Controlled Nano-Dendritic Structuring of Porous Copper Films via Pulse Electrochemical Deposition and Additive Chemistry

Abstract

Porous copper films with nanoscale dendritic architectures are of growing interest in various advanced technology domains. These copper films form a three-dimensional porous network with internal surfaces that are covered with “Romanesco-like” dendritic features. This study investigates the influence of pulse-assisted electrodeposition and targeted additive chemistry on the dynamic hydrogen bubble templating process and the resulting film morphology. It is found that duty cycle modulation controls pore size and distribution. SEM analysis reveals that deposition with 25% duty cycle produces films with nearly 50% smaller pores and significantly thinner, shorter dendritic branches compared to continuous deposition. The addition of chloride ions induces a transition from multi-branched dendrites to elongated fractal structures, whereas citric acid promotes smaller, more uniformly distributed pores by modifying hydrogen bubble dynamics. When both additives are present, each retains its dominant influence, with chloride shaping branch structure and citric acid refining macro porosity, together producing a well-balanced porous network. The ability to selectively control both pore size and dendritic/fractal nanostructures provides a versatile pathway to engineer porous copper films with tailored architectures to achieve application-specific properties through a scalable electrodeposition process.