A5043160799- Electronic and Structural Properties of Oxides
- Advanced Photocatalysis Techniques
- Copper-based nanomaterials and applications
- ZnO doping and properties
- Gas Sensing Nanomaterials and Sensors
- Quantum Dots Synthesis And Properties
- Semiconductor materials and devices
- Multiferroics and related materials
- Ga2O3 and related materials
- Trace Elements in Health
- Thin-Film Transistor Technologies
- Catalysis and Hydrodesulfurization Studies
- Nanowire Synthesis and Applications
- Hydrogen Storage and Materials
- Advanced Battery Materials and Technologies
- Transition Metal Oxide Nanomaterials
- Ammonia Synthesis and Nitrogen Reduction
- Iron oxide chemistry and applications
- Organic Electronics and Photovoltaics
- Mine drainage and remediation techniques
- Catalytic Processes in Materials Science
Brookhaven National Laboratory
2015-2021
Stony Brook University
2015-2021
Center for Functional Nanomaterials
2019
Stony Brook Medicine
2016
Fudan University
2012
Ammonia borane (AB) is one of the most promising hydrogen storage materials due to its high content and outstanding environmental stability non-toxicity, which has stimulated substantial effort devoted developing highly efficient dehydrogenation catalysts. Transition metal nanoparticles (NPs) such as iron (Fe) nickel (Ni) are quite attractive their advantages in cost, catalytic activity recycling capability. However, magnetism strong aggregation propensity make it a challenge develop them...
Doping in semiconductor photoelectrodes controls defect formation and carrier transport that critically determine the device performance. Here we report an unconventional relation is tuned by extrinsic molybdenum (Mo) doping BiVO4 photoanodes. Using single-crystalline thin film approach, identify Mo significantly condenses optimization regime between photon collection. For Mo-doped films, unprecedentedly layer (50 nm), less than one-third of pristine thickness, delivers larger photocurrents...
Abstract Here a novel ultrathin lutetium oxide (Lu 2 O 3 ) interlayer is integrated with crystalline bismuth vanadate (BiVO 4 thin film photoanodes to facilitate carrier transport through atomic‐scale interface control. The epitaxial Lu fabricated by pulsed laser deposition features very few structural defects at the back contact of heterojunction, and forms unique band alignment that favors photohole blocking. An optimized thickness 1.4 nm significantly enhances charge separation efficiency...
In semiconductor‐based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at semiconductor/water interface. As a Schottky junction device, trade‐off between photon collection minority remains persistent obstacle for maximizing performance of splitting photoelectrode. Here, it is demonstrated that PEC efficiency an n ‐SrTiO 3 ( ‐STO) photoanode improved very significantly despite its weak indirect band gap optical...
Carrier transport in semiconductor photoelectrodes strongly correlates with intrinsic material characteristics including carrier mobility and diffusion length, extrinsic structural imperfections mobile charged defects at domain boundaries, which collectively determines the photoelectrochemistry (PEC) performance. Here we elucidate interplay between transport, domain-boundary-induced conductivity, PEC water oxidation model photoanode of bismuth vanadate (BiVO4). In particular, epitaxial...
Solution-processable organic semiconductors have potentials as visible photoelectrochemical (PEC) water splitting photoelectrodes due to their tunable small band gap and electronic energy levels, but they are typically limited by poor stability photocatalytic activity. Here, we demonstrate the direct PEC oxidation on solution-processed semiconductor thin films with improved performance ultrathin metal oxide passivation layers. N-type fullerene-derivative passivated sub-2 nm ZnO via atomic...
Semiconductor photoelectrodes for photoelectrochemical (PEC) water splitting require efficient carrier generation, separation, and transport at beyond the space charge region (SCR) formed aqueous interface. The trade-off between photon collection minority delivery governs photoelectrode design implies maximum efficiency an electrode thickness equivalent to light absorption depth. Here, using planar ZnO thin films as a model system, we identify photocarriers SCR another significant source...
A very limited knowledge exists about the effect of non-uniform doping epitaxially grown strontium titanate thin film electrodes on their photoelectrochemical performance in water splitting. In this work, splitting photoanodes featuring an n+-n homojunction were fabricated by pulsed laser deposition technique, where epitaxial SrTiO3 films Nb doped n+-SrTiO3 single crystalline substrates. Thermal diffusion niobium from substrates into deposited formed homojunction, which was profiled...
In this work, we explored a facile, scalable and effective method for substantially enhancing photocurrent incident-photon-to-current efficiency of WO3 thin-film photoanodes by mild reduction treatment under low oxygen pressure. Experimental data from photoelectrochemical electrochemical impedance spectroscopies have shown that such can increase the charge carrier density on photoanode surfaces resulting in improvements hole collection recombination. Despite much thinner layer (about 500 nm)...
Here we develop a technique that fine tunes the hydrothermal growth of ZnO nanowires to address difficulties in controlling their conventional one-pot method. In our technique, precursors are separately and slowly supplied with assistance syringe pump, through entire course growth. Compared method, significantly lowered supersaturation helps eliminating competitive homogeneous nucleation improves reproducibility. The degree can be readily tuned by precursor quantity injection rate, thus...
Zinc oxide (ZnO) nanowire arrays have potential applications for various devices such as ultra-violet light emitting diodes and lasers, where photoluminescence of intense near band edge emission without defect emissions is usually desired. Here, we demonstrate, counter-intuitively, that the may become dominant by introducing certain surface defects to ZnO nanowires via engineering. Specifically, (NBE) effectively enhanced after a low pressure O2 plasma treatment sputters off oxygen species...
In situ synchrotron X-ray absorption near-edge structure characterization of thin-film titania growth by atomic layer deposition (ALD) over ZnO nanowires reveals persistent low-coordinated Ti motifs leading to a new picture ALD growth. Through the design and measurement cycles, K-edge spectral data are continuously recorded so as characterize film evolution function cycle number surface changes within time scale cycle. A unified set analysis tools is developed interpret time-series data....
Due to its chemical stability, titania (TiO2) thin films increasingly have significant impact when applied as passivation layers. However, optimization of growth conditions, key achieving essential film quality and effectiveness, is challenging in the few-nanometers thickness regime. Furthermore, atomic-scale structure nominally amorphous coating layers, particularly nanostructured supports, difficult probe. In this Letter, layers grown on ZnO nanowires optimized using specific strategies...
Here we develop a novel technique for preparing high quality Ti-doped hematite thin films photoelectrochemical (PEC) water splitting, through sputtering deposition of metallic iron from an target embedded with titanium (dopants) pellets, followed by thermal oxidation step that turns the metal into doped hematite. It is found domain size can be tuned ∼10 nm to over 100 adjusting atmosphere more oxidative mostly inert. The better crystallinity at larger ensures excellent PEC splitting...
Abstract not Available.