Self‐Templating Construction of Hollow Amorphous CoMoS₄ Nanotube Array towards Efficient Hydrogen Evolution Electrocatalysis at Neutral pH

Environmentally friendly electrochemical hydrogen production needs the development of earth-abundant catalyst materials for the hydrogen evolution reaction with high activity and durability at neutral pH. In this work, the self-templating construction of a hollow amorphous CoMoS₄ nanotube array on carbon cloth (CoMoS₄ NTA/CC) is reported, using hydrothermal treatment of a Co(OH)F nanowire array on CC in (NH₄ )₂ MoS₄ solution. When used as a 3D electrode for hydrogen evolution electrocatalysis, the resulting CoMoS₄ NTA/CC demonstrates superior catalytic activity and strong long-term electrochemical durability in 1.0 M phosphate buffer solution (pH=7). It shows small onset overpotential of 21 mV and requires low overpotentials of 104 and 179 mV to drive geometrical current densities of 10 and 50 mA cm^-2 , respectively. Density functional theory calculations suggest that CoMoS₄ has a more favorable hydrogen adsorption free energy than Co(OH)F.