Photocatalytic methane conversion coupled with hydrogen evolution from water over Pd/TiO2

Abstract

The pursuit for efficient conversion of methane under ambient conditions remains a challenge, and the photocatalytic splitting of water into H₂ is a hot research topic since H₂ is considered to be the cleanest energy. Here, the two reactions are introduced into one photocatalytic system, which achieves the simultaneous utilization of photo-induced electrons and holes. The mechanism results demonstrate that photo-induced electrons contribute to the production of H₂, while holes contribute to the conversion of CH₄. This work provides a new strategy for photocatalytic reactions, and provides considerable quantum efficiencies for electrons of 2.83% (without a sacrificial agent) and holes of 2.76%. In view of the closed values of the quantum efficiencies for the two original photo-induced species, it is believed that the separated electrons and holes are more effectively utilized.