Molten Salt Synthesis of Ti3C2/Cu Cocatalyst for Enhanced TiO2 Photocatalytic CO2 Reduction

Abstract Photocatalytic reduction of CO 2 is considered as a crucial pathway towards achieving sustainable energy and environmental goals. Nonetheless, attaining efficient CO 2 conversion poses significant challenges, primarily due to the slow dynamics of charge carriers and the high activation energy required to break C=O bonds. In this study, a novel strategy involving Lewis acid molten salt etching is investigated to engineer a titanium oxide (TiO 2 )‐based photocatalysts with dual electron transfer channels (i. e., Ti 3 C 2 /Cu), which targets the photoreduction of CO 2 to CO and CH 4 . Thanks to the dual electron transfer channels presented in the cocatalysts (Ti 3 C 2 /Cu), in conjunction with the numerous heterogeneous interfaces between TiO 2 and the Ti 3 C 2 /Cu cocatalysts, this hybrid catalyst not only reduces charge transfer resistance but also accelerates the dynamics of photogenerated charge carriers. Consequently, the TiO 2 /Ti 3 C 2 /Cu hybrid catalyst demonstrates an exceptional photocatalytic CO 2 reduction rate of 13.67 μmol g −1 h −1 , with a total utilized photoelectron number (UPN) of 102.34 μmol g −1 h −1 . which is 3.99‐fold higher than that of unmodified TiO 2 . This research provides a new approach for the preparation of dual cocatalysts through a one‐step molten salt synthesis process.