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

Photocatalytic reduction of CO2 is considered as a crucial pathway towards achieving sustainable energy and environmental goals. Nonetheless, attaining efficient CO2 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 (TiO2)‐based photocatalysts with dual electron transfer channels (i. e., Ti3C2/Cu), which targets the photoreduction of CO2 to CO and CH4. Thanks to the dual electron transfer channels presented in the cocatalysts (Ti3C2/Cu), in conjunction with the numerous heterogeneous interfaces between TiO2 and the Ti3C2/Cu cocatalysts, this hybrid catalyst not only reduces charge transfer resistance but also accelerates the dynamics of photogenerated charge carriers. Consequently, the TiO2/Ti3C2/Cu hybrid catalyst demonstrates an exceptional photocatalytic CO2 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 TiO2. This research provides a new approach for the preparation of dual cocatalysts through a one‐step molten salt synthesis process. We propose a Lewis acid molten salt etching strategy to fabricate titanium dioxide‐based photocatalysts, which incorporate dual electron transfer channels (Ti3C2/Cu) and abundant heterogeneous interfaces, specifically tailored for enhanced photocatalytic CO2 reduction. This innovative design yields a CO2 reduction rate that surpasses that of bare TiO2 by a factor of 3.99, highlighting its substantial performance improvement.