A5019782149- Advanced Photocatalysis Techniques
- Gas Sensing Nanomaterials and Sensors
- Copper-based nanomaterials and applications
- Chalcogenide Semiconductor Thin Films
- Transition Metal Oxide Nanomaterials
- ZnO doping and properties
- Electronic and Structural Properties of Oxides
- Quantum Dots Synthesis And Properties
- Catalytic Processes in Materials Science
- Advanced Sensor and Energy Harvesting Materials
- Ga2O3 and related materials
- 2D Materials and Applications
- Nanowire Synthesis and Applications
- TiO2 Photocatalysis and Solar Cells
- Energetic Materials and Combustion
- Advanced Thermoelectric Materials and Devices
- Advanced battery technologies research
- Iron oxide chemistry and applications
- Advanced Fiber Optic Sensors
- Electrocatalysts for Energy Conversion
- Teleoperation and Haptic Systems
- Advanced Semiconductor Detectors and Materials
- Coagulation and Flocculation Studies
- Flame retardant materials and properties
- Advancements in Battery Materials
Worcester Polytechnic Institute
2016-2024
Materials Science & Engineering
2016-2020
University of Worcester
2016-2020
Stanford University
2009-2014
Maharana Pratap University of Agriculture and Technology
2014
Sunshine Hospital
2004
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.
BiVO4 has become the top-performing semiconductor among photoanodes for photoelectrochemical water oxidation. However, are still limited to a fraction of theoretically possible photocurrent at low applied voltages because modest charge transport properties and trade-off between light absorption separation efficiencies. Here, we investigate composed thin layers coated onto Sb-doped SnO2 (Sb:SnO2) nanorod-arrays (Sb:SnO2/BiVO4 NRAs) demonstrate high value product efficiencies (ηabs × ηsep)...
We report an atmospheric, catalyst-free, rapid flame synthesis technique for growing single, branched, and flower-like α-MoO(3) nanobelt arrays on diverse substrates. The growth rate, morphology, surface coverage density of the nanobelts were controlled by varying equivalence ratio, source temperature, substrate material morphology substrate. This is a promising, alternative way to synthesize one-dimensional metal oxide nanostructures in general.
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.
This paper describes a simple and yet rapid flame synthesis method to produce one-dimensional metal oxide nanostructures by directly oxidizing metals in the postflame region of flat flame. Single bicrystal α-Fe2O3 nanoflakes CuO nanoneedles were grown solid diffusion mechanism aligned perpendicularly substrate with surface coverage density 10 per square micrometer. The reached lengths exceeding 20 μm after only min growth. growth rate is attributed large initial heating presence water vapor...
Single crystal γ-Fe(2)O(3) nanowires with 40-60 nm diameters were grown for the first time by single-step atmospheric flame vapor deposition (FVD) axial growth rates up to 5 μm/minute. Because of their superior crystallinity, these FVD are single magnetic domains room temperature coercivities 200 Oe and saturation magnetizations 68 emu/g.
Sustainable use of groundwater is becoming critical in India and requires effective participation from local communities along with technical, social, economic, policy political inputs. Access to for farming also an emotional complex issue as their livelihood survival depends on it. In this article, we report transdisciplinary approaches understanding the issues, challenges options improving sustainability States Gujarat Rajasthan, India. project, called Managed Aquifer Recharge through...
We explore ultrafast carrier dynamics and interactions of photoexcited carriers with lattice vibrational modes in BiVO<sub>4</sub> using time-resolved terahertz spectroscopy first-principles phonon spectrum calculations.
Abstract Significant optical absorption in the blue–green spectral range, high intralayer carrier mobility, and band alignment suitable for water splitting suggest tin disulfide (SnS 2 ) as a candidate material photo‐electrochemical applications. In this work, vertically aligned SnS nanoflakes are synthesized directly on transparent conductive substrates using scalable close space sublimation (CSS) method. Detailed characterization by time‐resolved terahertz photoluminescence spectroscopies...
The nanoscale features in silicon nanowires (SiNWs) can suppress phonon propagation and strongly reduce their thermal conductivities compared to the bulk value. This work measures conductivity along axial direction of SiNW arrays with varying nanowire diameters, doping concentrations, surface roughness, internal porosities using nanosecond transient thermoreflectance. For SiNWs diameters larger than mean free path, porosity substantially reduces conductivity, yielding as low 1 W/m/K highly...
The hybrid structure of nanoparticle-decorated nanowires (NP@NW) combines the merits large specific surface areas for NPs and anisotropic properties NWs is a desirable applications including batteries, dye-sensitized solar cells, photoelectrochemical water splitting, catalysis. Here, we report novel sol-flame method to synthesize NP@NW with two unique characteristics: (1) loading per NW morphology NP chains fanning radially from core (2) intimate contact between NWs. Both features are...
Metal oxides with moderate band gaps are desired for efficient production of hydrogen from sunlight and water via photoelectrochemical (PEC) splitting. Here, we report an α-SnWO4 photoanode synthesized by hydrothermal conversion WO3 films that achieves photon to current at wavelengths up 700 nm (1.78 eV). This is promising overall PEC water-splitting because the flat-band potential voltage photocurrent onset more negative than evolution. Furthermore, utilizes a large portion solar spectrum....
Doping nanowires (NWs) is of crucial importance for a range applications due to the unique properties arising from both impurities' incorporation and nanoscale dimensions. However, existing doping methods face challenge simultaneous control over morphology, crystallinity, dopant distribution concentration at nanometer scale. Here, we present controllable reliable method, which combines versatile solution phase chemistry rapid flame annealing process (sol-flame), dope TiO2 NWs with cobalt...
Reduced amorphous titania has been modeled by removing oxygen atoms to clarify the properties of these materials.
The performance of BiVO4 photoanodes, especially under front-side illumination, is limited by the modest charge transport properties BiVO4. Core/shell nanostructures consisting coated onto a conductive scaffold are promising route to improving BiVO4-based photoanodes. Here, we investigate photoanodes composed thin and uniform layers particles Sb-doped SnO2 (Sb:SnO2) nanotube arrays that were synthesized using sacrificial ZnO template with controllable length packing density. We demonstrate...
Transcutaneous monitoring is a noninvasive method to continuously measure the partial pressures of oxygen and carbon dioxide that diffuse through skin correlate closely with changes in blood gases. However, contemporary commercially available electrochemical-based technology requires heating mechanism bulky, corded, expensive sensing unit. This study aims demonstrate prototype noninvasive, miniaturized monitor uses luminescence-based pressure transcutaneous oxygen, surrogate arterial oxygen....
An electroassisted method is developed to transfer silicon (Si) wire arrays from the Si wafers on which they are grown other substrates while maintaining their original properties and vertical alignment. First, etching used form a sacrificial porous layer underneath wires. Second, separated wafer by electropolishing, enabling separation of The further expanded develop current-induced metal-assisted chemical technique for facile rapid synthesis nanowires with axially modulated porosity.
We enhanced the solar energy conversion efficiency of solution-deposited Bi<sub>2</sub>S<sub>3</sub> by annealing in sulfur vapor at elevated temperature.