The effectiveness of photocatalytic molecular oxygen (O2) activation in pollutant removal relies on the targeted production of reactive oxygen species (ROS). Herein, we demonstrate the dual-pathway activation of O2 on BiOCl through zirconium (Zr) loading. The incorporation of Zr onto the surface of BiOCl not only leads to an increased generation of oxygen vacancies (OV) but also fosters a coupling between the d electrons of Zr and OV, forming dual-active sites known as Zr-oxygen vacancies (Zr-OV). Generally, OV adsorbs O2 and transfers one electron directly to form superoxide radicals (•O2-). Contrary to the conventional single-electron direct activation of O2 to form •O2-, Zr-OV exhibits more flexible coordination and superior electron-donating capabilities. It facilitates O2 conversion to peroxide radicals (O22-) and enables the subsequent generation of •O2- from O22-, significantly promotes the dechlorination and mineralization efficiency of chlorophenol under visible light. This study presents a straightforward strategy to precisely regulate ROS production by expanding pathways, shedding light on the critical role of managing ROS generation for effective pollutant purification.
Keywords: BiOCl; Dechlorination; Dual-pathway; O(2) activation; Photocatalysis.
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