Towards the improvement of methane production in CO2 photoreduction using Bi2WO6/TiO2 heterostructures

Russelite bismuth tungstate (Bi2WO6) has been widely reported for the photocatalytic degradation and miner-alization of a myriad of pollutants as well as organic compounds. These materials present perovskite-like structure with hierarchical morphologies, which confers excellent optoelectronic properties as potentials can-didates for photocatalytic solar fuels production. Here, we propose the development of Bi2WO6/TiO2 hetero-junctions for CO2 photoreduction, as a promising solution to produce fuels, alleviate global warming and tackle fossil fuel shortage. Our results show an improvement of the photocatalytic activity of the heterojunctions compared to the pristine semiconductors. Near Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) experiments reveals a preferential CO2 adsorption over TiO2. On the other hand, transient absorption spec-troscopy measurements show that the charge transfer pathway in Bi2WO6/TiO2 hybrids leads to longer-lived photogenerated carriers in spatially separated redox active sites, which favor the reduction of CO2 into highly electron demanding fuels and chemicals, such as CH4 and C2H6.

Automated summary

Russelite bismuth tungstate (Bi2WO6) is a material with excellent optoelectronic properties, which can be used for photocatalytic degradation and mineralization of pollutants and organic compounds. This study proposes the development of Bi2WO6/TiO2 heterojunctions for CO2 photoreduction, showing potential for producing fuels, alleviating global warming, and addressing fossil fuel shortage.