Cobalt–molybdenum–selenide nanoflowers for bifunctional visible light photocatalysis

The renewability and zero carbon emissions of hydrogen make it a promising clean energy resource to meet future energy demands. Owing to its benefits, photocatalytic water-splitting has been extensively investigated for hydrogen production. However, the low efficiency poses a serious challenge to its implementation. Herein, we attempted to synthesize bimetallic transition metal selenides, namely Co/Mo/Se (CMS) photocatalysts, with varying atomic compositions (CMSa, CMSb, and CMSc) and investigated their photocatalytic water splitting efficiencies. The observed hydrogen evolution rates were as follows: 134.88 μmol g−1 min−1 for CoSe2, 145.11 μmol g−1 min−1 for MoSe2, 167.31 μmol g−1 min−1 for CMSa, 195.11 μmol g−1 min−1 for CMSb, and 203.68 μmol g−1 min−1 for CMSc. Hence, we deemed CMSc to be the most potent photocatalytic alternative among the compounds. CMSc was also tested for its efficiency towards degradation of triclosan (TCN), and results substantiated that CMSc succeeded degrading 98% TCN while CMSa and b were able to degrade 80 and 90% TCN respectively-the attained efficiency being exponentially higher than CoSe2 and MoSe2 taken for comparative analysis in addition to complete degradation of the pollutants leaving no harmful intermediaries during the process. Thus, CMSc shall be identified as a highly potential photocatalyst with respect to both environmental and energy applications. [Display omitted] •Cobalt molybdenum selenide CoMoSe (CMS) nanoflowers were synthesized via a hydrothermal process.•Molybdenum-rich CoMoSe nanoflowers presented the highest photocatalytic H2 evolution rate.•TCN degradation by CoMoSe nanoflowers is beneficial for environmental applications.