One-pot hydrothermal preparation of PbO-decorated brookite/anatase TiO2 composites with remarkably enhanced CO2 photoreduction activity

Abstract

Converting CO2 into solar fuels can deliver dual benefits to reducing the atmospheric CO2 levels and mitigating the energy shortage. Herein, PbO-decorated TiO2 composites (PbO/TiO2) are synthesized by a one-pot hydrothermal method. It is found that Pb2+ ions cause the product transforming from brookite TiO2quasi nanocubes (pristine TiO2) into heterophase junctions composed by brookite nanorods and anatase nanoparticles. By using as photocatalyst, 1.0% PbO/TiO2 delivers the best CH4/CO production activities of 53.21/5.99 μmol g−1 h−1 with an overall photoactivity of 437.7 μmol g−1 h−1. It is 33.2 times of the pristine TiO2 with an overall photoactivity of 13.2 μmol g−1 h−1. Further investigations demonstrate that the heterophase junctions can effectively retard the charge recombination, and the PbO promotes the CO2 adsorption/activation processes, and therefore causing the remarkably enhanced activity. The present work opens up an ideal synthetic route for metal oxide-assistant TiO2 heterophase junctions with highly photoactive CO2 conversion.