Dual Modification Strategy of Nickel Sulfide as pH-Universal Catalysts for Hydrogen Production at Large Current Density

Abstract

Developing highly efficient electrocatalysts for large-scale implementation of the hydrogen evolution reaction (HER) at a large current density is critical for renewable H2 fuel. The designed electrocatalysts by non-noble metals are expected to operate well at wide pH conditions, but it remains a major challenge. In this work, a novel dual modification strategy is applied to develop a series of P/Mo modified Ni3S2 on nickel foam (denoted as P-MNS/NF) as pH-universal electrocatalysts for HER. Benefiting from the plentiful catalytic active sites, optimized electronic structure, and improved reaction kinetics, the P-MNS/NF electrode realizes remarkable catalytic activity and stability at a large current density. The optimal P3-MNS3/NF catalyst exhibits the low overpotential of 245 and 243 mV at a high current density of 1 A cm–2 for both alkaline/acidic media. Those are promising performance results compared to those of the other nickel sulfide-based materials. Importantly, this P3-MNS3/NF can also achieve good performance in a neutral electrolyte. This needs a small overpotential of 360 mV to reach the current density of 0.5 A cm–2. Our strategy provides a new method to guide rational design of highly active HER electrocatalysts over a wide pH window.

Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments

“…A common feature of the papers published on this topic over the past two years is the significant increase in HER activity. [1175][1176][1177][1178][1179][1180] Metallic vanadium sulphide (VS n ) embedded in a MoS 2 film (to result in a V-MoS 2 film) are highly active HER catalysts, as shown by Kim's group: 1178 VS n units are formed in the basal plane of MoS 2 (Fig. 79), leading to an impressive HER current density of 1000 mA cm À2 at 600 mV overpotential during water electrolysis experiments.…”

“…HER efficiency experienced a real boost from work that was published very recently. 1179,[1184][1185][1186][1187][1188][1189] Phosphorisation of NiSe 2 nanoplate arrays delivered a selfsupported electrocatalyst comprising a nickel chalcogenide (NiSe 2 ) and a nickel pnictide (Ni 2 P) phase 1188 (Fig. 81) and turned out to highly efficiently and stably support HER electrocatalysis in 1 M KOH (Z = 66 mV; j = 10 mA cm À2 ).…”

Engineering Sulfur Vacancies in Spinel-Phase Co3S4 for Effective Electrocatalysis of the Oxygen Evolution Reaction

“… 2 − 5 Therefore, the oxygen evolution reaction (OER) plays an essential role in solar and electricity-driven water splitting devices, regenerative fuel cells, and rechargeable metal–air batteries. 4 , 6 − 9 However, owing to kinetic energy barriers, the potential required for driving the reaction is much larger than the thermodynamic equilibrium potential (1.23 V vs reversible hydrogen electrode, RHE). Moreover, the large-scale application of noble metal oxides (IrO 2 or RuO 2 ) with high activity toward the OER is limited by the scarcity of their reserves and easy corrosion during the reaction.…”

The hybrid engineering of crystalline NiSex nanorod arrays with amorphous Ni–P film towards promoted overall water electrocatalysis

“…In addition, synthesizing electrocatalysts on conductive substrates (e.g., metal foam and carbon materials) via in situ growth methods is another strategy. [26][27][28] Impressively, recent research has manifested that interfacial engineering between hybrid electrocatalysts and heterostructures can significantly change the intrinsic catalytic properties of the individual components, producing heterostructures with larger surface areas, creating more channels for mass/charge transfer, and leading to better contact between the catalyst and electrolyte, ultimately affecting the catalytic performance. [29][30][31][32][33][34] As a representative work, Pan et al constructed a Ni 2 P/Ni 3 S 2 heterostructure with three-dimensional (3D) networks, which exhibited good electrocatalytic activity and excellent stability toward both the HER and OER.…”