Microwave-assisted synthesis of Ni-doped carbon from bio-waste as a cost-effective electrocatalyst for effective and sustainable water electrolysis

The synthesis of cost-effective, easily synthesizable electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for advancement in sustainable hydrogen generation. The present study presents a facile synthesis of nickel-doped carbon (Ni@C) from bio-waste by microwave-assisted method as a highly efficient and sustainable electrocatalyst for the splitting of water. Physicochemical characterisation of the synthesised electrocatalyst confirms the effective incorporation of nickel in the carbon matrix, leading to the enhancement in electrocatalytically active sites. Evaluation of electrochemical parameters in 1 M KOH displays 280 mV and 180 mV overpotentials for OER and HER at 10 mA/cm 2 . Full cell electrolysis demonstrates the promising and excellent electrocatalytic behaviour at a potential of 1.65 V. Prolonged stability tests showed excellent durability for 100 h. The synthesised Ni@C electrocatalyst from bio-waste offers an environmentally friendly, easily synthesizable and cost-effective alternative for the production of hydrogen by water electrolysis. Integrating solar energy systems with electrolysis enables high-scale and sustainable hydrogen generation, leading towards the transformation into renewable energy technologies. • Sustainable energy production is achieved through easy synthesis from bio-waste materials. • Ni-doped carbon synthesised from bio-waste shows an OER overpotential of 280 mV. • For HER, the Ni-doped carbon demonstrates an overpotential of 180 mV at 10 mA/cm 2 . • The catalyst exhibits excellent stability during prolonged electrochemical testing. • Turnover frequency for OER is 0.1994 s −1 , highlighting effective catalytic activity for water splitting.