Understanding rich oxygen vacant hollow CeO@MoSe heterojunction for accelerating photocatalytic CO reduction.

Solar-driven CO reduction into gas fuels is desirable for a sustainable carbon cycle. To improve the photocatalytic activity of CORR, the unique rich oxygen (Vo) vacant hollow CeO@MoSe is designed. The introduction of Vo is conducive to the capture of electrons by CO and promotes the process of photocatalytic CORR. The heterojunction formed by introducing the narrow band gap semiconductor MoSe increases the absorption range of visible light and improves the separation efficiency of photogenerated carriers. The hollow structure improves the CO adsorption capacity and improves the use of light effect. Therefore, the prepared H-Vo-CeO@49.7 wt% MoSe exhibits enhanced photocatalytic activity for CORR. The yield of CH and CO is 10.2 µmol and 33.2 µmol in 4 h. Moreover, the photocatalytic mechanism is discussed through DFT and in-situ DRIFTS. This work provides new insights to the role of Vo in active CO photoconversion and exploits an important application of CO reduction.