Wuhan University of Technology

About: Wuhan University of Technology is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Review on nanoscale Bi-based photocatalysts

Abstract: Nanoscale Bi-based photocatalysts are promising candidates for visible-light-driven photocatalytic environmental remediation and energy conversion. However, the performance of bulk bismuthal semiconductors is unsatisfactory. Increasing efforts have been focused on enhancing the performance of this photocatalyst family. Many studies have reported on component adjustment, morphology control, heterojunction construction, and surface modification. Herein, recent topics in these fields, including doping, changing stoichiometry, solid solutions, ultrathin nanosheets, hierarchical and hollow architectures, conventional heterojunctions, direct Z-scheme junctions, and surface modification of conductive materials and semiconductors, are reviewed. The progress in the enhancement mechanism involving light absorption, band structure tailoring, and separation and utilization of excited carriers, is also introduced. The challenges and tendencies in the studies of nanoscale Bi-based photocatalysts are discussed and summarized.

Novel urea assisted hydrothermal synthesis of hierarchical BiVO4/Bi2O2CO3 nanocomposites with enhanced visible-light photocatalytic activity

Abstract: A novel hydrothermal approach is developed for the first time to synthesize hierarchical BiVO4/Bi2O2CO3 nanocomposites with reactive crystalline facets using urea as a morphology mediator. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, N2 absorption–desorption isotherms and UV–visible diffuse reflectance spectroscopy. The photocatalytic activity of the as-prepared samples was evaluated towards degradation of Rhodomine B (RhB) by visible-light. Our results indicate that both physical parameters and associated photocatalytic activity of BiVO4/Bi2O2CO3 nanocomposites can be tuned by urea concentration and reaction time in the synthesis process. With increasing urea concentration, the specific surface area, pore volume and average pore size increase. Compared to BiVO4 and Bi2O2CO3 bulk counterpart, BiVO4/Bi2O2CO3 nanocomposites show enhanced photocatalytic degradation activity of RhB. The mechanisms for the formation of BiVO4/Bi2O2CO3 nanocomposites and enhanced photoreactivity are discussed.

Functionalized Graphene Oxide Nanocomposite Membrane for Low Humidity and High Temperature Proton Exchange Membrane Fuel Cells

Abstract: Functionalized graphene oxide Nafion nanocomposites (F-GO/Nafion) are presented as a potential proton exchange membrane (PEM) replacement for high temperature PEM fuel cell applications. The GO nanosheets were produced from natural graphite flakes by the modified Hummer’s method and then functionalized by using 3-mercaptopropyl trimethoxysilane (MPTMS) as the sulfonic acid functional group precursor. F-GO/Nafion composite membranes were fabricated by a simplistic solution casting method. Several physicochemical characterization techniques were applied to provide insight into the specific structure and morphology, functional groups, water uptake, and ionic conductivities of the membranes. Proton conductivity and single cell test results demonstrated significant improvements for F-GO/Nafion membranes (4 times) over recast Nafion at 120 °C with 25% humidity.

First principle investigation of halogen-doped monolayer g-C3N4 photocatalyst

Abstract: Element doping is an efficient strategy for tuning the electronic structure and improving the photocatalytic activity of graphitic carbon nitride (g-C3N4). Employing the density functional theory computation performed by CASTEP module, we investigated the band structures, electronic and optical properties of monolayer g-C3N4 doped with halogens (F, Cl, Br or I). First, the halogen atoms occupying the interstitial space enclosed by three tri-s-triazine units in the monolayer g-C3N4 unit cell was demonstrated to be the most stable configuration in terms of adsorption energy. On the basis of these interstitial-doped monolayer g-C3N4 systems, it is found that the introduction of halogen atoms leads to various density of states (DOS) and redistribution of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). The F atom tends to occupy the valance band and HOMO due to its extremely high electronegativity. By contrast, the Cl, Br and I atoms are involved in the conduction band and LUMO. In sum, the calculation results show that the halogen-doped monolayer g-C3N4 systems have narrowed band gap, increased light absorption and reduced work function, which are conducive to high photocatalytic activity. The conclusions presented in this work indicate the availability of halogen-doped monolayer g-C3N4 with considerable photocatalytic performance.

Fabrication and enhanced visible-light photocatalytic activity of carbon self-doped TiO2 sheets with exposed {001} facets

Abstract: Novel carbon self-doped TiO2 sheets (CTS) with exposed {001} facets were synthesized by hydrothermal treatment of titanium carbide (TiC) in a HNO3-HF mixed aqueous solution. In this synthesis TiC was used as a precursor of TiO2 and a source of C, which was self-doped into the lattice of anatase sheets. The resulting CTS materials were examined as photocatalysts for degradation of methylene blue (MB) in aqueous solutions under visible light irradiation (λ > 420 nm). These materials exhibited an enhanced absorption in the whole visible-light region and an obvious red shift at the absorption edges. The first-principle density functional theory (DFT) calculations provided a further confirmation for the aforementioned red shift and for noticeable reduction of the band gap of C-doped TiO2 sheets with exposed {001} facets. The photocatalytic studies of CTS showed that these sheets exhibited much higher photocatalytic activity than that of the C-doped TiO2 nanoparticles due to the presence of exposed {001} facets. In addition, separation of CTS after photocatalytic reaction from slurry by filtration or sedimentation and their reuse is easier in comparison to conventional nanosized powder photocatalysts.