A5089506493- Advanced Photocatalysis Techniques
- Laser-induced spectroscopy and plasma
- Laser Material Processing Techniques
- Copper-based nanomaterials and applications
- ZnO doping and properties
- Quantum Dots Synthesis And Properties
- TiO2 Photocatalysis and Solar Cells
- Electronic and Structural Properties of Oxides
- Chalcogenide Semiconductor Thin Films
- Iron oxide chemistry and applications
- Electrocatalysts for Energy Conversion
- Advancements in Battery Materials
- Ga2O3 and related materials
- Semiconductor Quantum Structures and Devices
- Organic Light-Emitting Diodes Research
- Nanowire Synthesis and Applications
- Advanced Battery Materials and Technologies
- Analytical chemistry methods development
- Advanced Semiconductor Detectors and Materials
- Gas Sensing Nanomaterials and Sensors
- Diamond and Carbon-based Materials Research
- GaN-based semiconductor devices and materials
- Ocular and Laser Science Research
- Catalytic Processes in Materials Science
- Organic Electronics and Photovoltaics
Khalifa University of Science and Technology
2021-2024
University of California, Berkeley
2015-2024
Institute of New Materials
2021
North China Electric Power University
2021
Clean Energy (United States)
2020
Consorzio Roma Ricerche
2020
University of California System
2011-2019
Berkeley College
2005-2019
Lawrence Berkeley National Laboratory
2009-2018
Institute of High Energy Physics
2014-2017
Room-temperature ultraviolet lasing in semiconductor nanowire arrays has been demonstrated. The self-organized, <0001> oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process. These wide band-gap form natural laser cavities diameters varying from 20 to 150 nanometers lengths up 10 micrometers. Under optical excitation, surface-emitting action was observed at 385 nanometers, an emission linewidth less than 0.3...
When used as a photocatalyst, titanium dioxide (TiO2) absorbs only ultraviolet light, and several approaches, including the use of dopants such nitrogen, have been taken to narrow band gap TiO2. We demonstrated conceptually different approach enhancing solar absorption by introducing disorder in surface layers nanophase TiO2 through hydrogenation. showed that disorder-engineered nanocrystals exhibit substantial solar-driven photocatalytic activities, photo-oxidation organic molecules water...
This article surveys recent developments in the rational synthesis of single-crystalline zinc oxide nanowires and their unique optical properties. The growth ZnO was carried out a simple chemical vapor transport condensation (CVTC) system. Based on our fundamental understanding vapor–liquid–solid (VLS) nanowire mechanism, different levels controls (including positional, orientational, diameter, density control) have been achieved. Power-dependent emission has examined lasing action observed...
The recent discovery of "black" TiO2 nanoparticles with visible and infrared absorption has triggered an explosion interest in the application a diverse set solar energy systems; however, what black nanoparticle really is remains mystery. Here we elucidate more properties try to understand inner workings hydrogenated disorders surface layer surrounding crystalline core. Contrary traditional findings, Ti(3+) here not responsible for TiO2, while there evidence mid-gap states above valence band...
A new form of TiO2 which is black in color has been shown to exhibit high efficiency for photocatalytic reactions under solar radiation [X. Chen, L. Liu, P. Y. Yu, and S. Mao, Science 331, 746 (2011)]. However, the mechanism behind this disorder-engineering process not fully understood. In Letter, based on density functional theory, we describe role hydrogen producing lattice disorder anatase nanocrystals. We clarify further that highly localized nature midgap states results spatial...
A variety of atomically dispersed transition-metal-anchored nitrogen-doped carbon (M–N–C) electrocatalysts have shown encouraging electrochemical CO2 reduction reaction (CO2RR) performance, with the underlying fundamentals central transition-metal atom determined CO2RR activity and selectivity yet remaining unclear. Herein, a universal impregnation-acid leaching method was exploited to synthesize various M–N–C (M: Fe, Co, Ni, Cu) single-atom catalysts (SACs), which revealed d-orbital...
Femtosecond laser ablation was investigated for direct solid sample chemical analysis. The phonon relaxation time in a is of the order 100 fs, which same as pulse duration. For such excitation, there should be little matrix to experience "temperature" during pulse. If surface explodes before photon energy dissipated heat lattice, process produce stoichiometric vapor (elemental fractionation negligible). Based on this hypothesis, NIST glasses were ablated using fs pulses at 800 nm, with...
A perspective on the design of all-oxide heterostructures for application in photoelectrochemical cells solar water splitting is provided. Particular attention paid to those structures which possess nanoscale feature dimensionality, as this type are most likely utilize benefits afforded by formation oxide heterojunctions and show functional behavior relating interfacial region. In context discussion, a novel hetero-nanostructure array, based quantum-confined visible light-active iron(III)...
Given the narrow band gap enabling excellent optical absorption, increased charge carrier density and accelerated surface oxidation reaction kinetics become key points for improved photoelectrochemical performances water splitting over hematite (α-Fe2O3) photoanodes. In this study, a facile inexpensive method was demonstrated to develop core/shell structured α-Fe2O3 nanorod arrays. A thin, Ag-doped overlayer of ~2-3 nm thickness formed along nanorods via ultrasonication treatment...
As the world faces serious energy challenges, development and implementation of renewable technologies become increasingly important. In this article, we offer a glimpse role nanotechnology, in particular, innovations nanostructures nanomaterials, is playing selected technologies. These technologies, based on authors' research interests, include (1) converting sunlight directly into electricity using solar cells; (2) hydrogen fuel by splitting water its constituents; (3) storing solid-state...
First-principle calculations of the electronic structure and magnetic interaction GaN:Gd have been performed within generalized gradient approximation (GGA) density functional theory with on-site Coulomb energy $U$ taken into account (also referred to as $\mathrm{GGA}+U$). The ferromagnetic $p\mathrm{\text{\ensuremath{-}}}d$ coupling is found be over 2 orders magnitude larger than $s\mathrm{\text{\ensuremath{-}}}d$ exchange coupling. experimental colossal moments room-temperature...
An ever growing demand for energy coupled with increasing pollution is forcing us to seek environmentally clean alternative resources substitute fossil fuels. The rapid development of nanomaterials has opened up new avenues the conversion and utilization renewable energy. This article reviews nanostructured materials designed selected applications in utilization. review based on authors' research, particular focus solar hydrogen production, storage topics include photoelectrochemical (PEC)...
A thorough literature review and the investigation by soft X-ray absorption spectroscopy at synchrotron facilities of Ti-Hematite photoelectrodes are provided.