Construction of 2D/2D Ti3C2Tx MXene/CdS heterojunction with photothermal effect for efficient photocatalytic hydrogen production

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic reactions. Constructing photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor materials. Herein, a novel stable Ti3C2Tx MXene/CdS heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional (2D) CdS nanosheets on 2D MXene interface via a solvothermal method. The exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocatalytic hydrogen evolution capability upon the heterogeneous catalyst. The unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers, enhancing the photocatalytic performance of the catalyst. Moreover, the composite catalyst exhibits a significantly higher surface temperature of 80.4 °C under visible light irradiation at an intensity of 0.1 W/cm2, which is 1.84 times higher than that of CdS. Under irradiation of visible and near infrared light, the composite catalyst with photothermal effect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g-1 h-1, which is 7.2 times higher than that of CdS catalyst. This study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.