Cobalt Oxide nanomaterial on MoS2 quantum dots as a heterojunction photocatalyst for water splitting.

Abstract

The primary objective of this MPhil research is to investigate the hydrogen evolution reaction (HER) via water splitting using new Molybdenum disulfide (MoS2) incorporated cobalt oxide photocatalysts. Cobalt oxide has been extensively investigated and proven to be an efficient, and well-established photocatalyst for catalytic applications including organic degradation, CO2 reduction, and water splitting. This research has explored a rapid and reliable synthesis technique using microwave (MW) irradiation for fabricating cobalt oxide photocatalysts by varying the polyvinyl alcohol as a reaction template precursor. Leveraging the well-known microwave technology for its high kinetic and energy efficiency over conventional hydrothermal and solvothermal technology to synthesize nanomaterials, the advantage of this microwave technique to synthesize cobalt oxide and co-catalyst was explored and established for the first time. The novelty of this research can be summarized as following. Firstly, the reduction in cobalt oxide synthesis time to 99.6% compared to the average required for hydrothermal process from a 21 hours range to 2 minutes. Secondly, exploring MoS2 QD synthesis using microwave irradiation is unprecedented to my knowledge. Lastly, the synthesis of Z-scheme heterojunction of the two semiconductor materials (MoS2 QD and cobalt oxide) for hydrogen evolution reaction is reported for the first time.