Gel-derived NiO–MoS2 for the scalable fabrication of bifunctional screen-printed electrodes for overall water splitting

Abstract

The fabrication of flexible, free-standing electrodes is crucial for advancing renewable energy technologies, particularly in energy conversion and storage. Traditional electrode fabrication methods often involve complex procedures, high material wastage, and limited scalability, whereas screen printing offers a cost-effective, reproducible, and scalable approach for producing high-performance electrodes with uniform coatings. This study introduces a versatile screen-printing strategy for fabricating flexible carbon cloth (CC) electrodes using NiO–MoS₂ ink derived from a solvothermal method. The resulting screen-printed CC electrodes function as efficient bifunctional catalysts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting in alkaline media. The NiO–MoS₂ screen-printed CC electrode exhibits excellent electrocatalytic performance, achieving an OER overpotential (η₁₀) of 382 mV vs RHE with a Tafel slope of 75 mV/dec and HER overpotential (η₁₀) of −159 mV vs RHE and Tafel slope of 116 mV/dec. To further demonstrate its bifunctionality, the NiO–MoS₂ screen-printed CC electrode was assembled into a water-splitting electrolyzer, requiring a cell voltage of 1.79 V to reach a current density of 10 mA/cm² and exhibiting outstanding operational durability. The robustness and structural integrity of the developed electrode is confirmed by the post-stability analysis, highlighting the potential of the methodology reported in this work for the scalable fabrication of high-performance electrodes for water splitting applications.