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The establishment of an efficient and economic means of producing hydrogen via electrocatalytic water-splitting will facilitate the extensive commercialization of fuel cells, and the round-the-clock model of electrocatalytic hydrogen production will alleviate the intermittency issue associated with sustainable energy sources. To enable this feature of renewable hydrogen energy, the key point is to develop cheap, large-scale and high-performance hydrogen evolution electrocatalysts as an alternative to noble metals. Here, a simple and robust physically sputtering strategy is reported to massively prepare a porous and defect-enriched W2C@WC1−x film electrocatalyst on carbon cloth (CC) in a W, C and Ar ion plasma atmosphere. The preferential re-sputtering mechanism promotes the loss of activated W and C ions in plasma and extracts more C from plasma, resulting in the ultimate formation of a defective W2C@WC1−x film. The ratio of W2C to WC1−x increased and the particle size decreased when additional nano-scale thickness Mo sublayers were further incorporated. A monolithic and porous W2C@WC1−x/Mo multilayer film as a binder-free electrocatalyst on flexible CC is created. It exhibits excellent HER performance with a low overpotential of 58 mV vs. RHE to drive a current density of −10 mA cm−2, a low Tafel slope of 41 mV dec−1 and over 6 days of long-term running stability in 0.5 M H2SO4 solution. It outperforms most of the recently reported outstanding non-noble metal electrocatalysts. This work sheds light on a new route to regulate the tungsten-carbide catalyst morphology and composition with an aim to boost its HER activity.

The availability and catalytic activity of the cost-efficient electrocatalysts are the dominant factors for the hydrogen evolution reaction (HER) performance in the renewable hydrogen economy. Extensive efforts have been devoted to maximize the amount of various active sites in non-noble-metal electrocatalysts for HER. This work reported a physically sputtering strategy to construct porous and ordered 2H-MoS2 films with mono-/di-/tri-types of active sites via controlling the film thickness (from ∼15 to 3050 nm) in the energetic plasma. As the pure (2H-) MoS2 for HER electrocatalyst, the as-fabricated 3050 nm additive-free columnar film electrode shows a stable electrochemical activity for HER (an overpotential of 204 mV at a current density of −10 mA/cm2). Interestingly, the MoS2 film with controllable thickness can serve as an innovative platform to study the electrocatalytic activity of the customized different active sites (the exposed active edge of sheets (eE), stepped-termination surfaces (sS), and terrace on the basal planes (tB)) and the dependence of electrocatalytic efficiency of the vertically aligned MoS2 eE active sites on their distance to the current collector. The results first revealed that the tB active sites possessed almost the same electrocatalytic activity as that of the eE active sites but higher than the sS active sites. The electrocatalytic efficiency of the eE active sites decreased as their distances to the current collector were gradually increasing, due to the limited conductivity of the semiconductive 2H-MoS2 sheets. This work proposes and evaluates a facile strategy for replying to the question of how to investigate the electrocatalytic activities of various active sites in the electrocatalysts.