Self-supported bifunctional W-MoS2/FeNi2S4/NF electrodes with superhydrophilicity and superaerophobicity surface for intermittent energy-driven electrocatalytic overall water splitting

Abstract

As energy scarcity and environmental pollution become increasingly problematic, developing non-polluting and sustainable hydrogen production technologies is crucial, with an emphasis on developing high-efficiency and easily available electrolytic hydrocatalysts. Herein, we present a novel, economical self-supporting electrode, W-MoS2/FeNi2S4/NF, fabricated by a simple hydrothermal method. Benefiting from the insitu growth of uniformly dispersed micro- and nanoparticles with an ultrathin nanosheet-like shape on the surface and heterogeneous engineering and heteroatom doping, the catalytic electrodes possess surface superhydrophilic/underwater superaerophobic properties and superb intrinsic catalytic activity. The superhydrophilic/underwater superaerophobic properties of the catalytic electrodes allow for rapid infiltration of the electrolyte solution into the electrode and accelerate mass transfer while also allowing for the desorption of bubbles from the electrode surface and avoiding the bubble shielding effect, resulting in a significantly increased electrocatalytic rate. With current densities as high as 10 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, W-MoS2/FeNi2S4/NF displayed lower overpotentials of 92 and 177 mV. More impressively, only a low cell voltage of merely 1.5 V is sufficient to achieve a current density of 10 mA cm−2, achieve overall water splitting in an alkaline electrolyte, and exhibit up to 20 h electrochemical durability. Above all, it has been demonstrated that surplus electricity from intermittent energy sources may be used to create eco-friendly hydrogen energy by electrolyzing water, preventing resource waste. This work provides novel insights into the preparation of inexpensive, high-efficiency bifunctional electrocatalysts and new directions for intermittent energy generation for hydrogen production.