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

Coupling the electrochemical oxidative upgrading of formaldehyde(FOR) with hydrogen evolution reaction (HER) toward energy-efficientH(2) production and simultaneous chemical production is important,but it still faces huge challenges. Herein, a unique hierarchicalheterojunction is designed by coupling a Ni(OH)(2) nanosheetwith S-modified Ni species on a nickel foam substrate (S-Ni@Ni(OH)(2)/NF) via a two-step strategy. The Ni(OH)(2) nanosheetswith a large surface area contribute to offering sufficient sitesfor the grafting of S-Ni species, constructing a coupled heterostructureto realize greatly improved reaction kinetics for both HER and FORprocesses. As a result, S-Ni@Ni(OH)(2)/NF deliversan overpotential of 50 mV for HER at 10 mA cm(-2) anda 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-inelectrolyzer only needs 1.58 V to realize 50 mA cm(-2) as well as superior stability. This work presents a facile strategyto exploit bifunctional electrodes for hydrogen generation via anenergy-saving way with coupled formaldehyde reforming.