Tuning active sites of N-doped porous carbon catalysts derived from vinasse for high-performance electrochemical sensing

N-doped biomass-derived porous carbon was synthesized by the pyrolysis of sugarcane-vinasse to develop a novel metal-free catalyst in electrochemical sensing. Vinasse samples were subjected to different pyrolysis temperatures under nitrogen flow to investigate the effect of the pyrolysis temperature on the physical properties of the biomass-derived products. The XPS results displayed that as-pyrolyzed samples contain N atoms with an atomic ratio of 3.02%. While a low surface area of 1.5 m²/g was measured from the sample pyrolyzed at 600 °C, the increase in the temperature yielded a large surface area of 620 m²/g. Additional heat treatment was implemented to tailor N-binding sites. Samples were then used as electroactive catalysts for hydrogen peroxide (H₂O₂) electrochemical sensing. Vinasse-P-10@N-based sensors showed much-improved sensor performance in a linear range of 0.03–12 mM with a high sensitivity of 208.97 µA mM⁻¹ cm⁻².