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.

Conjugated polymers for visible-light-driven photocatalysis

Abstract: Conjugated polymers have recently been under active investigation as promising alternatives to traditional inorganic semiconductors for photocatalysis. This is due to their unique advantages of low cost, high chemical stability, and molecularly tunable optoelectronic properties. This critical review summarizes the recent advancements in π-conjugated polymers for visible-light-driven photocatalytic applications including water splitting, CO2 reduction, organic transformation and degradation of organic dyes. Special emphasis is placed on how the changes in the polymer structure could influence their physicochemical properties and photocatalytic activities. This structure–activity relationship analysis should guide rational molecular design of conjugated polymers for improved photocatalytic activity.

Decomposition of Environmentally Persistent Perfluorooctanoic Acid in Water by Photochemical Approaches

Abstract: The decomposition of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in water by UV−visible light irradiation, by H2O2 with UV−visible light irradiation, and by a tungstic heteropolyacid photocatalyst was examined to develop a technique to counteract stationary sources of PFOA. Direct photolysis proceeded slowly to produce CO2, F-, and short-chain perfluorocarboxylic acids. Compared to the direct photolysis, H2O2 was less effective in PFOA decomposition. On the other hand, the heteropolyacid photocatalyst led to efficient PFOA decomposition and the production of F- ions and CO2. The photocatalyst also suppressed the accumulation of short-chain perfluorocarboxylic acids in the reaction solution. PFOA in the concentrations of 0.34−3.35 mM, typical of those in wastewaters after an emulsifying process in fluoropolymer manufacture, was completely decomposed by the catalyst within 24 h of irradiation from a 200-W xenon−mercury lamp, with no accompanying catalyst degradation, permitting the catalyst...

Fabrication of a novel p–n heterojunction photocatalyst n-BiVO4@p-MoS2 with core–shell structure and its excellent visible-light photocatalytic reduction and oxidation activities

Abstract: The novel p–n heterojunction photocatalyst n-BiVO4@p-MoS2 with core–shell structure was successfully fabricated for the first time through a facile in-situ hydrothermal method, in which MoS2 shell thickness was easily tuned by varying the concentration of MoS2 precursor in the solution. The photocatalytic performances of samples were systematically investigated via the photocatalytic reduction of Cr6+ and oxidation of crystal violet (CV) under visible-light irradiation. The BiVO4@MoS2 samples exhibited excellent photocatalytic performance, among which, the BiVO4@MoS2 (10 wt%) sample with MoS2 shell 300 nm thickness, showed the highest photoreduction and photooxidation activities. The enhanced photocatalytic activities could be attributed to the suppression of charge recombination, the high specific surface area and strong adsorption ability toward the pollutant molecule, and the enhanced or tunable light absorption of BiVO4@MoS2. Especially, the core–shell structure geometry also increases the contact area between BiVO4 and MoS2, which facilitates the charge transfer at the BiVO4/MoS2 interface. The photocatalytic mechanism of BiVO4@MoS2 for reduction of Cr6+ and oxidation of CV was discussed in detail. Moreover, 12 photocatalytic degradation intermediates and products of CV were also identified by the gas chromatography–mass spectrometer (GC–MS).

Artificial Z-scheme constructed with a supramolecular metal complex and semiconductor for the photocatalytic reduction of CO2.

Abstract: A hybrid for the visible-light-driven photocatalytic reduction of CO2 using methanol as a reducing agent was developed by combining two different types of photocatalysts: a Ru(II) dinuclear complex (RuBLRu′) used for CO2 reduction is adsorbed onto Ag-loaded TaON (Ag/TaON) for methanol oxidation. Isotope experiments clearly showed that this hybrid photocatalyst mainly produced HCOOH (TN = 41 for 9 h irradiation) from CO2 and HCHO from methanol. Therefore, it converted light energy into chemical energy (ΔG° = +83.0 kJ/mol). Photocatalytic reaction proceeds by the stepwise excitation of Ag/TaON and the Ru dinuclear complex on Ag/TaON, similar to the photosynthesis Z-scheme.