BiOX (X = Cl, Br, I) photocatalytic nanomaterials: Applications for fuels and environmental management.

Energy and environmental issues are the major concerns in our contemporary "risk society". As a green technique, photocatalysis has been identified as a promising solution for above-mentioned problems. In recent decade, BiOX (X = Cl, Br, I) photocatalytic nanomaterials have sparked numerous interest as economical and efficient photocatalysts for energy conversion and environmental management. The distinctive physicochemical properties of BiOX nanomaterials, especially their energy band structures and levels as well as relaxed layered nanostructures, should be responsible for the visible-light-driven photocatalytic performance improvement, which could be utilized in dealing with the global energy and environmental challenges. In this review, recent advances for the enhancement of BiOX photocatalytic activity are detailedly summarized. Furthermore, the applications of BiOX photocatalysts in water splitting and refractory organic pollutants removal are highlighted to offer guidelines for better development in photocatalysis. Particularly, no relative reports in previous studies were documented in CO2 reduction as well as heavy metals and air pollutants removal, thus this review presented as a considerable research value. Challenges in the construction of high-performance BiOX-based photocatalytic systems are also discussed. With the exponential growth of studies on BiOX photocatalytic nanomaterials, this review provides unique and comprehensive perspectives to design BiOX-based photocatalytic systems with superior visible light photocatalytic activity. The knowledge of both the merits and demerits of BiOX photocatalysts are updated and provided as a reference.