Deposition of CeO2 on TiO2 nanorods electrode by dielectric barrier discharge plasma to enhance the photoelectrochemical performance in high chloride salt system

CQDs improved the photoelectrocatalytic performance of plasma assembled WO3/TiO2-NRs for bisphenol A degradation

Carbon quantum dots (CQDs) have been supported on WO₃/TiO₂-NRs using a hydrothermal method and a novel CQDs/WO₃/TiO₂-NRs composite formed via dielectric barrier discharge. The composite electrodes were characterized using morphology, structural, optical and electrochemical analysis. The CQDs were successfully prepared on the composite electrode with the highest photocurrent density reaching 2.51 mA·cm^-2 under UV-visible light irradiation (100 mW·cm^-2) and an applied voltage of 0.6 V vs. Ag/AgCl. The CQDs/WO₃/TiO₂-NRs electrode exhibited a good degradation effect toward bisphenol A (BPA) (75.66 %) combined with the production of hydrogen (0.89 mmol) in Na₂SO₄ system after 2 h of the photoelectrocatalytic (PEC) reaction and the BPA degradation rate reached 100 % after 7 min of reaction in both simulated and real seawater. The CQDs/WO₃/TiO₂-NRs exhibited excellent stability and efficient PEC performance in which the CQDs acted as electron reservoirs to capture and promote charge separation. Our analysis of intermediates of BPA degradation indicated the possible degradation pathways that mainly formed BPA polymers in the Na₂SO₄ system or chlorinated compounds in the high chloride salt system.

A Novel Photocatalytic Functional Coating Applied to the Degradation of Xylene in Coating Solvents under Solar Irradiation

A novel photocatalytic functional coating was prepared with g-C₃N₄/TiO₂ composites as the photocatalytic active component modified by dielectric barrier discharge (DBD), and it showed an efficient catalytic performance under solar light irradiation. The degradation of xylene released from fluorocarbon coating solvents by the g-C₃N₄/TiO₂ composite coatings was investigated under simulated solar irradiation. The degradation efficiency of the coating mixed with DBD-modified 10%-g-C₃N₄/TiO₂ showed a stable, long-lasting, and significantly higher activity compared to the coatings mixed with the unmodified catalyst. Ninety-eight percent of the xylene released from fluorocarbon coating solvents was successfully removed under solar light irradiation in 2 h. The properties of the catalyst samples before and after modification were evaluated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) spectroscopy, X-ray photoelectron spectroscopy (XPS), and other characterization techniques. The results suggested that DBD-modified g-C₃N₄/TiO₂ showed an improved capture ability and utilization efficiency of solar light with reduced band gap and lower complexation rate of electron-hole pairs. The prepared photocatalytic coating offers an environmentally friendly approach to purify the volatile organic compounds (VOCs) released from solvent-based coatings.

Combining non-thermal plasma technology with photocatalysis: a critical review

Due to the excellent application prospects in the fields of new energy generation and environmental remediation, photocatalysis technology has attracted the increasing attention of researchers. Although significant progress has been made in the past decades, the practical application of this technology is still restricted by the moderate catalytic efficiency. To improve the performance of catalysts, new methods are extremely required for the controllable synthesis of high-efficiency catalysts. To further comprehend the relationship between material structure and catalytic activity, the surface active sites of catalysts should be regulated at the atomic and molecular levels. As the fourth state of matter, plasma can generate diverse active species with low energy consumption. As a subset of plasmas, non-thermal plasma (NTP), defined by the great temperature difference between ions (near room temperature) and electrons (usually hotter than 2 orders of magnitude), contributes to the rapid synthesis of functional nanomaterials under relatively mild conditions. Furthermore, NTP has been widely used for the surface modification of materials. Therefore, the combination of NTP and photocatalysis is expected to provide an ideal approach to synthesize high-performance catalysts and precisely customize their surface structures, which is becoming a new direction in the field of catalysis research. This paper fundamentally reviews the progress in the combination of NTP with photocatalysis for versatile applications. Beginning with the principles of photocatalysis and plasma technology, the application of NTP for catalyst synthesis, the plasma-assisted modification of surface actives sites, and the impact of plasma-involved processes on the catalytic performance are discussed, which will provide useful insights into the performance enhancement of catalysts via plasma-assisted processes.