Photocatalysis

About: Photocatalysis is a research topic. Over the lifetime, 67088 publications have been published within this topic receiving 2145233 citations. The topic is also known as: photocatalyst.

Ag-ZnO catalysts for UV-photodegradation of methylene blue

Abstract: High surface area Ag-ZnO catalysts have been made by flame spray pyrolysis (FSP) and characterized by X-ray diffraction (XRD), nitrogen adsorption, UV–vis spectroscopy and electron microscopy (SEM and transmission electron microscopy (TEM)) combined with energy dispersive X-ray spectroscopy (EDXS) for elemental mapping. Silver metal clusters deposited directly on ZnO nanocrystals were obtained from this process. The Ag loading (1–5 at.%) controlled the Ag cluster size from 5 to 25 nm but did not influence the ZnO crystal size. Photodegradation of 10 ppm methylene blue (MB) solution was used to evaluate the performance of these FSP-made Ag-ZnO and was compared to wet-made Ag-ZnO and reference titania photocatalysts. The rate of photodegradation was optimal for Ag loading around 3 at.%. The best photocatalytic performance was exhibited by flame-made Ag-ZnO produced at the longest high-temperature residence times having high crystallinity as determined by XRD and UV–vis.

WO3 nanorods/graphene nanocomposites for high-efficiency visible-light-driven photocatalysis and NO2 gas sensing

Abstract: One-dimensional (1-D) nanostructures are of great importance due to their superior charge transport properties. Anchoring 1-D semiconductor nanomaterials on graphene offers potential advantages in photoelectrochemical and sensing applications. This paper presents a systematic investigation on the incorporation of WO3 nanorods and graphene for high-efficiency visible-light-driven photocatalysis and NO2 gas sensing. This novel composite shows remarkably enhanced performance compared to pure WO3 nanorods for these applications. The high photocatalytic activity of the WO3/graphene nanocomposite is found to be related to the increased adsorption toward chemical species, enhanced light absorption and efficient charge separation and transfer. Meanwhile, the improved conductivity, specific electron transfer and increased gas adsorption also contribute to their superior sensitivity and selectivity to NO2 gas.

Layered‐Double‐Hydroxide Nanosheets as Efficient Visible‐Light‐Driven Photocatalysts for Dinitrogen Fixation

Abstract: Semiconductor photocatalysis attracts widespread interest in water splitting, CO2 reduction, and N2 fixation. N2 reduction to NH3 is essential to the chemical industry and to the Earth's nitrogen cycle. Industrially, NH3 is synthesized by the Haber-Bosch process under extreme conditions (400-500 °C, 200-250 bar), stimulating research into the development of sustainable technologies for NH3 production. Herein, this study demonstrates that ultrathin layered-double-hydroxide (LDH) photocatalysts, in particular CuCr-LDH nanosheets, possess remarkable photocatalytic activity for the photoreduction of N2 to NH3 in water at 25 °C under visible-light irradiation. The excellent activity can be attributed to the severely distorted structure and compressive strain in the LDH nanosheets, which significantly enhances N2 chemisorption and thereby promotes NH3 formation.

Visible light photodegradation of phenol on MWNT-TiO2 composite catalysts prepared by a modified sol–gel method

Abstract: Multi-walled carbon nanotubes (MWNT) and TiO2 composite catalysts were prepared by a modified sol–gel method. The nanoscaled composite materials were extensively characterized by TG, N2 adsorption-desorption isotherm, XRD, SEM, EDX, TEM and UV–vis spectra. The photocatalytic degradation of phenol was performed under visible light irradiation on these catalysts. An optimum of synergetic effect on photocatalytic activity was observed for a weight ratio MWNT/TiO2 equal to 20% with an increase in the first-order rate constant by a factor of 4.1. The synergetic effect, induced by a strong interphase interaction between MWNT and TiO2, was discussed in terms of different roles played by MWNT in the composite catalysts.