Developments in visible-light active TiO2/SnX (X = S and Se) and their environmental photocatalytic applications – A mini-review

The development of novel semiconductor materials and their application as photocatalyst is the emerging area of scientific interest. The surface structures, light absorbance characteristics, charge separation and transfer ability, and stability of photocatalysts are directive aspects towards their efficiency. With these features in mind, a large number of materials have been reported, and amongst them, heterostructure composites of TiO2 with low band gap tin sulphide and selenides (SnX (X = S, Se), have drawn attractive interests to the scientific community. In this review we have emphasized on the alteration in characteristics of TiO2 when it makes composites with tin sulphide and selenides. It is found that narrow bandgap, unique electronic structure, and larger surface-to-volume ratio makes composites of TiO2 with SnX as potential candidates for environment purification. The addition of SnX (X = S, Se) in TiO2 affect the phase formation and morphology of the composites. The light absorption tendency and life span of photoinduced charged carrier was found better after the introduction of SnX in TiO2. All these characteristics directly or indirectly influence the performance of the photocatalysts. This review will enhance the knowledge of the emerging researchers about the influence of SnX (X = S, Se) on the structural, morphological, optical and photocatalytic characteristics of TiO2 that will help them in development of new composites materials possessing the improved photocatalytic activity.