Facile In Situ Synthesis of an Ultrafine and Defect-Rich Co-doped MoS2 Nanocluster Catalyst for Efficient Hydrogen Evolution Reaction in Alkaline Medium

It is significantly important but still challengeable to explore high efficient non-noble metal electrocatalysts for hydrogen evolution reaction (HER) in alkaline medium. In this work, porous, tiny, and defect-rich CoMoS/Ketjen black (KB) nanomaterials were in situ prepared by employing the uniform and small-size nanoscaled reduced polyoxometalates as the template and anchor site for metal salts, which are beneficial for the exposure of abundant edge active sites in this microstructure and also decrease the mass transfer resistance. Moreover, with the Co doping into the lattice of MoS2, it facilitated the electron transport from Co to Mo and thus accelerated the Volmer reaction kinetic of the HER catalytic process. This CoMoS/KB composite exhibits a low overpotential (81 mV vs RHE) of 10 mA cm–2 and excellent stability in 1 M KOH.