Utilization of algal biomass-derived carbon in the alkaline water electrolysis for hydrogen production

Abstract

The increasing focus on eco-friendly hydrogen production from biomass has led to the exploration of novel approaches for pilot-scale hydrogen generation. This study explores a new approach for the hydrogen evolution reaction (HER) in alkaline water electrolysis using biomass-derived carbon catalysts. Biochar morphology and composition were characterized by FESEM-EDS, while structural properties were examined using Raman and XRD. The hydrogen-producing electrode (HPE) was fabricated by coating algal biochar on nickel foam (GA@NF), and its electrochemical performance was assessed through LSV, CV, and EIS. GA@NF demonstrated superior performance among the tested HPEs, with a low overpotential of −126 mV at a current density of 100 mA/cm² and a Tafel slope of 84 mV/dec. Furthermore, MA@NF and CO@NF exhibited overpotentials of −202 and −457 mV, and Tafel slopes of 228 and 141 mV/dec, respectively. At an input voltage of 2.5 V, the average hydrogen production rates over 15 min were 52.240, 43.803, and 39.250 mg/s for GA@NF, MA@NF, and CO@NF, respectively. Extending the test to 30 min, GA@NF reached a maximum production rate of 555.529 mg/s, which is 10.63 times higher than the previous study (30 min). These results highlight GA@NF's superior electrochemical behavior and effectiveness in enhancing HER during alkaline water electrolysis.