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.

Improving the photocatalytic hydrogen production of Ag/g-C3N4 nanocomposites by dye-sensitization under visible light irradiation

Abstract: Ag nanoparticles were deposited on the surface of g-C3N4 by a chemical reduction method to increase visible-light absorption via the localized surface plasmon resonance effect, resulting in the reduced recombination of photo-generated electron–holes and enhanced photocatalytic activity. The Ag/g-C3N4 composite with a Ag loading of 3 wt% has the optimum photoactivity that is almost 3.6 and 3.4 times higher than pure g-C3N4 and the same photocatalysis system which has been reported, respectively. Fluorescein was introduced as a photosensitizer and H2 evolution soared to 2014.20 μmol g−1 h−1 and the rate is even about 4.8 times higher than that of the 3 wt% Ag/g-C3N4 composite. The chemical structure, composites, morphologies and optical properties of the obtained products are well-characterized by XRD, FTIR, TEM, EDS, XPS and UV-Vis DRS. Meanwhile, the photocatalyst exhibits high stability and reusability.

Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

Abstract: Photocatalysis has not found widespread industrial adoption, in spite of decades of active research, because the challenges associated with catalyst illumination and turnover outweigh the touted advantages of replacing heat with light. A demonstration that light can control product selectivity in complex chemical reactions could prove to be transformative. Here, we show how the recently demonstrated plasmonic behaviour of rhodium nanoparticles profoundly improves their already excellent catalytic properties by simultaneously reducing the activation energy and selectively producing a desired but kinetically unfavourable product for the important carbon dioxide hydrogenation reaction. Methane is almost exclusively produced when rhodium nanoparticles are mildly illuminated as hot electrons are injected into the anti-bonding orbital of a critical intermediate, while carbon monoxide and methane are equally produced without illumination. The reduced activation energy and super-linear dependence on light intensity cause the unheated photocatalytic methane production rate to exceed the thermocatalytic rate at 350 °C. Atmospheric CO2 can be transformed into valuable hydrocarbons by reaction with H2, but CO is the favoured kinetic product. Here, Liu and co-workers show that plasmonic rhodium nanoparticles not only reduce the activation energy for CO2hydrogenation, but also photo-selectively produce methane.

Enhancement of photocatalytic activity of Bi2WO6 hybridized with graphite-like C3N4

Abstract: Bi2WO6 photocatalyst was hybridized by graphite-like C3N4via facile chemisorption. After hybridization with C3N4, the photocatalytic activity of Bi2WO6 was obviously enhanced. A C3N4/Bi2WO6 photocatalyst hybridized with monolayer C3N4 exhibited the highest photocatalytic activity which was 68.9% higher than that of pure Bi2WO6. The enhanced photocatalytic activity of the C3N4/Bi2WO6 photocatalysts could be attributed to the synergetic effect between C3N4 and Bi2WO6. The photogenerated holes on the valence band of Bi2WO6 could transfer to the highest occupied molecular orbital of C3N4via the well developed interface, causing rapid photoinduced charge separation and enhancing the photocatalytic activity.