TiO2-Doped Hydrochar Derived from Phoenix dactylifera: Synthesis and Electrocatalytic Performance for Alkaline Hydrogen Production

Abstract

Cost-effective, durable, and environmentally friendly electrocatalysts to be used for the alkaline hydrogen evolution reaction (HER) represent one of the key challenges facing green hydrogen generation. In this context, a TiO2-doped hydrochar derived from Phoenix dactylifera L. Deglet Nour (date pits) was synthesized and incorporated into a graphite-based electrode to improve HER performance in a 1 M KOH solution. Three TiO2 loadings (1, 3, and 6 wt%) were systematically studied and compared using electrochemical techniques to evaluate the influence of oxide incorporation on HER kinetics. In parallel, physicochemical characterization analyses were performed to acquire an in-depth understanding of the morphology, composition, and surface properties of biomass-derived carbonaceous materials and to establish correlations with their electrochemical behavior. The G/HC-3% TiO2 electrode exhibited the most pronounced electrocatalytic performance, with an overpotential of 194 mV at −10 mA·cm−2 and a Tafel slope of 67 mV·dec−1, indicating favorable interfacial charge transfer kinetics. The present work demonstrates that biomass-derived TiO2-doped hydrochar has significant potential as a sustainable and high-performance electrocatalyst in alkaline water electrolysis.