Efficient bifunctional metal-free phosphorus-modified nitrogen-doped carbon toward high-performance acidic oxygen...

Developing bifunctional electrocatalytic materials for the oxygen evolution reaction (OER) and supercapacitors in acidic environments is pivotal for advancing energy conversion and storage technologies. However, this task remains challenging owing to the corrosive environment and sluggish reaction kinetics. In this study, we report a novel self-assembly in situ doping strategy to develop a metal-free phosphorus-modified nitrogen-doped carbon (P-NG) bifunctional material. The synthesis involves phytic acid-induced polymerization and carbonization, which successfully incorporates phosphorus into the carbon matrix and creates an uneven charge distribution. This unique structure efficiently facilitates electron transport, resulting in advanced performance for both OER and supercapacitors. More importantly, mechanistic insights reveal that the induced PC moieties act as key active sites for the acidic OER. Consequently, the P-NG exhibits exceptional OER performance, surpassing most carbon-based electrocatalysts and rivaling commercial RuO₂. When integrated into a proton exchange membrane (PEM) water electrolyzer, it enables a low operating voltage. Concurrently, it also shows superior energy storage capacity compared with previously reported materials. This study provides a viable design paradigm for multifunctional carbon-based materials for energy applications.