Effect of H2 gas as a reductant on photoreduction of CO2 over a Ga2O3 photocatalyst

Ga(2)O(3) was used as a photocatalyst for the photoreduction of CO(2) in the presence of H(2) as a reductant; in this process CO gas was selectively produced at room temperature and ambient pressure. The optimum conversion of CO(2) was approximately 3% using beta-Ga(2)O(3) calcined at 1073 K for 6 h. The formation of CO depended on the amounts of H(2) and CO(2) introduced into the system. The photoreduction of CO(2) on Ga(2)O(3) involves two chemisorbed species-H(2) and CO(2). This implies that the photocatalytic reaction would proceed on the basis of the typical Langmuir-Hinshelwood mechanism. (C) 2008 Elsevier B.V. All rights reserved.