Controllable synthesis of P-doped MoS2 nanopetals decorated N-doped hollow carbon spheres towards enhanced hydrogen evolution

Abstract In order to construct the molybdenum disulfide (MoS 2 ) hybrid nanostructure with enhanced conductivity and more active sites towards electrocatalytic hydrogen evolution reaction (HER), hierarchical P-doped MoS 2 nanopetals decorated N-doped hollow carbon spheres (N-C@P-MoS 2 ) core-shell structures were synthesized via calcination and hydrothermal methods. N-C@P-MoS 2 with optimized loadings exhibited favorable HER activities with low onset overpotential (117 mV), small Tafel slopes (68 mV/dec), and fine stability compared with pure MoS 2 nanosheets and all undoped samples. This is largely ascribed to the synergy of MoS 2 and carbon in the rational hierarchical structures, as well as the modified electronic structure with improved conductivity, increased active sites by virtue of N and P doping. Furthermore, P-doped MoS 2 nanosheets were encapsulated in carbon spheres (N-C/P-MoS 2 (inside)) by controlling the dropping rate of adding MoS 2 precursors. As the active sites were hampered, the N-C/P-MoS 2 (inside) revealed poor HER performance compared with the core-shell counterparts. The results demonstrate that the fabrication of hierarchical MoS 2 /carbon composites with the synergy of structural (morphology and content) and electronic (active sites and conductivity) effects induced by various nonmetal doping pave the way for enhanced electrocatalytic HER activities.