Mesopore-Depth Optimization in Mesoporous Gold Films for SF ₆ Electroreduction

We report a bottom-up approach to fabricating mesoporous gold (MPG) films using a bicontinuous microemulsion (BME) as a soft template for electrodeposition. This method enables the production of MPG films with ligament and mesopore diameters in the range of 30–50 nm, while allowing the film thickness to be tuned up to 1.8 μm. The roughness factor increased proportionally with film thickness, indicating uniform mesoporosity throughout the films. Because SF6 is one of the most persistent greenhouse gases, its electroreduction demands rational catalyst design. Our systematic investigation revealed that submicrometer control of mesopore depth is essential for maximizing electrochemical SF6 reduction performance, whereas further increases in thickness do not yield additional improvement.