The photoelectrodes based on III-nitride semiconductors with high energy conversion efficiency especially for those self-driven ones are greatly desirable for hydrogen generation. In this study, highly ordered InGaN/GaN multiple-quantum-well nanorod-based photoelectrodes have been fabricated by a soft UV-curing nano-imprint lithography and a top-down etching technique, which improve the incident photon conversion efficiency (IPCE) from 16% (planar structure) to 42% (@ wavelength = 400 nm). More significantly, the turn-on voltage is reduced low to -0.6 V, which indicates the possibility of achieving self-driven. Furthermore, SiO2/Si3N4 dielectric distributed Bragg reflectors are employed to further improve the IPCE up to 60%. And the photocurrent (@ 1.1 V) is enhanced from 0.37 mA/cm(2) (original planar structure) to 1.5 mA/cm(2). These improvements may accelerate the possible applications for hydrogen generation with high energy-efficiency.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4745013 | PMC |
http://dx.doi.org/10.1038/srep20218 | DOI Listing |
Sci Adv
January 2025
Department of Chemical Engineering, Kansas State University, Manhattan, KS, USA.
Protonic ceramic electrochemical cells (PCECs) can operate at intermediate temperatures (450° to 600°C) for power generation and hydrogen production. However, the operating temperature is still too high to revolutionize ceramic electrochemical cell technology. Lowering the operating temperature to <450°C will enable a wider material choice and reduce system costs.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
Centro de Engenharia Genética e Biologia Molecular (CBMEG), Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil.
Unlabelled: is an anaerobic and thermophilic bacterium that has been genetically engineered for ethanol production at very high yields. However, the underlying reactions responsible for electron flow, redox equilibrium, and how they relate to ethanol production in this microbe are not fully elucidated. Therefore, we performed a series of genetic manipulations to investigate the contribution of hydrogenase genes to high ethanol yield, generating evidence for the importance of hydrogen-reacting enzymes in ethanol production.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Institute of Materials Science & Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
Carbon catalysts have shown promise as an alternative to the currently available energy-intensive approaches for nitrogen fixation (NF) to urea, NH, or related nitrogenous compounds. The primary challenges for NF are the natural inertia of nitrogenous molecules and the competitive hydrogen evolution reaction (HER). Recently, carbon-based materials have made significant progress due to their tunable electronic structure and ease of defect formation.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
This study focuses on achieving high photocatalytic activity using MoS/TiO heterostructures (MOT). To this end, MoS and TiO were synthesized by employing hydrothermal synthesis techniques, and then MoS/TiO heterostructures were synthesized by using 1:1, 1:2, 1:3, and 1:4 ratios of MoS and TiO, respectively. While the structural and electronic changes for the 1:2 and 1:3 ratios were relatively minor, significant modifications in bandgaps and morphology were observed for the 1:1 and 1:4 ratios.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Friedrich Alexander University Erlangen Nuremberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg, Department of Materials Science, GERMANY.
Bottom-up syntheses of carbon nanodots (CND) using solvothermal treatment of citric acid are known to afford nanometer-sized, amorphous polycitric acid-based materials. The addition of suitable co-reactants in the form of in-situ synthesized N-hetero-π-conjugated chromophores facilitates hereby the overall functionalization. Our incentive was to design a CND model that features phenazine (P-CND) - a well-known N-hetero-π-conjugated chromophore - to investigate the influence of the CND matrix on its redox chemistry as well as photochemistry.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!