Oxygen Vacancy-Modified BiOCl Nanoplates via Three Minutes Mannitol-Assisted Grinding Treatment for Excellent Photocatalytic Applications

It remains an exciting challenge to achieve a direct production of oxygen vacancies (OVs) by the one-step grinding of BiOCl visible-light-driven photocatalysts. Herein, BiOCl nanoplates are synthesized via a mannitol-assisted direct grinding method, which exhibits an efficient photocatalytic activity for CO2 reduction and degradation of organic toxins. Different from the previously reported BiOCl synthesized by water/solvatory thermal synthesis, the reaction conditions are mild and the preparation speed is fast. Compared with the BiOCl, the surface area of modified BiOCl-1 nanoplates is enhanced by 13.2 times and has an abundant pore structure. In addition, OVs are introduced in modified nanoplates, which reduce the bandwidth and promote the separation of charge carriers. The CO yield rate of BiOCl-1 reached 27.2 μmol h–1 g–1, which was 8.1 times superior to nonmodified BiOCl (3.4 μmol h–1 g–1). The degradation rate of rhodamine B (20 mg L–1) by BiOCl-0 was only 51.7%, while that of BiOCl-1 reached up to 92.8%. This increases the OVs content and narrows the band gap, which is more conducive to the separation of electron–hole pairs and improves photocatalytic activity. This 3 min grinding with no surfactant-free solid-phase reaction is suitable for large-scale preparation and opens up the possibility for industrial applications.