Vacancy Defect Engineering via Electrodeposition: A Review and Perspectives for Electro- and Photocatalysis

Defect engineering is an innovative approach for tailoring the properties and catalytic performance of electrodes across a range of applications, leveraging their remarkable redox capabilities and physicochemical attributes. Structural defects create coordinatively unsaturated sites that function as highly active centers, facilitating reactant adsorption and activation in catalytic reactions. By modulating the type and quantity of defects within electrodes, the physicochemical and catalytic properties of materials can be effectively adjusted, simplifying the design process. The electrodeposition technique has garnered considerable interest for synthesizing catalysts through vacancy engineering. This well-established method for producing electrode materials allows for precise control over film thickness, surface morphology and, homogeneity, while offering a cost-effective and scalable route through manipulating deposition rates, precursor ratios, and medium parameters. However, a comprehensive review of vacancy defect engineering within electrodeposition techniques is currently lacking. In this review, we begin by outlining the basic concepts of electrodeposition and then summarize the different strategies used to introduce various types of vacancy defects, either through electrodeposition alone or in combination with complementary techniques. We then categorizing the types of material defects and discussing their impacts on the surface characteristics, electronic structure, catalytic activity, selectivity, and stability of electrodes. Furthermore, we critically analyze the role of vacancy defects in optimizing electronic structures, enhancing charge separation, and improving surface reaction kinetics. Through strategic defect engineering, electrocatalysts synthesized via electrodeposition can achieve distinctive catalytic properties and enhance their effectiveness. This review also offers guidance for selecting appropriate synthesis strategies within electrodeposition to optimize electrocatalytic efficiency. Finally, key challenges and future directions in vacancy defect engineering are discussed, providing a roadmap for designing efficient electrode materials with tunable vacancy characteristics. Despite current challenges, the design and fabrication of catalysts featuring well-controlled vacancies represent a promising avenue for advancing electrocatalytic technologies.