A5057055441- Advanced Photocatalysis Techniques
- CO2 Reduction Techniques and Catalysts
- Advancements in Battery Materials
- Gas Sensing Nanomaterials and Sensors
- Supercapacitor Materials and Fabrication
- Silicon and Solar Cell Technologies
- Semiconductor materials and interfaces
- Advanced Battery Materials and Technologies
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- Advanced Chemical Physics Studies
- MXene and MAX Phase Materials
- Ammonia Synthesis and Nitrogen Reduction
- Transition Metal Oxide Nanomaterials
- Chalcogenide Semiconductor Thin Films
- Advanced Semiconductor Detectors and Materials
- Metal-Organic Frameworks: Synthesis and Applications
- Ga2O3 and related materials
- Conducting polymers and applications
- Metal and Thin Film Mechanics
- Inorganic Chemistry and Materials
- Crystallization and Solubility Studies
- Advanced NMR Techniques and Applications
- Additive Manufacturing and 3D Printing Technologies
- Iron-based superconductors research
Baylor University
2024-2025
North Carolina State University
2023-2024
Virginia Tech
2020-2021
Westinghouse Electric (United States)
1984-1989
University of Kent
1982-1985
Carbon nitride materials can be hosts for transition metal sites, but Mössbauer studies on iron complexes in carbon nitrides have always shown a mixture of environments and oxidation states. Here we describe the synthesis characterization crystalline with stoichiometric sites that all same environment. The material (formula C6N9H2Fe0.4Li1.2Cl, abbreviated PTI/FeCl2) is derived from reacting poly(triazine imide)·LiCl (PTI/LiCl) low-melting FeCl2/KCl flux, followed by anaerobic rinsing...
Controlling the electrochemical interfacial processes that govern durability of electrochromic devices represents a key challenge in developing sustainable and cost-effective smart windows.
Oxygen redox plays a prominent role in enhancing the energy density of Mn-based layered cathodes. However, understanding factors affecting reversibility oxygen is nontrivial due to complicated structural and chemical transformations. Herein, we show that local Mn–O symmetry induced structural/chemical evolutions majorly dictate NaxLiyMn1–yO2 Na cells. with Jahn–Teller distorted MnO6 octahedra undergoes severe Mn dissolution during cycling, which destabilizes transition metal layer resulting...
While recent reports have demonstrated the attachment of molecular catalysts to amorphous, graphitic carbon nitrides (g-CN) for light-driven CO2 reduction, approaches utilization crystalline remained undiscovered. Herein, a functional hybrid photocatalyst system has been found using nitride semiconductor, poly(triazine imide) lithium chloride (PTI-LiCl), with surface-attached CoCl2(qpy-Ph-COOH) catalyst reduction. The attaches PTI-LiCl at concentrations from 0.10 4.30 wt % and exhibits ∼96%...
The strategy of incorporating earth-abundant catalytic centers into light-absorbing architectures is desirable from the viewpoint low cost, toxicity, and versatility at activating small molecules to produce solar-based fuels. Herein, we show that an Fe-bearing quaterpyridine molecular species can be anchored a light-absorbing, crystalline, carbon nitride, i.e., yielding molecular-catalyst/material hybrid capable facilitating selective CO2 reduction in aqueous solution. This material...
Crystallites of Cu-coordinated poly(triazine imide) were synthesized by flux methods and deposited from particle suspensions onto electrodes, yielding sizable current densities for the electrocatalytic reduction CO 2 .
Early transition-metal chalcogenides have garnered recent attention for their optoelectronic properties solar energy conversion. Herein, the first Zr-/Hf-chalcogenides with a main group cation, Ba9Hf3Sn2Se19 (1) and Ba8Zr2SnSe13(Se2) (2), been synthesized. The structure of 1 is formed from isolated SnSe44– tetrahedra distorted HfSe6 octahedra. latter condense via face-sharing trimeric motifs that are further vertex-bridged into chains 1∞[Hf(1)2Hf(2)Se11]10–. 2 comprised tetrahedra, Se22–...
Carbon-nitride materials represent light-absorbing structures composed of earth abundant elements capable being leveraged for semiconductor photocatalysis at their surfaces. This study systematically investigates the addition molecular modifiers in synthesis crystalline carbon nitride, primarily form poly(triazine imide) lithium chloride (PTI-LiCl), to assess effects on materials’ structure, optical bandgap, and photocatalytic activity hydrogen (H2) oxygen (O2) evolution under ultraviolet...
The high-pressure liquid encapsulated Czochralski growth of indium lattice-hardened GaAs, from 3 kg melts, has resulted in low-dislocation, large-diameter crystals which exhibit thermally stable, semi-insulating properties. Post-growth boule annealing is found to be an effective stress-relief treatment, assures high wafer yields and extremely uniform electrical Observed reductions dislocation density for mid 1019 cm−3 In-doped GaAs substrates indicate apparent 28-fold increase the critically...
The onset of plastic yield in undoped and highly indium-doped GaAs, prepared by liquid encapsulated Czochralski (LEC) growth, has been determined uniaxial compression tests over the temperature range 250–600 °C. No distinguishable difference stress is observed between GaAs; however, LEC GaAs exhibits a modest increase strength Bridgman-grown material. absence significant implies that mechanism which indium reduces dislocation density significantly effective only at temperatures near melting point.
A review is presented of the current technical status large-diameter GaAs crystal growth, effects residual impurities, stoichiometric defects and crystalline imperfections on electrical properties undoped semi-insulating GaAs, effectiveness Group III V isovalent, lattice-hardening dopants in yielding dislocation-free, crystals. Factors related to postgrowth annealing, preparation ultraflat, damage-free wafers, which can significantly improve performance yields directly implanted devices...
The role of isovalent dopants in the high-temperature deformation GaAs has been studied temperature range 500–1150 °C. Additions In, Sb, and B increase critical resolved shear stress for at a given strain rate result lowering dislocation density as-grown liquid-encapsulated Czochralski crystals. Phosphorus, because its minor influence on lattice strain, shows little enhancement yield stress. These results are consistent with solute hardening model, which atom surrounded tetrahedrally by four...
The proton N.M.R. relaxation times, T 1 and 1ρ, of solid benzene have been measured as a function hydrostatic pressure up to 1·8×108 Pa. measurements are analysed in terms the reorientational motion molecules. This molecular is found weak dependence an associated activation volume 0·18 molar volume, VM . 1ρ translational self-diffusion has strong ΔV *, 1·4±0·2 was obtained, which consistent with vacancy diffusion mechanism.
Proton n.m.r. relaxation time measurements have been made on bicyclo [2.2.2] octane (BCO) and oct-2-ene (BCOE). Measurements for each sample were throughout the plastic brittle phases, down to 77 K. The results interpreted in terms of various molecular motions occurring solid. Below plastic-brittle phase transition point anisotropic reorientation appears occur. activation enthalpy this motion is 17.1±1.2 17.3±1.2 kJ•mol −1 BCO BCOE respectively. Above a rapid endospherical observed yield an...
The proton N.M.R. relaxation times, T 1 and 1ρ, of solid naphthalene have been measured as a function temperature hydrostatic pressure. Both 1ρ show the same pressure dependence in long correlation time region exhibits minimum close to melting point for H 1=6·4 G. results are analysed terms reorientational motion molecules. This is found strong with an associated activation enthalpy 91±7 kJ mol-1 volume 0·6±0·1 V M, where M molar volume.
Abstract In photocatalysis, the photoabsorber plays a crucial role in reaction. The most important parameters are stability, cost and optical band gap. this work, prominent class of absorbers, namely carbon nitrides (CN), has been investigated. literature, CN is often described as stable, although photodegradation observed. order to retain beneficial properties while improving crystalline phase poly(triazine imide) (PTI) nitride was investigated compared polymeric photocatalytic hydrogen...
Inherently disordered structures of carbon nitrides have hindered an atomic level tunability and understanding their catalytic reactivity. Herein, coordination copper cations within a crystalline nitride, i.e., poly(triazine imide) or CNx, was found to yield two ordered for Cu-CNx wherein one Cu(I) coordinate its intralayer N-triazine groups. The crystallites electrophoretically deposit from aqueous particle suspensions current densities ~10 50 mA/cm2 with concomitant increasing reduction...
Electrolyte electroreflectance and photocapacitance measurements have been performed on In-doped undoped GaAs. They verify that In doping generates large inhomogeneous strains which locally lower the stability of zincblende structure compared to chalcopyrite structure, but it lowers density dislocations antisites. also show EL2 complex is intimately associated with As
The electrode–electrolyte interfacial chemistry determines the durability of electrochromic devices. long‐term cycling stability transition metal (TM) oxide films in acidic electrolyte is impoverished, which a major obstacle towards deep market penetration through sustainable and cost-effective smart windows. research interest nanostructuring TM to improve performance has grown rapidly. However, there are few fundamental studies that investigate mechanism degradation. In this work, we...