GR and Ni₂P dual cocatalysts modified ZnIn₂S₄ nanoflower has been prepared and they can simultaneously utilize photogenerated electrons and holes to actuate the oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) integrated with H₂ evolution.

Photocatalysis, as an inexpensive and safe technology to convert solar energy, is essential for the efficient utilization of sustainable renewable energy sources. Earth-abundant cobalt sulfide-based composites have generated great interest in the field of solar fuel conversion because of their cheap, diverse structures and facile preparation. Over the past 10 years, the number of reports on cobalt sulfide-based photocatalysts has increased year by year, and more than 500 publications on the application of cobalt sulfide groups in photocatalysis can be found in the last three years. In this review, we initially summarize the four common strategies for preparing cobalt sulfide-based composite materials. Then, the multiple roles of cobalt sulfide-based cocatalysts in photocatalysis have been discussed. After that, we present the latest progress of cobalt sulfide in four fields of photocatalysis application, including photocatalytic hydrogen production, carbon dioxide reduction, nitrogen fixation, and photocatalytic degradation of pollutants. Finally, the development prospects and challenges of cobalt sulfide-based photocatalysts are discussed. This review is expected to provide useful reference for the construction of high-performance cobalt sulfide-based composite photocatalytic materials for sustainable solar-chemical energy conversion.

A hierarchical hybrid cocatalyst is constructed by in situ anchoring Co(OH)₂ nanosheet arrays on graphene. Using Eosin Y as a photosensitizer, the Co(OH)₂-GR hybrid showed superior performance in photocatalytic H₂ evolution.