Boosting photocatalytic CO reduction Schottky junction with ZnCr layered double hydroxide nanoflakes aggregated on 2D TiCT cocatalyst.

Designing efficient photocatalysts is vital for the photoreduction of CO to produce solar fuels, helping to alleviate issues of fossil fuel depletion and global warming. In this work, a novel ZnCr-LDH/TiCT Schottky junction is successfully synthesized using an coprecipitation method. ZnCr-LDH nanoflakes collectively grow on the surface of TiCT MXene nanosheets. When using TiCT 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/TiCT results in significant improvement in the performance of photocatalytic CO reduction under simulated solar irradiation. The optimized sample ZCTC25 has the highest photocatalytic CO reduction rates of 122.45 μmol g CO and 19.95 μmol g CH (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.