Anchoring MnWO 4 Nanorods on LaTiO 2 N Nanoplates for Boosted Visible Light-Driven Overall CO 2 Reduction.

The photocatalytic conversion of CO 2 into hydrocarbon fuel holds immense potential for achieving a carbon closed loop and carbon neutrality. Developing efficient photocatalysts plays a pivotal role in enabling the widespread application of photocatalytic CO 2 reduction on a large scale. Herein, a novel S-scheme MnWO 4 /LaTiO 2 N heterojunction composite is successfully synthesized by a hydrothermal method. This composite catalyst demonstrates excellent photocatalytic activity in the reduction of CO 2 to CO and CH 4 using water molecules as electron donors under visible light irradiation, and the optimized 30% MnWO 4 /LaTiO 2 N composite displays significantly enhanced CO and CH 4 yields of 3.94 and 0.81 μmol g -1 h -1 , respectively, and the corresponding utilized photoelectron number reaches 14.7 μmol g -1 h -1 , which is approximately 7.7 and 12.9 times that of LaTiO 2 N and MnWO 4 . The enhancement in photocatalytic activity of the composites can be ascribed to the construction of an S-scheme heterojunction, which exhibits improved charge transfer dynamics, retains the strongest redox capacity, and effectively suppresses back reactions. In situ Fourier-transform infrared imaging provides evidence, to a certain extent, for the existence of a temporal gradient order in the generation of multiple products during the photocatalytic reduction of CO 2 .