A Molten‐Salt Method to Synthesize Co₉S₈ Embedded, N, S Co‐Doped Mesoporous Carbons from Melamine Formaldehyde Resins for Electrocatalytic Hydrogen Evolution Reactions

Abstract

We developed a molten salts process to prepare Co9S8 nanoparticles (NPs) entrapped, S, N co‐doped carbons. Cobalt chloride was used as the cobalt source. The melamine‐formaldehyde (MF) resin provided the carbon source and nitrogen source, and thiourea provided sulfur source. In addition, common inorganic salts were added as templates to generate pores. The characterization results showed that the prepared materials contained high contents of N, S and Co, and were mesoporous composites. At the same time, the porosity of electrocatalyst depended on the type of salt and the mass ratio of precursor to salt, which further affected the electrocatalytic activity of hydrogen evolution reaction (HER). The best prepared catalyst showed excellent HER performance. The onset overpotential of the catalyst was low (33 mV) and had a small Tafel slope (61.1 mV dec−1), in addition to good stability in alkaline media.

Novel WS2/Co9S8 nanoparticles supported on N, S co‐doped mesoporous carbon as efficient electrocatalyst for hydrogen evolution reaction

“…The introduction of these inorganic salts can reduce the synthesis cost, which can also be recycled [24,25] . In our prior reports, various cobalt sulfide‐based electrocatalysts for HER were synthesized via the molten salts process, which possessed outstanding HER performance due to high surface area and pore volume (Table S1) [26–29] . However, with the rapid development of lithium‐ion battery industry, the price of cobalt‐containing minerals and raw materials remains high.…”

“…[24,25] In our prior reports, various cobalt sulfide-based electrocatalysts for HER were synthesized via the molten salts process, which possessed outstanding HER performance due to high surface area and pore volume (Table S1). [26][27][28][29] However, with the rapid development of lithium-ion battery industry, the price of cobalt-containing minerals and raw materials remains high. Doping some transition metals with lower price in cobalt sulfide material can greatly reduce the synthesis cost of catalyst.…”