Nano-biochar derived from bamboo biomass: A dual-functional material for electrochemical sensing of ferulic acid and adsorptive removal of surfactants in cosmetic wastewater

Nano-biochar, synthesized from bamboo biomass, was investigated as a dual-functional material for electrochemical sensing of ferulic acid in cosmetics and adsorptive removal of surfactants from cosmetic wastewater. The nano-biochar modified glassy carbon electrode (nano-biochar/GCE) exhibited excellent electrocatalytic activity towards ferulic acid oxidation, with a wide linear range (0.1–100 μM), low detection limit (30 nM), and good selectivity. The sensor was successfully applied for ferulic acid determination in real cosmetic samples, with recovery values ranging from 96.5 % to 102.8 %. Furthermore, the nano-biochar demonstrated high adsorption capacities for the removal of sodium dodecyl sulfate (SDS, 416.7 mg/g) and cetrimonium bromide (CTAB, 454.5 mg/g) from simulated cosmetic wastewater, following the Langmuir isotherm and pseudo-second-order kinetic models. Optimal removal efficiencies of 93.2 % for SDS and 95.8 % for CTAB were achieved under optimized conditions, highlighting the potential of nano-biochar for developing green analytical methods and wastewater treatment solutions in the cosmetic industry.