Synergistic enhancement of photocatalytic performance in 2D layered BiOCl through high exposure of intrinsic symmetric electric fields and oxygen vacancies

Environmental pollution control represents a major challenge for modern society, and photocatalytic technology has emerged as a promising approach to address this issue due to its eco-friendly nature and high efficiency. However, the efficiency of photocatalysis is constrained by the rapid recombination and inefficient migration of photogenerated charge carriers. This study proposes an innovative strategy to synergistically enhance photocatalytic performance by maximizing the exposure of intrinsic symmetric electric fields (ISEFs) in two-dimensional layered bismuth oxychloride (BiOCl) and introducing oxygen vacancies (OVs). BiOCl nanosheets with enhanced ISEFs exposure and abundant OVs were successfully synthesized via a hydrothermal method by regulating the ethylene glycol-to-water ratio.The results revealed that exposure of ISEFs significantly reduced the exciton binding energy, thereby facilitating efficient separation and migration of photogenerated electron-hole pairs. Concurrently, the introduction of OVs generated new electronic states near the Fermi level, providing additional pathways for electron transitions, which narrowed the bandgap and enhanced light absorption. Furthermore, OVs shifted the d-band center closer to the Fermi level, significantly enhancing the adsorption capacity for reactant molecules. Experimental results demonstrated that the optimized sample BOC-5 achieved 99 % degradation of rhodamine B (RhB) within 15 min, exhibiting a 55-fold enhancement in performance compared to the sample prepared in pure water.