Synergistic effect of photocatalytic U(VI) reduction and chlorpyrifos degradation by bifunctional type-II heterojunction MOF525@BDMTp with high carrier migration performance

Abstract

The radioactive ion U(VI) and organophosphorus pollutants in sewage do great harm to the ecological environment and human health. Bifunctional photocatalyst MOF525@BDMTp was prepared by in-situ covalent bridging method, and U(VI) and chlorpyrifos (CP) were removed by one-to-two strategy. MOF525@BDMTp had high carrier migration performance and conformed to the type-II heterojunction. Under light conditions, electrons were transferred from MOF525 to BDMTp due to the action of the built-in electric field, increasing the electron density of BDMTp and thus activating the U(VI) binding sites. BDMTp interacted with S and N atoms in CP to promote its hydrolysis and oxidation by h+ and ·O2-. Thus, MOF525@BDMTp guaranteed the simultaneous reduction of U(VI) on BDMTp and the oxidation of CP on MOF525. Therefore, designing functional integrated composites is an effective means to improve the photocatalytic performance of composite materials in complex environments.