BiOCl

BiOCl, or bismuth oxychloride, is a chemical compound with the formula BiOCl. It is a layered bismuth oxyhalide, part of the BiOX (X = Cl, Br, I) family. The structure comprises sheets of BiO units connected to oxide and chloride layers, forming a tetragonal matlockite-type lattice. The layers create a two-dimensional framework that leads to anisotropic properties.

BiOCl is a wide-band-gap semiconductor with an optical band gap of about 3.2–3.4 eV, absorbing primarily in the ultraviolet region. This makes it relatively transparent to visible light and of interest for UV-protection applications, although its photocatalytic activity is enhanced by nanoscale morphology or dopants.

Preparation of BiOCl can be achieved by simple precipitation from Bi3+ sources with chloride under alkaline conditions, or by hydrothermal/solvothermal routes to obtain nanoscale sheets. Morphology often includes nanosheets with high aspect ratio, and doping with metal or nonmetal elements can modify the band gap and charge separation properties.

Applications include use as a pearlescent pigment in cosmetics and coatings due to its refractive and shimmering properties. In research and environmental contexts, BiOCl and its nanostructures are studied as photocatalysts for degradation of dyes and organic pollutants under UV light, with enhancements reported from doping or coupling with other semiconductors.

Safety notes: as an inorganic bismuth compound, BiOCl is relatively low in toxicity compared with many heavy metals, but standard handling precautions apply.

BiOCl is part of the broader BiOX family and is often compared with BiOBr and BiOI in studies of structure, properties, and applications.