Apple leaf waste yields green anti-corrosion solution for metals

GUWAHATI

Apple farm waste may soon help protect metal pipes, machinery, and infrastructure from corrosion.

An international research team led by Nagaland University (NU) has found a way to turn discarded apple leaves into a highly effective, eco-friendly corrosion inhibitor, offering up to 96.2% protection for copper in harsh chemical conditions.

The study, carried out in collaboration with the University of Science and Technology Beijing (USTB), shows that tiny carbon particles made from apple leaves can shield metals from corrosion without using toxic chemicals commonly employed in industry.

The authors of the study are Ambrish Singh of the NU’s Department of Chemistry and Yujie Qiang, Ye Zhang, Xinyang Liu, and Ying Jin of the USTB’s National Centre for Materials Service Safety. The former is a visiting professor at the USTB.

Their findings were published in the Journal of Alloys and Compounds, a leading international scientific journal.

Corrosion is a costly global problem, damaging pipelines, storage tanks, and industrial equipment in oil and gas, chemical processing, power generation, and other sectors. Conventional corrosion inhibitors often contain hazardous substances that pose risks to both the environment and human health.

The researchers found that their apple leaf-based solution, known as carbon quantum dots, performed exceptionally well even at low concentrations. In acidic conditions—where metals corrode faster—the material reduced copper corrosion by 94%, rising to 96.2% over time, levels considered highly promising for industrial use.

Explaining its practical value, Prof. Singh stated that industries operating in acidic environments face high maintenance costs and safety risks due to corrosion. “Biomass-based inhibitors like the apple-leaf material could extend the life of industrial equipment while being safer for workers and the environment,” he said.

Prof. Qiang added that the team used a green processing method to convert apple leaves into nanoscale carbon particles. These particles cling tightly to metal surfaces, forming a stable protective layer that blocks corrosive chemicals.

While the results are currently based on laboratory tests, the team plans to move toward pilot-scale trials and real-world applications, including combining the material with existing protective coatings

Calling the work a major step forward, Nagaland University Vice-Chancellor Jagadish Kumar Patnaik said the study shows how agricultural waste can be turned into a high-impact green technology. “Such innovations reduce dependence on toxic chemicals while addressing real-world industrial challenges,” he said.

Beyond corrosion protection, the research highlights the potential of waste-to-wealth solutions. By converting farm residue into valuable nanomaterials, the technology could support circular economy models and open up new income opportunities for farming communities.