Novel Electrocatalysts for Generating Oxygen from Acid Water Electrolysis
Here, for the first time, we focus on layered transition metal dicalchogenides (TMDs) like MoS2 and TaS2 in this search due to their natural abundance and high activity towards hydrogen evolution. We report MoS2 and TaS2, in both their 2H and 1T polymorphs that display excellent catalytic activity for OER in much required acid medium. They are chemically exfoliated to thinner nanosheets from MoS2 precursor and TaS2 nanostructures synthesized by chemical vapour deposition. Structural and electrochemical studies reveal their corresponding semiconducting 2H and metallic 1T polymorph and the impressive electrocatalytic performance respectively. The proliferation of active sites is such a high for those materials that an electrocatalytic current density of 10 mA cm−2 is achievable with overpotential much lower than that of the benchmark IrO2 or RuO2OER catalyst. The Tafel slopes found for the different samples are also in good rivalry of the benchmark catalyst. The performances are also analyzed on the basis of their probable structure relation.
This work presents general strategies to grow nanostructures of layered TMD materials for the enhanced catalytic performance in OER and open up a new avenue in the pursuance of water splitting research towards the growth of hydrogen economy.