Hierarchically plasmonic Z-scheme photocatalyst of Ag/AgCl nanocrystals decorated mesoporous single-crystalline metastable Bi₂₀TiO ₃₂ nanosheets

The hierarchical photocatalysts of Ag-AgCl@Bi₂₀TiO₃₂ composites have been successfully synthesized by anchoring Ag-AgCl nanocrystals on the surfaces of mesoporous single-crystalline metastable Bi ₂₀TiO₃₂ nanosheets via a two-stage strategy for excellent visible-light-driven photocatalytic activities in the Z-scheme system. First, the single-crystalline metastable Bi₂₀TiO₃₂ nanosheets with tetragonal structures were prepared via a facile hydrothermal process in assistance with the post-heat-treatment route using benzyl alcohol. Especially, the mesoporous Bi₂₀TiO₃₂ nanosheets showed high photocatalytic activity for the degradation of rhodamine B dye under visible-light irradiation. Then, the as-prepared mesoporous Bi ₂₀TiO₃₂ nanosheets were used as a support for loading Ag-AgCl nanocrystals using the deposition-precipitation method and irradiation-reduction process to fabricate the Ag-AgCl@Bi₂₀TiO ₃₂ composites. Inspiringly, the hierarchical Ag-AgCl@Bi ₂₀TiO₃₂ photocatalyst has the higher photocatalytic performance than Ag-AgCl nanocrystals and mesoporous Bi₂₀TiO ₃₂ nanosheets over the degradation of rhodamine B and acid orange 7 dyes, which is attributed to the effective charge transfer from plasmon-excited Ag nanocrystal to Bi₂₀TiO₃₂ for the construction of a Z-scheme visible-light photocatalyst. This work could provide new insights into the fabrication of hierarchically plasmonic photocatalysts with high performance and facilitate their practical application in environmental issues.