Synthesis of Fe-Ni-doped graphene electrocatalyst for hydrogen evolution reaction via UV-assisted phytochemical reduction using Andrographis paniculata extract

Abstract

Electrocatalytic water-splitting is a promising method for hydrogen production. Fe-Ni-doped graphene (Fe-Ni-G) for hydrogen evolution reaction (HER) was synthesized via UV-assisted phytochemical reduction using Andrographis paniculata extract (AP). The impact of AP mass loading and UV irradiation time on Fe-Ni-G's electrocatalytic activity towards HER was explored. FTIR and SEM-EDX characterizations confirmed the successful reduction and incorporation of Fe and Ni on the graphene surface. The onset potential for HER on Fe-Ni-G ranged from – 0.632 V to – 0.548 V (vs. SHE). Optimizing AP mass loading and UV time yielded the best results with 5 g AP and 1 h UV irradiation producing the highest H2 gas evolution (~3.4 mL) after 1 h electrolysis in 0.5 M H2SO4 at 3 V. This study suggests a cost-effective and eco-friendly route for preparing HER electrocatalysts through UV-assisted phytochemical reduction using AP as a reducing agent.

Keywords

• phytochemical reduction
• electrocatalyst
• hydrogen evolution reaction
• green chemistry
• graphene