Less‐Energy Consumed Hydrogen Evolution Coupled with Electrocatalytic Removal of Ethanolamine Pollutant in Saline Water over Ni@Ni₃S₂/CNT Nano‐Heterostructured Electrocatalysts

Abstract

Energy crises, environmental pollution, and freshwater deficiency are critical issues on the planet. Electrolytic hydrogen generation from saline water, particularly from salt‐contained hazardous wastewater, is significant to both environment and energy concerns but still challenging due to the high energy cost, severe corrosion, and the absence of competent electrocatalysts. Herein, a novel strategy is proposed for energy‐efficient hydrogen production coupled with electro‐oxidation removal of ethanolamine pollutant in saline water. To achieve this, an active and durable heterostructured electrocatalyst is developed by in situ growing Ni@Ni3S2 core@shell nanoparticles in cross‐linked 3D carbon nanotubes’ (CNTs) network, achieving high dispersibility and metallic property, low packing density, and enriched exposed active sites to facilitate fast electron/mass diffusion. The unique Ni@Ni3S2/CNTs nano‐heterostructures are competent for long‐term stably electro‐oxidizing environmental‐unfriendly ethanolamine at a high current density of 100 mA cm−2 in saline water, which not only suppresses oxygen and chloride evolution reactions but also decreases the energy consumption to boost hydrogen production. Associated with experimental results, density functional theory studies indicate that the collaborative adsorption of electrolyte ions and ethanolamine molecules can synergistically modulate the adsorption/desorption properties of catalytic active centers on Ni@Ni3S2/CNTs surface, leading to long‐term stabilized electrocatalysis for efficient ethanolamine oxidation removal and less‐energy hydrogen simultaneous production in saline water.

Advanced progress of rhenium (Re)-based electrode materials in electrocatalytic hydrogen evolution: a review

“…Therefore, the optimal catalyst with DG H* z 0 may display superb HER activity in theory. [50][51][52] Nørskov et al presented the volcano curve correlation between the value of exchange current (j 0 , an activity index of catalysts) and DG H* , which was utilized to intuitively judge or predict the HER activity of electrocatalysts. 53,54 Generally, metal Pt was regarded as the benchmark of HER performance owing to the nearest position to the volcano peak of the highest exchange current and the lowest DG H* value close to zero (Fig.…”

Crystallization Engineering of CuNi2S4 Ultra‐Fine Nanocrystals with Optimized Band Structures for Efficient Photocatalytic Pollutant Degradation and Hydrogen Production

“…Furthermore, many single metal sulfides with narrow band gaps and high metallic properties are more useful for electrocatalysis, but they usually cause the high electron-hole recombination rate and weak charge separation efficiency in photocatalytic process. [13][14][15][16] These inherent confinements have adverse effects on their applications in the photocatalytic field. In contrast with single metal sulfides, the bimetal sulfides (ternary compounds of NiCo 2 S 4 , ZnIn 2 S 4 , Cu 2 MoS 4 , etc.)…”

Hybrid-metal hydroxyl fluoride nanosheet arrays as a bifunctional electrocatalyst for efficient overall water splitting

“…Some negatively charged anions, such as S, Se, P, and N, can modulate the electronic properties and improve the charge transfer capability of transition metal hydroxides to accelerate the catalytic performance. [28][29][30][31][32] The F anion is considered because of its robustness, abundance, accessibility, and good stability. 33 Moreover, F anions with strong electronegativity can help to form catalytically active hydroxide/(oxy)hydroxide species on the electrocatalyst surface and thus lead to enhanced catalytic performance.…”