Hierarchical Ag₃PO₄/TiO₂@C composites derived from Ti₃C₂ MXene for enhanced photocatalytic activity

Herein, a high-performance Ag3PO4/TiO2@C composite photocatalyst was successfully fabricated through the unique structure and interface designs. Firstly, a novel three-dimensional layered carbon-supported titanium dioxides (TiO2@C) nanosheets (NSs) are fabricated by employing the new-type two-dimensional layered transition metal Ti3C2 MXene as carbon skeleton and homologous titanium source via a facile hydrothermal method. Benefiting from the structure characters of Ti3C2 MXene and in-situ growth, the as-prepared TiO2@C NSs own a large surface area and good interface contact. On this basis, taking advantage of the surface electronegativity of Ti3C2 MXene drove TiO2@C, Ag3PO4 nanoparticles are further combined with TiO2@C via an electrostatic self-assembly method to improve the light-harvesting ability. The electrostatic self-assembly process is beneficial to the uniform growth of Ag3PO4 nanoparticles and the formation of a good heterostructure interface between Ag3PO4 and TiO2@C. Therefore, the as-prepared Ag3PO4/TiO2@C composites as photocatalyst exhibit excellent photocatalytic performance, and the optimal photocatalytic degradation rate constant for methylene blue achieves 4.768 x 10(-2) min(-1). The enhanced photocatalytic performance is mainly attributed to the synergistic effect of larger surface area, better light-harvesting ability, and superior charge transfer and separation characters. Additionally, the growth and optimization mechanisms are also deeply studied in the present paper.