Flux-assisted synthesis of tungsten-doped layered perovskite oxychloride with promoted visible-light-responsive O2 evolution performance

Here, we successfully prepared Ba₂Bi₃Ta₂O₁₁Cl via a simple one-step molten salt method and adjusted its crystal morphology and structure, based on which the O₂-evolving activity was significantly improved. In addition, W doping promotes the charge separation efficiency, lowers the energy barrier for water oxidation reaction, and thus improves the activity. Finally, the optimized W-doped sample after molten salt treatment shows the best O₂ production activity (55 μmol h^-1) without loading any cocatalyst, which is 6 times higher than that of pristine Ba₂Bi₃Ta₂O₁₁Cl and 2 times higher than that of the undoped Ba₂Bi₃Ta₂O₁₁Cl treated with molten salt, respectively.

Controlled preparation of MoS2/PbBiO2I hybrid microspheres with enhanced visible-light photocatalytic behaviour

Novel MoS₂/PbBiO₂I hybrid microspheres were controllably synthesized via the ionic liquid 1-hexyl-3-methylimidazolium iodide ([Hmim]I) assisted solvothermal method. The morphologies, structures, optical and electronic properties of the materials were explored by XRD, XPS, SEM, TEM, DRS, EIS and photocurrent analysis. The photocatalytic activity of MoS₂/PbBiO₂I was evaluated by the degradation of rhodamine B (RhB), antibiotic agent ciprofloxacin (CIP) and bisphenol A (BPA) under visible light irradiation. The photodegradation results showed that the activity of MoS₂/PbBiO₂I was higher than that of pure PbBiO₂I because of suitable band alignment, a larger specific surface area, an enhanced light absorption region, and stronger photocurrent intensity arising from the interface interaction between MoS₂ and PbBiO₂I. The 1.0 wt% MoS₂/PbBiO₂I showed the best photocatalytic performance. Electron spin resonance (ESR) experiments and free radical trapping experiments showed that the superoxide radicals (O₂^-) and holes (h⁺) were determined to be the main active species for the photocatalysis process. A possible mechanism was presented based on the detection and analysis results.