovskite nanocrystals (PeNCs) into a polymer matrix to create a donor-acceptor architecture. This hybrid system stabilizes the nanocrystals and enables efficient energy transfer via Förster resonance energy transfer (FRET). We observe enhanced acceptor photoluminescence and reduced donor lifetimes, confirming the effective FRET-mediated energy transfer arising from optimal spectral overlap. With a FRET rate of 0.18 ps⁻¹ and a FRET efficiency of 88.9%, our approach provides spectrally stable, enhanced pure-red emission. Moreover, it demonstrates a pathway for designing customized energy cascades, paving the way for next-generation optoelectronic devices with improved stability and performance.
{"title":"FRET-Driven Hybrid Polymer–Perovskite Matrices for Efficient Pure-Red Emission","authors":"Jyoti Saxena, Rahul Murali, Avari Roy, Abdullah Al-Kahtani, Venugopal Rao Soma, Sai Santosh Kumar Raavi, Aditya Sadhanala","doi":"10.1039/d4nr05253f","DOIUrl":"https://doi.org/10.1039/d4nr05253f","url":null,"abstract":"Achieving efficient pure-red emission in perovskite-based high-definition display applications remains challenging due to persistent spectral, thermodynamic, and operational instability. Although significant progress has been made using red-emitting quasi-2D perovskites, quantum dots, and mixed-halide perovskites, their performance under operational conditions often remains limited. Here, we address these challenges by embedding mixed-halide perovskite nanocrystals (PeNCs) into a polymer matrix to create a donor-acceptor architecture. This hybrid system stabilizes the nanocrystals and enables efficient energy transfer via Förster resonance energy transfer (FRET). We observe enhanced acceptor photoluminescence and reduced donor lifetimes, confirming the effective FRET-mediated energy transfer arising from optimal spectral overlap. With a FRET rate of 0.18 ps⁻¹ and a FRET efficiency of 88.9%, our approach provides spectrally stable, enhanced pure-red emission. Moreover, it demonstrates a pathway for designing customized energy cascades, paving the way for next-generation optoelectronic devices with improved stability and performance.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"23 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506963","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}
Alejandro Nicolas Filippin, Ángel Campos, Juan Delgado-Alvarez, Gloria Moreno-Martinez, Javier Castillo-Seoane, Victor Joaquin Rico, V. Godinho, Angel Barranco, Juan Ramon Ramon Sanchez-Valencia, Ana Borras
This article presents a reproducible and affordable methodology for fabricating organic nanowires (ONWs) and nanotrees (ONTs) light-enhanced conductometric O2 sensors. The protocol is based on a solventless procedure for the formation of high-density arrays of nanowires and nanotrees on interdigitated electrodes. The synthesis combines physical vapour deposition for the self-assembled growth of free-phthalocyanine nanowires and soft plasma etching to prompt the nucleation sites on the as-grown OWNs to allow for the formation of nanotrees. Electrical conductivity in such low-dimensional electrodes is analysed in the context of density, length, and interconnection between nanowires and nanotrees. Further, the electrodes are immersed in water to improve the nanowires' connectivity. The response of the nanotrees as conductometric O2 sensors is tested under different temperatures (from room temperature to 100 ºC), demonstrating that the higher surface area exposed by the nanotrees in comparison with polycrystalline thin film counterparts, effectively enhances the doping effect of oxygen and increases the response of the ONTs-based sensor. Both organic nanowires and nanotrees were applied as model systems to study the enhanced response of the sensors provided by illumination with white or monochromatic light to the organic semiconducting systems. Interestingly, the otherwise negligible sensor response at room temperature can be activated (On/Off) under LED illumination, and no dependency on the illumination wavelength for the visible range was observed. Thus, under low-power LED illumination with white light, we show a response to O2 of 16 % and 37 % in resistivity for organic nanotrees at room temperature and 100ºC, respectively. These results open the path to developing room temperature long-lasting gas sensors based on one and three-dimensional single-crystalline small-molecule nanowires.
{"title":"Facile integration of single crystalline phthalocyanine nanowires and nanotrees as photoenhanced conductometric sensors","authors":"Alejandro Nicolas Filippin, Ángel Campos, Juan Delgado-Alvarez, Gloria Moreno-Martinez, Javier Castillo-Seoane, Victor Joaquin Rico, V. Godinho, Angel Barranco, Juan Ramon Ramon Sanchez-Valencia, Ana Borras","doi":"10.1039/d4nr04761c","DOIUrl":"https://doi.org/10.1039/d4nr04761c","url":null,"abstract":"This article presents a reproducible and affordable methodology for fabricating organic nanowires (ONWs) and nanotrees (ONTs) light-enhanced conductometric O2 sensors. The protocol is based on a solventless procedure for the formation of high-density arrays of nanowires and nanotrees on interdigitated electrodes. The synthesis combines physical vapour deposition for the self-assembled growth of free-phthalocyanine nanowires and soft plasma etching to prompt the nucleation sites on the as-grown OWNs to allow for the formation of nanotrees. Electrical conductivity in such low-dimensional electrodes is analysed in the context of density, length, and interconnection between nanowires and nanotrees. Further, the electrodes are immersed in water to improve the nanowires' connectivity. The response of the nanotrees as conductometric O2 sensors is tested under different temperatures (from room temperature to 100 ºC), demonstrating that the higher surface area exposed by the nanotrees in comparison with polycrystalline thin film counterparts, effectively enhances the doping effect of oxygen and increases the response of the ONTs-based sensor. Both organic nanowires and nanotrees were applied as model systems to study the enhanced response of the sensors provided by illumination with white or monochromatic light to the organic semiconducting systems. Interestingly, the otherwise negligible sensor response at room temperature can be activated (On/Off) under LED illumination, and no dependency on the illumination wavelength for the visible range was observed. Thus, under low-power LED illumination with white light, we show a response to O2 of 16 % and 37 % in resistivity for organic nanotrees at room temperature and 100ºC, respectively. These results open the path to developing room temperature long-lasting gas sensors based on one and three-dimensional single-crystalline small-molecule nanowires.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"11 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506885","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}
Raul Morales, Stefan T. Bromley, Ilker Demiroglu, Francesc Viñes
ZnO nanostructures have huge potential in a wide range of technologies, including photocatalysis, optoelectronics, and energy harvesting. ZnO commonly exhibits the wurtzite polymorphic phase (wz-ZnO), and one of the few inorganic materials where nanoscale structural phase engineering has revealed alternative polymorphs. These structurally novel nanophases also have properties (e.g. mechanical, electronic) that differ from those of wz-ZnO, and thus may pave the way to new applications. Here we follow the strain-induced transformation between the body centred cubic phase (BCT-ZnO) and the graphitic phase (g-ZnO), which has been experimentally demonstrated in ZnO nanowires. Using free-standing ZnO nanofilms a reference nanosystem, we use density functional theory based calculations to follow the BCT-ZnO ↔ g-ZnO phase transformation relative to systematic changes in in-plane biaxial strain and nanofilm thickness. Tensile strain favours the BCT-ZnO phase, whereas compressive strain induces the transformation to the g-ZnO phase. As the application of nanoscale ZnO usually take advantage of its semiconducting nature, we mainly focus on the variance of the band gap and the character the band edges. Our work strongly features the use of Crystal Orbital Hamilton Population (COHP) analysis, which helps provide a uniquely detailed understanding of this complex nanosystem based on orbital overlap. We use this approach to reveal how strain and quantum confinement (through nanofilm thickness) have distinct and significant effects the on the structural and electronic properties of both BCT-ZnO and g-ZnO phases. The latter phase is particularly interesting as it involves a subtle competition between two structural phases (the layered-ZnO and hex-ZnO phases). These phases can be distinguished by their respective orbital overlap characteristics which, in turn, can be finely tuned by strain and thickness. We propose that the rich electronic properties of this nanosystem can be interpreted through a monolayer superlattice model in which localised surface states and more spatially delocalised quantum confined states compete. More generally our work illustrates how the intricate interplay of strain, quantum confinement and structural phase transformations in an inorganic nanosystem can be analysed and understood through use of COHP analysis of orbital overlap contributions.
{"title":"Tuning the Electronic Properties of ZnO Nanofilms via Strain-induced Structural Phase Transformations and Quantum Confinement","authors":"Raul Morales, Stefan T. Bromley, Ilker Demiroglu, Francesc Viñes","doi":"10.1039/d4nr05206d","DOIUrl":"https://doi.org/10.1039/d4nr05206d","url":null,"abstract":"ZnO nanostructures have huge potential in a wide range of technologies, including photocatalysis, optoelectronics, and energy harvesting. ZnO commonly exhibits the wurtzite polymorphic phase (wz-ZnO), and one of the few inorganic materials where nanoscale structural phase engineering has revealed alternative polymorphs. These structurally novel nanophases also have properties (e.g. mechanical, electronic) that differ from those of wz-ZnO, and thus may pave the way to new applications. Here we follow the strain-induced transformation between the body centred cubic phase (BCT-ZnO) and the graphitic phase (g-ZnO), which has been experimentally demonstrated in ZnO nanowires. Using free-standing ZnO nanofilms a reference nanosystem, we use density functional theory based calculations to follow the BCT-ZnO ↔ g-ZnO phase transformation relative to systematic changes in in-plane biaxial strain and nanofilm thickness. Tensile strain favours the BCT-ZnO phase, whereas compressive strain induces the transformation to the g-ZnO phase. As the application of nanoscale ZnO usually take advantage of its semiconducting nature, we mainly focus on the variance of the band gap and the character the band edges. Our work strongly features the use of Crystal Orbital Hamilton Population (COHP) analysis, which helps provide a uniquely detailed understanding of this complex nanosystem based on orbital overlap. We use this approach to reveal how strain and quantum confinement (through nanofilm thickness) have distinct and significant effects the on the structural and electronic properties of both BCT-ZnO and g-ZnO phases. The latter phase is particularly interesting as it involves a subtle competition between two structural phases (the layered-ZnO and hex-ZnO phases). These phases can be distinguished by their respective orbital overlap characteristics which, in turn, can be finely tuned by strain and thickness. We propose that the rich electronic properties of this nanosystem can be interpreted through a monolayer superlattice model in which localised surface states and more spatially delocalised quantum confined states compete. More generally our work illustrates how the intricate interplay of strain, quantum confinement and structural phase transformations in an inorganic nanosystem can be analysed and understood through use of COHP analysis of orbital overlap contributions.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"51 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506881","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 growing demand for lightweight, flexible, semi-transparent and low-cost photodetectors (PDs) in wearable electronics and optical communication systems has promoted studies to investigate organic materials as feasible alternatives to conventional inorganic PDs. However, modern organic PDs often demonstrate responsivity, detectivity, and photoresponse speed limitations, particularly in the visible range. Here, we report the photoresponse of the organic single-crystal analogue of the Green Fluorescent Protein (GFP) chromophore photodetector device fabricated on silicon nitride substrates. A significant rise in photocurrent was reported under the illumination of visible wavelengths (532 nm, 630 nm, and Halogen light). The observed photoresponse is remarkably convincing and repetitive during ON/OFF cycles of laser light illumination. The voltage dependence of photocurrent is noticed for the device. The photocurrent, rise & decay times, responsivity, detectivity, noise equivalent power and external quantum efficiency are studied for different wavelengths. Strikingly, the fabricated device demonstrates excellent performance in the visible region compared to several conventional organic and inorganic PDs. The responsivity and detectivity are observed to be as large as 98mA/W and 7.94 x 108 Jones respectively. Furthermore, the device demonstrates fast photoresponse dynamics with a rise time of 180 ms and a decay time of 152 ms. The high-performing photodetection properties indicated that the Single-crystal GFP analogue could be used as a broadband material for future optoelectronic applications.
{"title":"Investigating visible range photoresponse of organic single-crystal of green fluorescent protein analogue","authors":"Vishal Digambar Virole, Niteen B Dabke, Sahil Verma, Ajay Kumar, Rinu Pandya, Sudhir Husale, Kumar Vanka, Rajesh G. Gonnade, Rajesh Kanawade","doi":"10.1039/d4nr05252h","DOIUrl":"https://doi.org/10.1039/d4nr05252h","url":null,"abstract":"The growing demand for lightweight, flexible, semi-transparent and low-cost photodetectors (PDs) in wearable electronics and optical communication systems has promoted studies to investigate organic materials as feasible alternatives to conventional inorganic PDs. However, modern organic PDs often demonstrate responsivity, detectivity, and photoresponse speed limitations, particularly in the visible range. Here, we report the photoresponse of the organic single-crystal analogue of the Green Fluorescent Protein (GFP) chromophore photodetector device fabricated on silicon nitride substrates. A significant rise in photocurrent was reported under the illumination of visible wavelengths (532 nm, 630 nm, and Halogen light). The observed photoresponse is remarkably convincing and repetitive during ON/OFF cycles of laser light illumination. The voltage dependence of photocurrent is noticed for the device. The photocurrent, rise & decay times, responsivity, detectivity, noise equivalent power and external quantum efficiency are studied for different wavelengths. Strikingly, the fabricated device demonstrates excellent performance in the visible region compared to several conventional organic and inorganic PDs. The responsivity and detectivity are observed to be as large as 98mA/W and 7.94 x 108 Jones respectively. Furthermore, the device demonstrates fast photoresponse dynamics with a rise time of 180 ms and a decay time of 152 ms. The high-performing photodetection properties indicated that the Single-crystal GFP analogue could be used as a broadband material for future optoelectronic applications.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"24 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506883","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}
Giulia Tuci, Miriam Moro, Andrea Rossin, Claudio Evangelisti, Lorenzo Poggini, Marco Etzi, Enrico Verlato, Francesco Paolucci, Yuefeng Liu, Giovanni Valenti, Giuliano Giambastiani
A homogeneous and almost monodisperse Ni/CTFph composite of ultrasmall Ni NPs (~ 2.2 nm) has been prepared by Metal Vapor Synthesis (MVS) deposited on a highly porous and high specific surface area Covalent Triazine Network. Metal-doping was deliberately carried out on a metal-free system exhibiting - as such - superior CO2RR selectivity towards the challenging CO2-to-HCOOH electroreduction. Electrochemical studies aimed at shedding light on the CO2RR performance of the ultimate composite, has allowed to speculate on the synergistic or exclusive action of the two potentially active phases (N-doped C-network vs. Ni NPs). At odds with a generally exclusive CO2-to-CO reduction mechanism described for Ni NPs-based CO2RR electrocatalysts of the state-of-the-art, Ni/CTFph has unveiled the unprecedented aptitude of Ni NPs to promote the alternative and more challenging 2e- CO2-to-HCOOH reduction path, already under moderately reducing potentials (-0.3 V vs. RHE).
{"title":"Commuting CO2 Electro-Reduction Active Sites on a Nickel-Based Hybrid Formed on a 'Guilty' Covalent Triazine Framework","authors":"Giulia Tuci, Miriam Moro, Andrea Rossin, Claudio Evangelisti, Lorenzo Poggini, Marco Etzi, Enrico Verlato, Francesco Paolucci, Yuefeng Liu, Giovanni Valenti, Giuliano Giambastiani","doi":"10.1039/d4nr05259e","DOIUrl":"https://doi.org/10.1039/d4nr05259e","url":null,"abstract":"A homogeneous and almost monodisperse Ni/CTFph composite of ultrasmall Ni NPs (~ 2.2 nm) has been prepared by Metal Vapor Synthesis (MVS) deposited on a highly porous and high specific surface area Covalent Triazine Network. Metal-doping was deliberately carried out on a metal-free system exhibiting - as such - superior CO2RR selectivity towards the challenging CO2-to-HCOOH electroreduction. Electrochemical studies aimed at shedding light on the CO2RR performance of the ultimate composite, has allowed to speculate on the synergistic or exclusive action of the two potentially active phases (N-doped C-network vs. Ni NPs). At odds with a generally exclusive CO2-to-CO reduction mechanism described for Ni NPs-based CO2RR electrocatalysts of the state-of-the-art, Ni/CTFph has unveiled the unprecedented aptitude of Ni NPs to promote the alternative and more challenging 2e- CO2-to-HCOOH reduction path, already under moderately reducing potentials (-0.3 V vs. RHE).","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"29 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506882","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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