Bioi

BiOI is bismuth oxyiodide, a member of the BiOX family (X = Cl, Br, I) of layered oxyhalides. Its chemical formula is BiOI, and it is studied as a p-type semiconductor with activity in the visible spectrum.

BiOI crystallizes in a layered structure in which positively charged [Bi2O2]2+ sheets alternate with iodide layers. This lamellar arrangement supports charge separation within the material and contributes to its optoelectronic properties. The band gap is typically reported around 1.8 eV, placing BiOI in the visible region and enabling light-driven processes.

Synthesis of BiOI can be achieved by several methods, including hydrothermal or solvothermal routes, precipitation, and electrodeposition. Precursors such as bismuth salts and iodide sources are commonly used, often with conditions that promote the formation of the characteristic layered morphology.

Applications of BiOI center on its visible-light photocatalytic activity. It has been investigated for degradation of organic pollutants, dyes, and pharmaceuticals under visible light. In composite form, BiOI is frequently paired with other semiconductors or dopants to enhance charge separation and broaden light absorption, improving photocatalytic efficiency and, in some cases, facilitating hydrogen production.

Enhancements for BiOI performance commonly involve forming heterojunctions with materials like TiO2 or g-C3N4, adding noble metal co-catalysts, or doping and defect engineering. Such strategies aim to suppress electron–hole recombination and improve carrier mobility.

BiOI is part of the broader BiOX family, with related compounds BiOCl and BiOBr offering different band gaps and properties. It is important to handle BiOI according to standard chemical safety practices for iodide-containing materials.