In-situ growth of Cs2AgBiBr6 perovskite nanocrystals on Ti3C2Tx MXene nanosheets for enhanced photocatalytic activity

Photocatalytic degradation of organic dyes is an efficient, safe and environmentally-friendly technique for improving environmental purification. Exploring high-quality and low-cost photocatalysts for photocatalytic degradation with enhanced light harvesting capability and efficient charge separation and transport remains a challenge. Herein, we utilize the two-dimensional (2D) MXene, Ti(3)C(2)Tx nanosheets as a high efficiency co-catalyst to construct the Cs2AgBiBr6/Ti3C2Tx Schottky heterostructure by in-situ growth of Cs2AgBiBr6 perov-skite NCs on Ti(3)C(2)Tx nanosheets via thermal injection method. The optimized Cs2AgBiBr6/Ti3C2Tx nano-composites show a substantially enhanced organic dye degradation rate, which is similar to 4.7 times higher than that of the pristine Cs2AgBiBr6 NCs. Such outstanding photocatalytic activity of Cs2AgBiBr6/Ti3C2Tx nanocomposites stems from the strong interaction between Cs2AgBiBr6 NCs and highly conductive 2D Ti(3)C(2)Tx nanosheets, a large interface contact area, and the favorable Fermi level alignment, which significantly promote the charge transfer and separation efficiency while suppressing the electron-hole recombination. More importantly, the Cs2AgBiBr6/ MXenes-based photocatalysts exhibit good repeatability and long-term stability. It is demonstrated that this work will guide the construction of high-efficiency and stable photocatalytic materials for environmental purification.

Automated summary

In this study, two-dimensional MXene nanosheets were used as high-efficiency co-catalysts to construct Cs2AgBiBr6/Ti3C2Tx Schottky heterostructures by in-situ growth of Cs2AgBiBr6 perovskite nanocrystals on Ti(3)C(2)Tx nanosheets via thermal injection method. The optimized Cs2AgBiBr6/Ti3C2Tx nanocomposites showed significantly enhanced organic dye degradation rate, about 4.7 times higher than that of the pristine Cs2AgBiBr6 nanocrystals. The outstanding photocatalytic activity of Cs2AgBiBr6/Ti3C2Tx nanocomposites was attributed to the strong interaction between Cs2AgBiBr6 nanocrystals and highly conductive 2D Ti(3)C(2)Tx nanosheets, a large interface contact area, and favorable Fermi level alignment, which promoted charge transfer and separation efficiency while suppressing electron-hole recombination. Moreover, the Cs2AgBiBr6/ MXenes-based photocatalysts exhibited good repeatability and long-term stability. This work will guide the construction of high-efficiency and stable photocatalytic materials for environmental purification.