A Bifunctional CdS/MoO2/MoS2 Catalyst Enhances Photocatalytic H2 Evolution and Pyruvic Acid Synthesis

Abstract 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 2 /MoS 2 hollow spheres for hydrogen evolution coupled with selective pyruvic acid (PA) production from lactic acid (LA) oxidation. MoS 2 and MoO 2 are simultaneously obtained from the conversion of CdMoO 4 in one step. In a photocatalytic process, the MoS 2 and MoO 2 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 3 )−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.