Silver nanoparticles embedded in phosphorus and nitrogen-doped hierarchical hollow porous carbon for efficient supercapacitor and electrocatalytic water oxidation

Supercapacitor (SC) and oxygen evolution reaction (OER) require highly efficient multifunctional catalysts prepared from non-noble metals and heteroatoms. In this work, we have developed silver (Ag) decorated on phosphorus (P), nitrogen (N) -doped hollow porous carbon (HPC) prepared through hydrothermal followed by pyrolysis method. The prepared bifunctional electrocatalyst was studied through different characterization techniques. As-prepared HPC-UD, P-HPC-UD, and Ag@P-HPC-UD integrate high-level P-doping, large specific surface areas (up to 1452, 1247, and 528 m² g⁻¹), and hierarchical multipores of cross-linked micro and mesopore channels. As a result, the Ag and P modified the active sites and electronic structure of the HPC bifunctional catalyst, which is beneficial for the electrocatalytic process. As a result, the Ag@P-HPC-UD catalyst provides an outstanding specific capacitance value of 388 F g⁻¹ at 0.5 A g⁻¹ when used as a SC electrode. Furthermore, the Ag@P-HPC-UD electrocatalyst exhibited efficient OER behavior with a lower overpotential of 165 mV at 10 mA cm⁻² current density and a lower Tafel value of 55.46 mV dec⁻¹, which is remarkably superior to commercial RuO₂ electrocatalyst. Therefore, the Ag@P-HPC-UD electrocatalyst pathway for a new revolution in developing a highly impressive carbon-based electrode towards both SC and electrocatalytic OER performance.