Mesopore-Depth Optimization in Mesoporous Gold Films for SF₆ 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.