The depletion of fossil fuels and growing concerns about energy and environmental issues have prompted extensive research efforts to develop alternative energy sources. Electrochemical electrolysis of water is considered a promising strategy for hydrogen fuel production. However, efficient water cracking requires efficient and long-lasting electrocatalysts that can accelerate the kinetics of oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). Noble metal-containing catalysts, such as Pt and its alloys, RuO2 and IrO2, are currently the most effective catalysts for OER and HER. However, the high cost and scarcity of precious metals have hindered their large-scale application and the development of renewable energy technologies. To overcome these limitations, a great deal of effort has been put into designing and synthesizing non-precious metal electrocatalysts using Earth-abundant materials as economical alternatives to OER and OERHER. Transition metal oxides, sulfides, phosphates, carbon materials, selenides, and mixed metal complexes have been extensively studied and have good properties against OER and HER. However, most of these electrocatalysts require a higher overpotential than precious metal based catalysts, and improving their stability is still critical. Therefore, there is an urgent need to develop a low-cost, efficient alternative electrode structure with high activity and long-term stability to achieve efficient water splitting.

In the field of electrochemical applications, two main strategies are used to prepare electrodes. The first and most widely used technique involves the use of a catalyst in a powdered form. Typically, the electrodes are constructed by utilizing a slurry of an electrically active material, an electrical conductivity enhancer, and a binder on a conductive substrate. However, this approach is not without its drawbacks. The main disadvantage is the requirement for an electrically insulating adhesive, which can reduce the contact area between the electrolyte and the catalyst. This can lead to the blocking of the catalytic active site, resulting in high resistance and reduced electrocatalytic performance. In addition, the stability of the electrode is relatively poor, because the attached catalyst tends to peel away from the conductive substrate at high current density. The second major strategy for electrode preparation is the use of precious metal-based materials that are electrodeposited directly onto a conductive substrate, such as foam nickel, copper foil, carbon cloth or paper, FTO, stainless steel, and nickel foil. However, this approach is not without its limitations. It is difficult to precisely control the accessible space between the deposited active materials, so electrode performance weakens as the film thickness increases because the substrate cannot access the catalytic active site inside. In addition, the complexity and high cost of the method greatly hinder its practical application. Therefore, the development of cost-effective manufacturing techniques for three-dimensional (3D) electrodes is necessary for successful electrochemical applications.