Surface-Plasma-Induced One-Pot Synthesis of N,S-Carbon Dot Intercalated MoS2/Graphene Nanosheets for Highly Efficient Hydrogen Evolution Reaction

Abstract

Herein, a facile and rapid surface-plasma-induced method was adopted for the one-pot synthesis of a 2D/0D/2D hybrid nanostructure consisting of N,S co-doped carbon dots (NSCD) intercalated few-layer MoS2/graphene nanosheets (MoS2/G) as an excellent catalyst for the hydrogen evolution reaction (HER). In this process, bulk MoS2 and graphite foil served as the sources of MoS2 and graphene nanosheets, respectively, while glucose and thiourea served as the source of NSCD. The sturdy integration of 0D NSCD and 2D MoS2/G in a well-constructed ternary composite provided a huge number of edge active sites with tunable and extraordinary physicochemical properties for electron transport, facilitating HER performance. The optimal NSCD@MoS2/G exhibited a superior catalytic activity toward HER with a low onset potential (37 mV), an overpotential of 98 mV at 10 mA cm–2, and a Tafel slope as small as 53 mV dec–1, which were better than other 2D electrocatalysts. The increase in double-layer capacitance for NSCD@MoS2/G (12.2 mF cm–2), which was 2-fold of the MoS2/G sample, is strong evidence of the large catalytic edge sites and electrical coupling in the NSCD@MoS2/G ternary system. Moreover, the strong bonding and interaction between NSCD and MoS2/G nanosheets enabled outstanding long-term stability and structural integrity, displaying 95 and 90% activity retention at 10 and 50 mA cm–2 after 48 h i–t test, respectively. This approach paves the way to efficient syntheses of 2D/0D/2D heterostructures with great potential for various energy-related applications.