Towards the improvement of methane production in CO2 photoreduction using Bi2WO6/TiO2 heterostructures
Laura Collado, Miguel Gomez‐Mendoza, Miguel García‐Tecedor, F. Palacio, Anna Reynal, James R. Durrant, David P. Serrano, Víctor A. de la Peña O’Shea
Abstract
Russelite bismuth tungstate (Bi 2 WO 6 ) has been widely reported for the photocatalytic degradation and mineralization 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 candidates for photocatalytic solar fuels production. Here, we propose the development of Bi 2 WO 6 /TiO 2 heterojunctions for CO 2 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 CO 2 adsorption over TiO 2 . On the other hand, transient absorption spectroscopy measurements show that the charge transfer pathway in Bi 2 WO 6 /TiO 2 hybrids leads to longer-lived photogenerated carriers in spatially separated redox active sites, which favor the reduction of CO 2 into highly electron demanding fuels and chemicals, such as CH 4 and C 2 H 6 .