Property–Performance Relationship of Waste Floral Foam-Derived Nanoporous Carbon as Metal-Free Oxygen Evolution Reaction and Hydrogen Evolution Reaction Electrocatalyst: Implications of N and S Doping

Abstract

Designing electrocatalysts with high-performance potential requires a thorough investigation of the relationships between property changes and electrocatalytic activity. This study compares the effect of N-doping and N, S-codoping on the properties of waste floral foam derived pristine nanoporous carbon to enhance electrocatalytic activity. N, S-codoping modulates the textural, structural, and chemical properties of pristine nanoporous carbon that are preferable to oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance. N, S-codoped nanoporous carbon having a large surface area (1231 m² g⁻¹), higher content of defects, OH−, CO, and pyridinic N exhibits superior OER and HER activity with overpotentials 290 and −180 mV, respectively at 10 mA cm⁻², emphasizing the synergetic effect of dual atoms nitrogen (N) and sulfur (S) in enhancing electrocatalytic performance. The work proposed here presents the implementation of “waste-to-energy” through repurposing of waste floral foam into N, S-codoped nanoporous carbon as a metal-free bifunctional electrocatalyst for OER and HER.