Boosting photocatalytic CO 2 reduction via Schottky junction with ZnCr layered double hydroxide nanoflakes aggregated on 2D Ti 3 C 2 T x cocatalyst.

Designing efficient photocatalysts is vital for the photoreduction of CO 2 to produce solar fuels, helping to alleviate issues of fossil fuel depletion and global warming. In this work, a novel ZnCr-LDH/Ti 3 C 2 T x Schottky junction is successfully synthesized using an in situ coprecipitation method. ZnCr-LDH nanoflakes collectively grow on the surface of Ti 3 C 2 T x MXene nanosheets. When using Ti 3 C 2 T x MXene as a cocatalyst in the prepared heterojunction, the light absorption intensity, photo-induced electron separation and migration efficiency increase. As a result, the composite ZnCr-LDH/Ti 3 C 2 T x results in significant improvement in the performance of photocatalytic CO 2 reduction under simulated solar irradiation. The optimized sample ZCTC25 has the highest photocatalytic CO 2 reduction rates of 122.45 μmol g -1 CO and 19.95 μmol g -1 CH 4 (after 6 h of irradiation). These values are approximately 2.65 times higher than those of pristine ZnCr-LDH. The product selectivity towards CO is 86%. This work provides a new method for the construction of novel 2D semiconductor photocatalysts and enriches the application of an unusual type of layered double hydroxides in the photoreduction of CO 2 .