A comprehensive review of synthetic methodologies, photo/photoelectro-catalytic hydrogen evolution performance and pollutant degradation capabilities of CuGaS2 based materials

Copper gallium sulfide (CuGaS 2 ) is an important candidate of the group I-III-VI 2 semiconductor family. CuGaS 2 has a direct band gap of ∼2.49 eV, which falls in the visible range. The advantages of CuGaS 2 also include environmentally friendly elemental components, tunable band gap alignment and excellent light harvesting property. These properties make CuGaS 2 an emerging candidate for visible light induced photocatalysis, photoelectrocatalysis and photovoltaic applications. In addition, the properties of CuGaS 2 can vary depending on the polymorphic phase, which includes chalcopyrite, wurtzite and zinc blende. The synthesis methods play a crucial role in the phase stabilization and properties of CuGaS 2 . This review summarizes the different synthesis methods adopted for the preparation of CuGaS 2 and their unique experimental factors that play an important role in the desired phase, morphology and application. The prescriptive role of solvent, temperature, surfactant, etc., is discussed. Despite the diverse applications of CuGaS 2 , this review mainly focuses its effectiveness in terms of photocatalytic and photoelectrocatalytic potency in H 2 generation and pollutant degradation. A detailed discussion on the mechanistic pathways for the photocatalytic and photoelectrocatalytic properties and the enhancement of the properties by doping and heterostructure assembly is emphasized. Some other applications of CuGaS 2 are also concisely discussed. In addition, the challenges and future prospects for improving the properties of CuGaS 2 in photo/photoelectro-catalytic applications are emphasized in this review. Graphical abstract • Comprehensive discussion on the various synthesis methods of CuGaS 2 . • An overview of phase stabilization and tuning the morphology of CuGaS 2 . • Photo/photoelectro-catalytic H 2 production and pollutant degradation applications are discussed. • Challenges and future perspective of CuGaS 2 based materials was highlighted.