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 & Photocatalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Photocatalytic activity of Ag2MO4 (M = Cr, Mo, W) photocatalysts

Abstract: Ag-containing semiconductors have attracted significant attention because of their unique photosensitivity that provides these materials with visible-light photocatalytic activity. This study systematically investigates the correlation among the photophysicochemical performance, crystal structure, electronic structure, and photocatalytic activity and stability of three Ag-containing photocatalysts Ag2MO4 (M = Cr, Mo, W) prepared by microemulsion based on experimental and theoretical results. The results showed that the photocatalytic activity and stability of the three photocatalysts strongly depend on the light absorption performance of these photocatalysts. Ag2CrO4 had the best light absorption performance, exhibiting the highest photocatalytic activity for methylene blue degradation under visible-light irradiation that is 3.5 and 1.5 times that of Ag2MoO4 and Ag2WO4, respectively. Meanwhile, the photocatalytic stability followed the same light absorption performance order. The theoretical calculation showed that a stronger crystal field and a smaller Ag–O distance lower the conduction band bottom of Ag2CrO4 and Ag2WO4, respectively. This reduction in the conduction band caused the band gap, light-absorption, and subsequent photocatalytic activity and stability of these photocatalysts to differ. The present work contributes to deeply understand and feasibly construct Ag-containing photocatalysts with high photocatalytic activity.

Layered birnessite-type MnO2 with surface pits for enhanced catalytic formaldehyde oxidation activity

Abstract: Catalytic reaction active sites tend to be structural defects, such as edges, corners and ribs which have a low coordination number. Here, a kind of layered MnO2 (birnessite) with irregular surface pits was successfully synthesized and investigated for the catalytic oxidation of formaldehyde. The surface pits were generated by a series of chemical surface modifications. Tetrabutylammonium hydroxide (TBAOH) played a key role in generating surface pits, which entered the interlayer from the edge of acid-treated MnO2 and weakened the van der Waals force between interlayers. The steric effects of TBAOH lead to the generation of irregular surface pits. The presence of surface pits not only provided larger specific surface areas but also led to more unsaturated manganese and oxygen atoms, which promoted formaldehyde adsorption and oxygen activation. As a result, birnessite-type MnO2 with surface pits exhibited a lower apparent activation energy than the pristine one (37.6 versus 55.4 kJ mol−1) for 200 ppm of HCHO under a GHSV of 120 000 mL g−1 h−1 and ∼45% relative humidity. These findings open up a new way to generate surface pits on layered 2D materials, holding promise for designing highly efficient catalysts by creating active centers.

Preparation, microstructure and photocatalytic activity of the porous TiO2 anatase coating by sol-gel processing

Abstract: In this study the porous TiO2 anatase coatings are prepared from alkoxide solutions containing polyethylene glycol (PEG) by a dip-coating technique. The effects of PEG addition to the precursor solution on the photocatalytic activity and microstructure of the resultant coatings are studied. The larger amount and the larger molecular weight of PEG, the larger size and more pores produced in the resultant coatings on the decomposition of PEG during heat-treatment. The adsorbed hydroxyl content of such porous coatings is found to increase due to the larger size and more pores in the coatings. However, the transmittance of the coatings decreases due to the scattering by the larger size and more pores. Photocatalytic degradation experiments show that organophosphorous insecticide, dimethyl-2,2-dichlorovinyl phosphate (DDVP), was efficiently degraded in the presence of the porous TiO2 coatings by exposing the DDVP solution to sunlight. Photocatalytic degradation rate was related to the adsorbed hydroxyl content, transmittance and morphology of the resultant coatings.

Energy-Storage Properties and Electrocaloric Effect of Pb(1–3x/2)LaxZr0.85Ti0.15O3 Antiferroelectric Thick Films

Abstract: Antiferroelectric (AFE) thick (1 μm) films of Pb(1–3x/2)LaxZr0.85Ti0.15O3 (PLZT) with x = 0.08, 0.10, 0.12, and 0.14 were deposited on LaNiO3/Si (100) substrates by a sol–gel method. The dielectric properties, energy-storage performance, electrocaloric effect, and leakage current behavior were investigated in detail. With increasing La content, dielectric constant and saturated polarizations of the thick films were gradually decreased. A maximum recoverable energy-storage density of 38 J/cm3 and efficiency of 71% were achieved in the thick films with x = 0.12 at room temperature. A large reversible adiabatic temperature change of ΔT = 25.0 °C was presented in the thick films with x = 0.08 at 127 °C at 990 kV/cm. Moreover, all the samples had a lower leakage current density below 10–6 A/cm2 at room temperature. These results indicated that the PLZT AFE thick films could be a potential candidate for applications in high energy-storage density capacitors and cooling devices.