Recent Developments and Perspectives of Cobalt Sulfide-Based Composite Materials in Photocatalysis

Abstract

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.

Photocatalytic Conversion of Diluted CO2 into Tunable Syngas via Modulating Transition Metal Hydroxides

“…In the absence of cocatalysts, the production rates of CO (172 μmol g −1 h −1 ) and H 2 (90 μmol g −1 h −1 ) by Ru are relatively low because the recombination of photogenerated electron−hole pairs is high and the surface active sites are less. 31 Notably, the addition of GR, Ni(OH) 2 cocatalysts, and Co(OH) 2 cocatalysts into the Ru solution can obviously improve the photocatalytic conversion of diluted CO 2 upon light irradiation. As shown in Figure S7, the Ni(OH) 2 sample produces 3659 μmol g −1 h −1 of CO and 1083 μmol g −1 h −1 of H 2 , and the formation rates of CO and H 2 are 993 and 8605 μmol g −1 h −1 , respectively, for the Co(OH) 2 catalyst.…”

“…In the absence of cocatalysts, the production rates of CO (172 μmol g –1 h –1 ) and H 2 (90 μmol g –1 h –1 ) by Ru are relatively low because the recombination of photogenerated electron–hole pairs is high and the surface active sites are less . Notably, the addition of GR, Ni­(OH) 2 cocatalysts, and Co­(OH) 2 cocatalysts into the Ru solution can obviously improve the photocatalytic conversion of diluted CO 2 upon light irradiation.…”

Metal Oxide Nanoparticles’ Green Synthesis by Plants: Prospects in Phyto- and Bioremediation and Photocatalytic Degradation of Organic Pollutants

“…When exposed to visible sunlight, photocatalysts can degrade organic molecules similarly to semiconductors. A hole is created in the valence band because of excitably moving an electron from the valence band to the conduction band [120][121][122].…”

Low-Temperature Solvothermal Growth of CoxSy Nanospheres on Conducting Substrates as Efficient Electrodes for Hydrogen Evolution Reaction

“…Most of the earlier studies in this area were focused on molybdenum (Mo) and tungsten (W)-based chalcogenides. In previous years, cobalt sulfide materials like CoS 2 , Co 3 S 4 , and Co 9 S 8 garnered great attention for electrocatalytic applications owing to their excellent metallic conductivity, good intrinsic activity, and earth abundance. – Recently, Co 3 S 4 and Co 9 S 8 have attracted particular interest for the catalytic application of HER due to the presence of sulfur vacancies and their Co-rich nature, which can act as active sites for the HER and oxygen evolution reaction. – Various methods, such as heterointerface engineering, defect introduction, and doping, are employed to further improve the catalytic activity of cobalt sulfides to achieve a performance comparable to that of Pt. – …”