Eco-Friendly Biomass-Derived Porous Carbon Electrode for Simultaneous and Sensitive Detection of Catechol and Hydroquinone

A biomass-derived porous carbon (CSC–PA–800) was synthesized from discarded coconut shells through a green and sustainable KOH activation route combined with pre-carbonization and high-temperature carbonization. This work introduces a novel eco-friendly electrochemical sensing platform that integrates biomass valorization with high-performance detection of hydroquinone (HQ) and catechol (CC), two representative phenolic pollutants. Benefiting from its hierarchical porous framework and superior conductivity, CSC–PA–800 effectively facilitates analyte adsorption and electron transfer. Under optimized electrochemical conditions, the CSC–PA–800/glassy carbon electrode (GCE) sensor achieves a wide linear range (1–700 μM) and low detection limits (0.33 μM for HQ and 0.29 μM for CC) in 0.1 mol L⁻¹ PBS (pH 7.0), along with excellent repeatability (RSD < 1%), high selectivity and robust stability even in complex matrices. Furthermore, direct validation against the standard high-performance liquid chromatography (HPLC) method confirms its analytical accuracy, with recoveries of 95.38–104.64% in real tap and river water samples. These results underscore the unique contribution of this work in developing a low-cost, sustainable and high-sensitivity sensing platform, offering a scalable strategy for green analytical applications and real-world environmental monitoring.