Integrating photocatalytic hydrogen evolution with antibiotic degradation over a dual Z-scheme heterojunction

Abstract

The excessive usage of value-added sacrificial agents and poor carrier separation constrain the development of photocatalytic H₂ production. To address these challenges, we propose a waste-to-energy conception by utilizing pollutants as sacrificial agents in heterojunctions with potent carrier separation. Herein, a dual Z-scheme ZnCo₂O₄/C-TiO₂/ZnIn₂S₄ (ZCO/CTO/ZIS) heterojunction was successfully constructed from MOFs with effective carrier separation to integrate H₂ production and organic pollutants degradation in a single photo-redox process. When ciprofloxacin (CIP), a prevalent aquatic contaminant, was substituted for the sacrificial agents to utilize the energy of holes, the dual Z-scheme photocatalyst exhibited excellent hydrogen production performance (∼4.93 ${\text{mmol g}}^{\text{- 1}}{\text{h}}^{\text{- 1}}$). Concurrently, the degradation of CIP was up to 92.21 %, with a 66.71 % mineralization rate. The experimental results combined with theoretical calculations revealed that the interfacial electron field formed at dual Z-scheme ZCO/CTO/ZIS affords fast pathways for charge transfer to achieve the high performance of simultaneous reactions. Additionally, the low toxicity of the degradation intermediates during the bifunctional photocatalysis process implies that this is an environment-friendly route to obtain clean energy. This study provides a feasible strategy for constructing dual Z-scheme photocatalysts from MOFs to alleviate energy crises and environmental pollution.