A Bifunctional CdS/MoO /MoS Catalyst Enhances Photocatalytic H Evolution and Pyruvic Acid Synthesis.

The best use of photogenerated electrons and holes is crucial to boosting photocatalytic activity. Herein, a bifunctional dual-cocatalyst-modified photocatalyst is constructed based on CdS/MoO /MoS hollow spheres for hydrogen evolution coupled with selective pyruvic acid (PA) production from lactic acid (LA) oxidation. MoS and MoO are simultaneously obtained from the conversion of CdMoO in one step. In a photocatalytic process, the MoS and MoO function as the reduction and oxidation centers on which photogenerated electrons and holes accumulate and are used for hydrogen evolution reaction (HER) and PA synthesis, respectively. By monitoring the intermediates, a two-step single-electron route for PA production is proposed, initiated by the cleavage of the α-C(sp )-H bond in the LA. The conversion of LA and the selectivity of PA can reach ca. 29 % and 95 % after a five-hour reaction, respectively.