Dongre et al., in their research published in Electrochimica Acta, explored the potential of converting chilli plant waste into biochar-based electrocatalysts for green hydrogen production. The researchers produced biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More from discarded chilli plants and fruits through pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More, then enhanced it with iron or nickel for use in oxygen reduction reactions (ORR) and hydrogen evolution reactions (HER) in alkaline media. Their findings demonstrated that these biochar-based electrocatalysts exhibited significant electrocatalytic activity, offering a sustainable alternative to traditional precious metal catalysts.  

The study involved pyrolyzing chilli biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More at 600 °C and 800 °C, followed by activation with KOH and functionalization with iron(II) phthalocyanine for ORR or nickel nanopowder for HER. Electrochemical tests in alkaline media revealed promising performance. The Plant-Fe 800 electrocatalyst achieved an onset potential of 0.97 V and a half-wave potential of 0.87 V for ORR with minimal peroxide yield. For HER, the Chilli-Ni 800 electrocatalyst showed an overpotential of roughly 0.41 V.  

This research highlights the potential of utilizing waste biomass to create high-performing, cost-effective electrocatalysts for green hydrogen production. The use of earth-abundant materials like iron and nickel, combined with the valorization of waste biomass, makes this approach a significant step toward sustainable energy solutions.  

The abundance of chilli waste, with an estimated 18% of chilli crops discarded during harvest, makes it an attractive and readily available resource for sustainable applications. This approach not only reduces waste but also provides a valuable resource for the growing green hydrogen economy.  

Source: Dongre S, Zuccante G, Muhyuddin M, Lo Vecchio C, Baglio V, Berretti E, Lavacchi A, Shwetharani R, Balakrishna RG, Santoro C. Innovative biochar-based electrocatalysts from chilli plants and fruits for sustainable oxygen reduction and hydrogen evolution reactions. Electrochimica Acta. 2025 Mar 1;517:145763. https://doi.org/10.1016/j.electacta.2025.145763