A5062187264- Advanced Photocatalysis Techniques
- Copper-based nanomaterials and applications
- TiO2 Photocatalysis and Solar Cells
- Gas Sensing Nanomaterials and Sensors
- ZnO doping and properties
- Luminescence Properties of Advanced Materials
- Microwave Dielectric Ceramics Synthesis
- Ferroelectric and Piezoelectric Materials
- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- Quantum Dots Synthesis And Properties
- Advancements in Battery Materials
- Transition Metal Oxide Nanomaterials
- Iron oxide chemistry and applications
- Ga2O3 and related materials
- Chalcogenide Semiconductor Thin Films
- Electrocatalysts for Energy Conversion
- Solar-Powered Water Purification Methods
- Advanced Nanomaterials in Catalysis
- Solar Thermal and Photovoltaic Systems
- Multiferroics and related materials
- Conducting polymers and applications
- Nanowire Synthesis and Applications
- Ammonia Synthesis and Nitrogen Reduction
- Thin-Film Transistor Technologies
Ajou University
2016-2025
Materials Science & Engineering
2010-2023
Suwon Research Institute
2015-2021
Government of the Republic of Korea
2019
Konkuk University
2018
Stanford University
2011-2016
Seoul National University
2004-2012
National Renewable Energy Laboratory
2008-2010
Kookmin University
2008-2009
University of Pittsburgh
2008-2009
We report a hierarchically branched TiO2 nanorod structure that serves as model architecture for efficient photoelectrochemical devices it simultaneously offers large contact area with the electrolyte, excellent light-trapping characteristics, and highly conductive pathway charge carrier collection. Under Xenon lamp illumination (UV spectrum matched to AM 1.5G, 88 mW/cm2 total power density), array produces photocurrent density of 0.83 mA/cm2 at 0.8 V versus reversible hydrogen electrode...
We report a scalably synthesized WO3/BiVO4 core/shell nanowire photoanode in which BiVO4 is the primary light-absorber and WO3 acts as an electron conductor. These nanowires achieve highest product of light absorption charge separation efficiencies among BiVO4-based photoanodes to date and, even without added catalyst, produce photocurrent 3.1 mA/cm2 under simulated sunlight incident photon-to-current conversion efficiency ∼60% at 300–450 nm, both potential 1.23 V versus RHE.
A BiVO<sub>4</sub> with a preferred [001] orientation and exposed {001} facets were grown epitaxially on FTO <italic>via</italic> laser ablation, achieving the state-of-the-art photoelectrochemical performance for solar water-oxidation.
We report on reduced graphene oxide (rGO)/mesoporous (mp)-TiO2 nanocomposite based mesostructured perovskite solar cells that show an improved electron transport property owing to the interfacial resistance. The amount of rGO added TiO2 nanoparticles layer was optimized, and their impacts film resistivity, diffusion, recombination time, photovoltaic performance were investigated. rGO/mp-TiO2 reduces resistance when compared mp-TiO2 film, hence, it improves charge collection efficiency. This...
Coupling dissimilar oxides in heterostructures allows the engineering of interfacial, optical, charge separation/transport and transfer properties photoanodes for photoelectrochemical (PEC) water splitting. Here, we demonstrate a double-heterojunction concept based on BiVO4/WO3/SnO2 triple-layer planar heterojunction (TPH) photoanode, which shows simultaneous improvements transport (∼93% at 1.23 V vs RHE) transmittance longer wavelengths (>500 nm). The TPH photoanode was prepared by facile...
Abstract High entropy alloys (HEAs) composed of multi‐metal elements in a single crystal structure are attractive for electrocatalysis. However, identifying the complementary functions each element HEAs is prerequisite. Thus, V x CuCoNiFeMn ( = 0, 0.5, and 1.0) investigated to identify active role vanadium improving electrocatalytic activity hydrogen evolution reaction (HER). Structural studies show successful incorporation HEA. 1.0 (V ‐HEA) shows an overpotential 250 mV versus reversible...
We report a new flame reduction method to generate controllable amount of oxygen vacancies in TiO2 nanowires that leads nearly three times improvement the photoelectrochemical (PEC) water-splitting performance. The has unique advantages high temperature (>1000 °C), ultrafast heating rate, tunable environment, and open-atmosphere operation, so it enables rapid formation (less than one minute) without damaging nanowire morphology crystallinity is even applicable various metal oxides....
The performance of dye-sensitized solar cells (DSSCs) consisting anatase TiO2 nanoparticles that were synthesized via a two-step sol−gel process was investigated using electron transport and optical characterizations. Spherical with the average diameter 20 nm, elongated nanorods an aspect ratio (AR) 5, nanowires AR = 10 synthesized. possess narrow size distribution, high crystallinity, negligible surface defects residual organics, which is very suitable for achieving highly efficient...
For a hematite (α‐Fe 2 O 3 ) photoanode, multiple electron/hole recombination pathways occurring in the bulk, interfaces, and surfaces largely limit its low‐bias performance (low photocurrent density at potential) for photoelectrochemical water splitting. Here, facile rapid three‐step approach is reported to simultaneously reduce these recombinations nanorods (NRs) array leading greatly improved low bias potential. First, flame‐doping enables high concentration of Ti doping without hampering...
Ternary oxides are potential candidates as an electron-transporting material that can replace TiO2 in dye-sensitized solar cells (DSSCs), their electronic/optical properties be easily controlled by manipulating the composition and/or doping. Here, we report a new highly efficient DSSC using perovskite BaSnO3 (BSO) nanoparticles. In addition, effects of TiCl4 treatment on physical, chemical, and photovoltaic BSO-based DSSCs investigated. The was found to form ultrathin layer BSO surface,...
We report an efficient hybrid Si microwire (radial junction) and planar solar cell with a maximum efficiency of 11.0% under AM 1.5G ill;umination. The the is improved from 7.2% to by passivating top surface p–n junction thin a-SiN:H intrinsic poly-Si films, respectively, higher than that cells identical layers due increased light absorption charge-carrier collections in both wires components.
Abstract Using a wet‐chemical method and without any surfactants or templates, various 3D hierarchical superstructures of Cu 2 PO 4 OH were synthesized by simply adjusting the pH. The resulting characterized using X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), high resolution‐TEM (HRTEM), Fourier transform infrared spectroscopy (FTIR), Raman, UV–Vis spectroscopy. With an increase in pH from 2.5 to 7.0, morphology varied microrods walnut‐shaped microspheres...
Novel SnWO4 visible-light active photocatalysts with two polymorphs (orthorhombic α and cubic β phases) were prepared by a conventional solid-state reaction method, their optical properties, electronic band structure, photocatalytic activities investigated. It was found that the low-temperature phase, α-SnWO4 corner-shared WO6 octahedra, exhibited dark-red color indirect gap of 1.64 eV, whereas high-temperature β-SnWO4 unshared WO4 tetrahedra, light-yellow direct 2.68 eV. The Mott−Schottky...
In this study, an aluminum-doped zinc oxide (AZO) layer was used as a transparent conducting (TCO) in ZnO nanowire (NW)-based dye-sensitized solar cells (DSSCs). The well aligned, single crystalline NW arrays that were grown on the AZO films exhibited better DSSC performance (an increased photocurrent density and fill factor) than those fluorine doped tin (FTO) films. I−V characteristics electrochemical impedance spectroscopy measurements for FTO clearly showed superior caused by facilitated...
The realization of efficient photoelectrochemical (PEC) water splitting requires effective integration earth-abundant active oxygen evolution catalysts (OECs) with diverse photoanodes. Although many good OECs have been investigated on conductive substrates under dark conditions, further studies are needed to evaluate their performance when integrated photoanodes illumination. Such will be facilitated by developing coating methods onto Here, we report a one-step hydrothermal process that...
A thorough literature review and the investigation by soft X-ray absorption spectroscopy at synchrotron facilities of Ti-Hematite photoelectrodes are provided.
BaSnO<sub>3</sub> is designed as an electron transport layer of high-efficiency perovskite and dye-sensitized solar cells by fine-tuning energy levels through substitution specific amounts Sr ions.
Photoelectrochemical (PEC) water splitting has been extensively studied as a method to convert sunlight and hydrogen.
We report a synergistic effect of flame and chemical reduction methods to maximize the efficiency solar water splitting in transferred TiO2 nanotube (TNT) arrays on transparent conducting oxide (TCO) substrate. The method (>1000 °C) leads few oxygen vacancies anatase TNT arrays, but it exhibits unique advantages for excellent interfacial characteristics between TCO substrates, which subsequently induce cathodic on-set potential shift sharp photocurrent evolution. By contrast, employed...
Copper ferrite (CuFe2O4) possesses an indirect bandgap in the range of 1.54–1.95 eV. It is used as attractive p-type photocathode photoelectrochemical (PEC) water splitting, and theoretically it can yield a maximum photocurrent density ∼27 mA/cm2 solar-to-hydrogen conversion efficiency ∼33%. To date, only few reports have been published on CuFe2O4 photocathodes with very low-photocurrent densities, value 0.4 at V vs RHE. Herein, we prepared FTO glass sol–gel method followed by either...
High entropy alloys (HEA), multicomponent (5 or more) with an equiatomic a near-equiatomic composition, provide unique platform which to engineer surface composition and active sites for developing of efficient electrocatalysts.