Synthesis of ZnO/Ti2C composites by electrostatic self-assembly for the photocatalytic degradation of methylene blue

Two-dimensional (2D) zinc oxide (ZnO) has great potential in the field of dye photocatalytic degradation. However, the photocatalytic activity is always unsatisfactory because of its small specific surface area and high carrier recombination rate. In this study, peony flower-like ZnO/Ti2C (2 wt% ZnO/Ti2C) composites were successfully prepared by simple electrostatic self-assembly method with morphology design and content adjustment of MXene Ti2C. The prepared materials displayed excellent photocatalytic degradation activity and photocorrosion resistance of methylene blue (MB) dye. After 120 min UV irradiation, the degradation rate reached 99.16%, and the apparent rate constant k was 0.03926 min(-1), which was 14.76 times higher than that of pure ZnO. The photocatalytic activity almost did not decrease after 4 cycles. The introduction of Ti2C promoted the formation of tightly interfacial coupling between ZnO and Ti2C, which shortens the path of carrier transfer and promoted the direct transfer of photogenerated electrons from the valence band of ZnO to Ti2C. The specific surface area of hybrids showed distinct enlargement simultaneously, which was a benefit for enhancing the UV absorption capacity of ZnO/Ti2C composites. Meaningfully, this study provides a feasible design strategy for improving the degradation performance of 2D photocatalysts, which can provide a technical proposal for the modification design of other photocatalysts.

Automated summary

In this study, peony flower-like ZnO/Ti2C composites were prepared and demonstrated excellent photocatalytic degradation activity and photocorrosion resistance. The introduction of Ti2C enhanced carrier transfer efficiency and increased the UV absorption capacity of the composites.