Co-embedding oxygen vacancy and copper particles into titanium-based oxides (TiO, BaTiO, and SrTiO) nanoassembly for enhanced CO photoreduction through surface/interface synergy.

Photocatalytic CO 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 and titanium-based perovskite oxides (BaTiO and SrTiO) nanoparticle assembly incorporated with abundant oxygen vacancy and copper particles have been successfully synthesized for CO photoreduction. As an example, the TiO decorated with different amounts of Cu particles has an impact on photocatalytic CO reduction into CH and CO. Particularly, the optimal TiO/Cu-0.1 exhibits nearly 13.5 times higher CH yield (22.27 μmol g h) than that of pristine TiO (1.65 μmol g h). The as-obtained BaTiO/Cu-0.1 and SrTiO/Cu-0.1 also show enhanced CH yields towards photocatalytic CO 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 adsorption capacity as well as separation and transfer of photoinduced electron-hole pairs, and finally result in efficient CO photoreduction upon the TiO/Cu, SrTiO/Cu, and BaTiO/Cu composites.