Construction of hierarchical Mo2C nanoparticles onto hollow N-doped carbon polyhedrons for efficient hydrogen evolution reaction

Highlights: • A new approach of the MOF-assisted self-sacrifice template is successfully obtained and outlined. • Ultra-fine Mo₂C nanoparticles are uniformly embedded into hollow N-doped carbon polyhedrons by a simple thermal treatment. • The as-obtained catalyst (Mo₂C@HNCPs) is of better HER performance and long-term stability in the real application. -- Abstract: In the field of renewable energy, the core of advanced materials lies in the efficiency for the electrocatalytic and photoelectrochemical overall water splitting. However, in hydrogen evolution reaction (HER), there is a lack of electrocatalysts based transition metals of high-performance and natural-abundance, and thus there is a formidable challenge for large-scale application. Therefore, molybdenum carbide (Mo₂C) based catalysts and their composites are regarded as a most promising and replacement noble metal electrocatalyst for the HER in different media about all pH. In this work, the preparation of ultra-fine Mo₂C nanoparticles, which uniformly implant into hollow N-doped carbon polyhedrons (Mo₂C@HNCPs) by adopting MOF-assisted self-sacrifice template approach, is proposed. Mo₂C@HNCPs showcases suitable catalytic activity and feasible stability toward HER in both media such as acidic and alkaline solutions. The as-prepared Mo₂C@HNCPs exhibits effective and fast response from the HER region with nearly 0.0 V onset overpotentials, only requiring 89 mV (0.5 M H₂SO₄ media) and 87 mV (1.0 M KOH media) overpotential to reach 10 mA cm⁻² and cycling stability (<5% performance loss after 10 h). Such distinctive activity of HER is mainly imputed to the poly-dispersion of the ultra-fine Mo₂C nanoparticles and its synergistic contribution of rich nitrogen doping, unique hollow morphology, and abundant active sites at the heterostructures.