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

Abstract

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.

Cobalt modification of nickel–iron hydroxide electrocatalysts: a pathway to enhanced oxygen evolution reaction

“…In the first step, a piece of pristine Ni foam (NF) substrate is immersed in a combined solution of Ni( ii ) and Fe( iii ) chloride to form bimetallic NiFe LDH, which is akin to our previously reported work. 26 Following this, the deposited sample is subsequently immersed in a Co( ii ) chloride solution, leading to the formation and integration of Co hydroxide with the pre-existing NiFe LDH layer to form a NiFeCo hydroxide structure on the substrate (NiFeCo/NF). Both solution corrosion processes are conducted at room temperature.…”

“…In recent times, there has been growing attention towards utilizing a solution-corrosion approach to synthesize multimetallic metal hydroxides. [26][27][28] This technique uses reactive anions in the metal precursor solutions to corrode the surface of the metal substrate, which then facilitates a redox reaction on the corroded sites to deposit metal hydroxide layers on top of the surface. Besides being scalable, this technique is also proven to be adaptable for use in a variety of metallized substrates.…”

“…Besides being scalable, this technique is also proven to be adaptable for use in a variety of metallized substrates. 26 In this study, we explore the effects of modifying NiFe LDH with Co using a simple, room temperature solution corrosion process. We present that adding Co improves the intrinsic OER activity of NiFe LDH by reducing the charge transfer resistance and turnover frequency.…”

“…Besides being scalable, this technique is also proven to be adaptable for use in a variety of metallized substrates. 26…”

Plasma‐Driven Synthesis of Self‐Supported Nickel‐Iron Nanostructures for Water Electrolysis

“…Hence, recent efforts have been devoted for developing lowcost, earth-abundant electrocatalysts. [2][3][4][5][6][7][8] Amongst the alternatives, nickel (Ni) is a well-known material and has been extensively studied for water electrolysis in alkaline media. [9][10][11][12] Particularly, nickel-iron compounds are considered as promising materials due to the synergistic effects between nickel and iron.…”