Sulfur-Modified Nickel-Based Hybrid Nanosheet as a Robust Bifunctional Electrode for Hydrogen Generation via Formaldehyde Reforming

Abstract

Coupling the electrochemical oxidative upgrading of formaldehyde (FOR) with hydrogen evolution reaction (HER) toward energy-efficient H2 production and simultaneous chemical production is important, but it still faces huge challenges. Herein, a unique hierarchical heterojunction is designed by coupling a Ni­(OH)2 nanosheet with S-modified Ni species on a nickel foam substrate (S–Ni@Ni­(OH)2/NF) via a two-step strategy. The Ni­(OH)2 nanosheets with a large surface area contribute to offering sufficient sites for the grafting of S–Ni species, constructing a coupled heterostructure to realize greatly improved reaction kinetics for both HER and FOR processes. As a result, S–Ni@Ni­(OH)2/NF delivers an overpotential of 50 mV for HER at 10 mA cm–2 and a low potential of 1.36 V to acquire a current density of 50 mA cm–2 for FOR. For the HER||FOR-coupled system, the built-in electrolyzer only needs 1.58 V to realize 50 mA cm–2 as well as superior stability. This work presents a facile strategy to exploit bifunctional electrodes for hydrogen generation via an energy-saving way with coupled formaldehyde reforming.

Interface Engineering of a Hierarchical P-Modified Co/Ni3P Heterostructure for Highly Efficient Water Electrolysis Coupled with Hydrazine Degradation

“…The composition after the catalysis remains unchanged. The difference is that the low-valence state of Ni 0 species appear after HER catalysis, while the high-valence Co 3+ and Ni 3+ species appear after HzOR, indicating that the (Co/Ni 3 P) A3 catalyst surface undergoes the reconstruction process of catalytic species under electrochemical oxidation and reduction conditions. – Therefore, the (P–Co/Ni 3 P) A3 /NF electrode has superior catalytic activity and stability for both HER and HzOR, and the morphology and composition undergo little changes after a long-term stability test.…”

Water electrolysis for hydrogen production: from hybrid systems to self-powered/catalyzed devices

“…To date, the reported FOR catalysts have been concentrated on Cu-based materials, such as Cu 2 O catalyst, 420 ZrO 2 –CuO/Au, 421 Ni doped Cu, 422 Cu 2 O, 423 hollow PdCu alloy, 424 and Cu nanosheet arrays. 425 Some other transition metal-based catalysts, such as Ni nanowires, 426 S-Ni@Ni(OH )2 /NF, 427 NiCo–NiCoP@PCT, 428 NiMn phosphates, 429 S-doped MnO 2 , 430 and Co–N x –C@Co, 431 have also been used for the FOR.…”

Anion-modulated CoP electrode as bifunctional electrocatalyst for anion-exchange membrane hydrazine-assisted water electrolyser

“…14–16 It has the advantage of significantly reducing the voltage of hydrogen production without posing additional safety risks. 17–19 Therefore, the development of non-precious metal electrocatalysts with high catalytic activity and good stability is critical for the hydrazine-assisted AEMWE system.…”