Synergistically interface networked organic–inorganic photocatalytic membrane for highly stable Cr(VI) reduction and hydrogen production

Artificial conversion technology based on solar energy is one of most strategic artificial technologies for addressing environmental hazards and energy crisis. However, micro/nano-sized particulate catalysts mostly have the drawbacks of unstable microstructure and difficult recovery, which inevitably limits the practical application of photocatalysis technology. In order to overcome the defects of most inorganic particulate photocatalysts, a novel organic–inorganic photocatalytic membrane based on highly active Bi4Ti3O12/CdS composite and polyvinylidene fluoride (PVDF) was processed for simulated sunlight (SSL)-driven Cr(VI)-to-Cr(III) (CTC) reduction and H2O-to-H2 (HTH) conversion. Due to the maximum light harvesting capacity and synergistically electronic interaction of this synergistically interface networked organic–inorganic membrane, it possesses accelerated dynamics for separating/transferring photoexcitons and restraining photoexciton recombination, thereby outstanding CTC reduction rate (1.25 × 10-2 min−1) and HTH conversion rate (7.45 mmol∙m−2∙h−1) were achieved under SSL-irradiation, and highly stable photoactivity was maintained even being recycled for dozens of times owing to the convenient separation/recovery performance and stable organic–inorganic matrix. Subsequently, a panel reactor for wastewater purification was constructed to achieve 6.5 × 10-3 min−1 of CTC reduction rate under SSL-irradiation. This study provides a prospective insight for application of photocatalysis technology based on the membrane materials.