Co-embedding oxygen vacancy and copper particles into titanium-based oxides (TiO2, BaTiO3, and SrTiO3) nanoassembly for enhanced CO2 photoreduction through surface/interface synergy

Photocatalytic CO 2 reduction into valuable fuel and chemical production has been regarded as a prospective strategy for tackling with the issues of the increasing of greenhouse gases and shortage of sustainable energy. A composite photocatalysis system employing a semiconductor enriched with oxygen vacancy and coupled with metallic cocatalyst can facilitate charge separation and transfer electrons . In this work, mesoporous TiO 2 and titanium-based perovskite oxides (BaTiO 3 and SrTiO 3 ) nanoparticle assembly incorporated with abundant oxygen vacancy and copper particles have been successfully synthesized for CO 2 photoreduction . As an example, the TiO 2 decorated with different amounts of Cu particles has an impact on photocatalytic CO 2 reduction into CH 4 and CO. Particularly, the optimal TiO 2 /Cu-0.1 exhibits nearly 13.5 times higher CH 4 yield (22.27 μmol g −1  h −1 ) than that of pristine TiO 2 (1.65 μmol g −1  h −1 ). The as-obtained BaTiO 3 /Cu-0.1 and SrTiO 3 /Cu-0.1 also show enhanced CH 4 yields towards photocatalytic CO 2 reduction compared with pristine ones. Based on the temperature programmed desorption (TPD) and photo/electrochemical measurements, the co-embedding of Cu particles and abundant oxygen vacancy into the titanium-based oxides could promote CO 2 adsorption capacity as well as separation and transfer of photoinduced electron-hole pairs, and finally result in efficient CO 2 photoreduction upon the TiO 2 /Cu, SrTiO 3 /Cu, and BaTiO 3 /Cu composites.