A Review of the Design and Synthesis of (Electro)chemically Induced Three-dimensional Nanoporous Copper: A Strategic Element for CO ₂ Electro-Reduction and Self-Sanitization Applications

The catalytic and self-sanitizing properties of copper (Cu) can be significantly enhanced by inducing nanoporosity into the structure. In this review, we first briefly introduce electrocatalysis and biocidal applications of Cu, with the discussion on electrocatalysis geared toward the electrochemical reduction of carbon dioxide to value-added fuels and chemicals. Second, the underlying mechanisms for the enhancement of the electrocatalytic and biocidal properties by means of morphology manipulation are discussed, followed by a review of chemical and electrochemical techniques used to synthesize nanoporous Cu. Additionally, the parameters that enable fine-tuning of the sizes and structures of the resulting porosity are outlined, including the composition and crystal structure of the precursors, along with electrochemical factors such as electrolyte, applied overpotential, and treatment time. This review elucidates the crucial role that the nanostructure of Cu plays in augmenting the electrocatalytic efficiency and self-sterilizing attributes of Cu. Moreover, it provides insights into and discusses the challenges in designing advanced functional nanomaterials and synthesizing well-controlled morphologies essential for sustainable electrocatalysis and antimicrobial applications in diverse fields.