Synergistic CO2 reduction and tetracycline degradation by CuInZnS-Ti3C2Tx in one photoredox cycle

Optimizing photocatalytic CO2 reduction with simultaneous pollutant degradation is highly desired. However, the photocatalytic efficiency is restricted by the unmatched redox ability, high carriers’ recombination rate, and lack of reactive sites of the present photocatalysts. Herein, the CuInZnS-Ti3C2Tx hybrid with matched redox ability and suitable CO2 adsorption property was rationally synthesized. The nucleation and growth process of CuInZnS was interfered by the addition of Ti3C2Tx with a negative charge, resulting in thinner nanosheets and richer reactive sites. Besides, the Schottky heterojunction built in the hybrid simultaneously improved the photoexcited charge transfer property, sunlight absorption range, and CO2 adsorption ability. Consequently, upon exposure to sunlight, CuInZnS-Ti3C2Tx exhibited an efficient photocatalytic CO2 reduction performance (10.2 µmol·h−1·g−1) with synergetic tetracycline degradation, obviously higher than that of pure CuInZnS. Based on the combination of theoretical calculation and experimental characterization, the photocatalytic mechanism was investigated comprehensively. This work offers a reference for the remission of worldwide energy shortage and environmental pollution problems.