LAUSR

Abstract A facile and eco-friendly synthetic method of oxygen reduction reaction (ORR) electrocatalysts is one of crucial steps in the development of large-scale and commercial regenerative energy devices. Herein, a simple and template-free approach is proposed to design CoSx (Co1-xS and Co9S8) nanoparticles encapsulated in N, S-doped carbon substrate (CoSx/NSCS). Interestingly, the carbon substrates are consisted of carbon nanotubes and carbon nanosheets. Moreover, the high-temperature sulfidation step is adopted to form cobalt sulfides and sulfur doping into carbon simultaneously. Benefiting from the N, S doped carbon bedframe and the synergistic effect between cobalt sulfide species and carbon substrate, the optimal CoSx/NSCS-800 (obtained at sulfidation temperature of 800 °C) exhibits robust and excellent ORR electrocatalytic activity in terms of half-wave potential of 0.85 V in alkaline electrolyte. Most importantly, this work, offers great potential to prepare transition metal sulfides nanoparticles integrated with N, S-doped carbon-based electrocatalysts toward ORR.