Facile Substrate-Agnostic Preparation of High-Performance Regenerative Water Splitting (Photo)electrodes

To realize low-cost and sustainable hydrogen production, it is imperative to develop facile approaches to fabricate water splitting (photo)electrodes based on earth-abundant catalysts. In addition, cost benefits can be unlocked if the expended catalysts can be regenerated multiple times on the same substrate. Here, we demonstrate a substrate-agnostic method of depositing NiFe layered double hydroxide (LDH) catalyst via solution corrosion on diverse substrates as water splitting (photo)anodes. Across various substrates, the catalyst deposited electrodes exhibit consistent and sustained water splitting performance as well as possessing regenerative capabilities. Using this method, we also demonstrate a record performance for NiFe LDH/GaAs photoanode, whereby an applied bias photon-to-current efficiency of 11.7% is achieved with excellent photocurrent stability up to 100 h. This study also shows that NiFe LDH deposited by using this technique can sustain high current density operations in alkaline electrolyzer cells for the benefit of industrial water splitting applications. Using the method developed here in preparing low-cost (photo)electrodes on diverse substrate materials, we foresee excellent prospects for delivering high performance and stable water splitting activity for large-scale application.