Controlled growth of highly active NiMoN(100)-decorated porous N-doped carbon nanotubes on carbon cloth as efficient electrodes for alkaline media and seawater electrolysis

The design of a cost-efficient, high-performance electrocatalyst for the hydrogen evolution reaction (HER) is paramount for meeting future energy demands. Herein, we report an effective strategy for growing highly active NiMoxN with preferentially exposed (100) planes decorated with porous N-doped carbon nanotubes (PNCTs) grown on carbon cloth (CC) using 3-amino-1,2,4-triazole (AT) as a nitridation agent. The effects of different nitridation agents (AT and dicyandiamide (DA)) and Mo-to-Ni molar ratios were systematically investigated to optimize the exposed active sites, geometric properties, electronic structures, and chemical composition of NiMoxN. Density functional theory (DFT) calculations revealed that the free energy of H* adsorption (ΔGH*) of the NiMoxN(100) plane was 0.31 eV, which renders it the most active plane among the (101) and (001) planes of NiMoxN. The as-prepared bamboo-like NiMoxN/PNCT@CC exhibited excellent HER performance in the electrolysis of alkaline media and seawater in terms of extremely small η10 values of 52 mV (1 M KOH) and 146 mV (seawater), which are similar to those of Pt/C (η10 = 38 and 129 mV, respectively). The outstanding HER performance originates from the synergistic effects between the highly active NiMoxN(100) plane and PNCTs, which led to a very small ΔGH* of 0.05 eV. This study provides a method for preparing high-performance NiMoxN catalysts.