CdS based heterojunction for water splitting: A review

Photocatalytic hydrogen (H2) generation from water by using solar energy and photocatalyst is a green and sustainable method to address the energy problems. The development of an extremely efficient photocatalyst is necessary for the commercial and large-scale making of H2. As regards semiconductors based photocatalysts, CdS has mesmerized widespread concentration owing to its moderately narrowing band gap for visible light response and adequately negative potential of the conduction band edge for proton reduction. Previous reports showed that the CdS based heterojunction has tremendous photoactivity for photocatalytic hydrogen production. This comprehensive review highlights the recent reports of design and preparation methods of CdS based heterojunctions. In this perspective, the CdS based heterojunction were categorized as noble metal supported CdS nanocomposites, transition metal supported CdS nanocomposites, GO supported CdS nanocomposites, semiconductors supported CdS nanocomposites, non-metals supported CdS based photocatalyst, metal complexes supported CdS based photocatalysts, carbon nanotubes supported CdS based photocatalysts and metal–organic frameworks supported CdS based photocatalysts. It is expected that this review will stimulate further investigation and open up new possibilities for raising new CdS heterostructure with new and exciting applications. In conclusion, encouraged by the large number of tremendous examples, we have presented some perspectives for the future improvement of CdS based photocatalysts.