Ultrathin MoSe 2 Nanosheets Coated on Hollow Carbon Spheres as Efficient Hybrid Catalyst for Hydrogen Evolution Reaction

Abstract

Two-dimensional transition metal chalcogenide is a promising non-precious metal electrocatalyst for hydrogen evolution reaction (HER); however, the improvement of an inefficient catalytic activity is still a major challenge at present due to their limited active sites and low conductivity.In this work, we present ultrathin MoSe nanosheets were coated on hollow carbon spheres (HCS) surface through strong 2 interaction with surface hydrophilic functional groups OH to fabricate a core-shell HCS@MoSe hybrid catalyst.The MoSe structure with 2 2nanosheets could effectively expose more active edges and the HCS core further provides a beneficial conductivity.Finally, the obtained -1 composite shows the remarkable HER activity with a small Tafel slope of 74 mV dec , a small overpotential of 200 mV at a current density of -2 10 mA cm , and an excellent long-term durability.Therefore, this Pt-free and highly efficient electrocatalyst shows its great potential for renewable hydrogen production. Experimental ChemicalsAbsolute ethanol, NaOH (99 %), formaldehyde (37 wt%), ammonia solution (25 wt%), Na MoO (99.0 %), selenium (99.9 %), hydrazine 2 4 hydrate (N H H O, 80 wt%) solution, resorcinol (99.5 %), 2 4 2 ethylorthosilicat (98 %) were used without further purification.All chemicals were purchased from Sinopharm Chemical Reagent Co., Ltd. Preparation of Hollow Carbon SpheresAmmonia aqueous solution (3 mL, 25 wt%) was added to a mixture of 10 mL deionized water and 70 mL ethanol.After the solution was stirred for 30 minutes, 3.46 ml ethylorthosilicate (TEOS), 0.4 g resorcinol and 0.56 ml formaldehyde solution (37 wt%) were added to ES Mater.