Stefan Mitrović

Nickel‐based catalysts are among the most promising materials for electrocatalytic water splitting, particularly for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. Their abundance, cost‐effectiveness, and tunable electrochemical properties make them attractive alternatives to precious metal catalysts. This review provides a comprehensive analysis of the advancements in nickel‐based catalysts, including pure nickel, alloys, oxides, hydroxides, and spinels, emphasizing their synthesis methods, structural properties, and electrocatalytic performance. Recent nanostructuring, doping, and hybridization innovations with conductive supports have significantly enhanced catalytic activity, stability, and efficiency. Despite notable progress, challenges remain in improving long‐term durability, minimizing surface degradation, and scaling up production for industrial applications. Addressing these limitations through advanced catalyst design, in situ characterization, and integration with renewable energy sources will be crucial for widely adopting nickel‐based catalysts in sustainable hydrogen production. This review highlights the key developments and future directions in the field, underscoring the role of nickel‐based materials in enabling the hydrogen economy and global decarbonization efforts.

This paper explores the feasibility and efficacy of employing whole CPU (Central Processing Unit) recycling as a sustainable source of metals for catalyst coatings in the Hydrogen Evolution Reaction (HER). With the escalating global issue of electronic waste (e-waste), repurposing discarded CPUs offers a promising avenue for metal recovery and utilization. Through systematic experimentation, CPU preparation technique was evaluated for formation of electrode catalytic layer and the kinetics of HER in alkaline media. The resulting electrodeposited cathode was assessed for electrocatalytic efficiency. Our findings highlight the potential of utilizing e-waste-derived metals, particularly gold and copper, as effective catalyst coatings for HER, thus contributing to sustainable metal recovery and utilization strategies.

This study explores the production of activated carbon (AC) from lemon peel, an agricultural waste, using phosphoric acid activation, presenting a sustainable alternative to conventional AC derived from fossil fuels. The processed lemon peel AC exhibited promising electrochemical properties suitable for supercapacitors, including high specific capacitance of 138.9 F/g at a scan rate of 20 mV/s and excellent stability in an alkaline environment. These findings demonstrate the potential of bio-waste as a cost-effective and environmentally friendly precursor for AC production. This approach not only supports waste minimization but also contributes to sustainable resource utilization in the field of energy storage.