Controlled synthesis of thin BiOCl nanosheets with exposed {001} facets and enhanced photocatalytic activities

Abstract

Thin BiOCl nanosheets with exposed {001} facets were synthesized by controlling the concentration of hydrochloric acid (HCl). The thickness of the BiOCl nanosheets with exposed {001} facets changed from 7–200 nm with an increase in HCl concentration. The thinnest BiOCl nanosheet with a thickness of 7–15 nm was obtained when the concentration of HCl was 8 mmol L⁻¹. The photocatalytic activity of these thin nanosheets with exposed {001} facets is enhanced gradually with a decrease in the thickness of the nanosheets, which is ascribed to the shorter and shorter distance provided for photogenerated electron–hole pairs to be rapidly separated along the [001] orientation driven by the self-induced internal static electric fields. Moreover, thin BiOCl nanosheets with a large surface area provide more active sites for dye adsorption, and thus enhance the dye photosensitization degradation of pollutants. This work provides a promising method for preparing other metal oxyhalide materials with controllable nanosheet thickness.