Hydrothermal growth of ZnCdS/TiO2 nanoparticles on the surface of the Ti3C2 MXene sheet to enhance photocatalytic performance under visible light

ZnCdS/TiO2/Na-MXene composites were prepared by a hydrothermal process to obtain an excellent photocatalyst with photo-corrosion resistant property. Under hydrothermal conditions, the surface of Ti3C2 MXene was wrapped by Na+ and ZnCdS nanoparticles, which slowed down the further oxidation of Ti3C2 MXene into TiO2 and improved the utilization rate of MXene. The adsorption capacity of an optimal ZnCdS/TiO2/Na-MXene composite to methylene blue reached 299.68 ​mg/g, confirming a higher MXene content was important for photocatalytic degradation of an organic dye. The basal distance of the MXene layers increased from 10.59 ​Å to 15.21 ​Å due to the intercalation of ZnCdS, which could facilitate the transportation and adsorption of organic pollutant in ZnCdS/TiO2/Na-MXene. The total removal efficiency was 9.3 times that of ZnCdS in 120 ​min. When the composites were used for photocatalytic hydrogen production, a relatively higher ZnCdS content was necessary. The hydrogen conversion efficiency of an optimal ZnCdS/TiO2/Na-MXene composite under visible light irradiation reached 8436.58 ​μmol·g−1·h−1, which was 3.3 times that of ZnCdS. The ZnCdS/TiO2/Na-MXene composites showed excellent and stable photocatalytic activity in recycling experiments, confirming their excellent photo-corrosion property. These ZnCdS/TiO2/Na-MXene composites showed great potential in the application of photocatalytic degradation and hydrogen production, and provided a new way to reduce the oxidation process of Ti3C2 MXene.