Nanointerface engineering Z-scheme CuBiOS@CuBi2O4 heterojunction with O S interpenetration for enhancing photocatalytic hydrogen peroxide generation and accelerating chromium(VI) reduction

Designing a core-shell nanointerface is beneficial for enhancing the photocatalytic performance of hydrogen peroxide (H2O2) production. Hence, a direct Z-scheme one-dimensional (1 D) CuBiOS@CuBi2O4 nanorods with a core (oxide)-shell (sulfide) nanostructure and OS interpenetrated nanointerface was controllably synthesized through in-situ anion exchange. The formation of OS interpenetration at the heterogeneous interface with surface oxygen vacancies could effectively boost light absorption, reduce the interface contact resistance, facilitate band bending, and thus enhance charge separation and transfer as a "bridge". The as-prepared catalyst with tunable OS nanointerface greatly improved the photocatalytic performances in the H2O2 production with a yield of 201.9 μmol·L-1 and the in-situ generated H2O2 effectively accelerated the reduction of chromium(VI) (Cr(VI), 95.4% within 15 min). The excellent performances were due to the OS interpenetration with rich oxygen vacancies and unique shell-core structure with intimate contact inter-doping nanointerface. Moreover, the photocatalytic mechanism was discussed in detail. This work might provide a guideline in the design and construction of high-performance catalysts with well-defined nanointerface for various applications.