Apple leaves to anti-rust: Nagaland University unveils green shield against metal corrosion

Guwahati: What if discarded apple leaves could protect industrial metals from corrosion? An international research team led by Nagaland University, in collaboration with the University of Science and Technology Beijing, has shown that agricultural waste can be transformed into a powerful, eco-friendly corrosion inhibitor, challenging the dominance of toxic chemicals widely used across infrastructure and manufacturing sectors.

The study demonstrates that carbon quantum dots derived from apple leaves can suppress copper corrosion in acidic environments with remarkable efficiency, 94.0% at low concentrations, rising to 96.2% with longer exposure. Such performance places the material among the most promising green alternatives for real-world industrial use, where corrosion leads to massive economic losses and safety risks.

The collaborative research, led by Prof. Ambrish Singh of Nagaland University and Prof. Yujie Qiang of the University of Science and Technology Beijing, has been published in the prestigious Journal of Alloys and Compounds, a leading peer-reviewed journal in advanced materials science.

Congratulating the team, Prof. Jagadish Kumar Patnaik, Vice-Chancellor of Nagaland University, said:
“This work shows how agricultural waste can be turned into a high-performance, eco-friendly corrosion inhibitor with up to 96.2% protection for copper. The Indo–China collaboration reflects our commitment to sustainable, high-impact science that addresses real industrial challenges while reducing dependence on hazardous chemicals. Such innovations strengthen Nagaland University’s role in advancing green technologies for infrastructure and manufacturing.”

Beyond industrial relevance, the research highlights the potential of waste-to-wealth innovation. By converting apple-leaf residue into high-value nanomaterials, the study aligns with circular economy principles and opens up future income opportunities for farming communities through value-added biomass utilisation.

Explaining the practical implications, Prof. Ambrish Singh, Department of Chemistry, Nagaland University, and Visiting Professor at the University of Science and Technology Beijing, said:
“Industries such as oil and gas, chemical processing, power generation, and wastewater treatment routinely operate in acidic environments that accelerate corrosion. Biomass-derived inhibitors like apple-leaf carbon quantum dots can significantly extend the lifespan of pipelines, storage tanks, and industrial equipment—while minimising environmental and health hazards.”

Detailing the science behind the breakthrough, Prof. Yujie Qiang, National Center for Materials Service Safety, University of Science and Technology Beijing, noted:
“Using a green hydrothermal process, we converted apple leaves into nanoscale carbon particles doped with sulfur and nitrogen. These elements create multiple active sites that bond strongly with metal surfaces. Electrochemical tests confirmed that the material forms a compact, stable protective film on copper, effectively blocking corrosive ion transfer. Advanced theoretical modelling further showed that nitrogen-containing groups play a crucial role in anchoring this protective layer.”

While the results are currently validated at the laboratory scale, the researchers are now working toward pilot-scale testing and real-world deployment, including integration with existing industrial protective coatings.

The study positions Nagaland University at the forefront of sustainable corrosion science, underscoring how international collaboration and environmentally responsible innovation can address global materials challenges.