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.