Recent advancement in BiOI-based nanocomposites for high performance photocatalysts.

BiOI belongs to the family of bismuth oxyhalides (BiOX, X = Cl, Br, I), having a unique layered structure with an internal electrostatic field that promotes the separation and transfer of photo-generated charge carriers. Interestingly, BiOI exhibits higher thermal stability compared to its other BiOX member compounds and absorption spectrum extended to the visible region. BiOI has demonstrated applications in diverse fields such as photocatalytic degradation of various organic pollutants, marine antifouling, etc. Unfortunately, owing to its wide band gap of ∼2.9 eV, its absorption lies mainly in the ultraviolet region, and a tiny portion of absorption lies in the visible region. Due to limited absorption, the photocatalytic performance of pure BiOI is still facing challenges. In order to reduce the band gap and increase the light absorption capability of BiOI, doping and formation of heterostructure strategies have been employed, which showed promising results in the photocatalytic performance. In addition, the plasmonic heterostructures of BiOI were also developed to further boost the efficiency of BiOI as a photocatalyst. Here, in this review article, we present such recent efforts made for the advanced development of BiOI regarding its synthesis, properties and applications. The strategies for photocatalytic performance enhancement have been discussed in detail. Moreover, in the conclusion section, we have presented the current challenges and discussed possible prospective developments in this field.