The carbon encapsulation of nanosized Pt cathode catalysts for ultra-low Pt loading proton exchange membrane fuel cells is an effective approach to enhance their stability and catalytic activity for the oxygen reduction reaction (ORR). However, the synthesis procedures for such a catalyst are delicate and cumbersome. Therefore, it is difficult to use such procedures for mass production. Here, we have developed a facile strategy for synthesizing carbon-encapsulated Pt nanoparticles supported on carbon nanofibers (CNFs) using a Pt–aniline complex. This strategy begins with applying a wet Pt–aniline complex coating to CNFs. Heat-treating the coated CNFs produced 3–4 nm-sized Pt nanoparticles that were uniformly coated with a layer of carbon on the CNF surface (Pt@CS/CNF). Compared to other carbon-coated Pt catalysts, the stability and catalytic activity of Pt@CS/CNF for the ORR are high owing to the robustness of the carbon shells that secure the Pt nanoparticles. In a unit cell test, the performance of Pt@CS/CNF heat-treated at 900 °C was almost maintained for 30 000 accelerated stability test cycles, showing a negligible voltage loss at an operating current density of 0.8 A cm⁻².

Cu electrodeposition and superfilling in the presence of organic additives have been widely researched. Nowadays, the reduction of interconnection dimensions raises issues, such as the reduction of electrical property and the difficulty of superfilling narrow features. Superfilling results from the competitive adsorption of organic additives, and the changes in their surface coverage. Therefore, modification of the adsorption state can improve the superfilling performance. Since anodic potential is applied during the pulse-reverse electrodeposition, it has the potential to considerably affect the adsorption of organic additives. In this research, the impacts of process parameters of pulse-reverse electrodeposition, such as deposition/anodic potentials and anodic time, on the competitive adsorption between PEG-Cl⁻ and SPS are studied. It is confirmed that the anodic step promotes the displacement of PEG-Cl⁻ by SPS at the early stage of electrodeposition, and it is intensified with more positive potential and longer anodic time.