Nagaland–Beijing University study develops apple-leaf corrosion inhibitor

Guwahati, Jan 20: Researchers from the Nagaland University and the University of Science and Technology Beijing have demonstrated that carbon quantum dots derived from discarded apple leaves can deliver long-lasting and eco-friendly protection against metal corrosion, which is a persistent global industrial challenge.

The collaborative study, led by Prof Ambrish Singh of Nagaland University and Prof Yujie Qiang of the University of Science and Technology Beijing, showed that the newly developed apple-leaf carbon quantum dots (ACDs) can suppress copper corrosion in acidic environments with an inhibition efficiency of 94 per cent at low concentrations, improving to 96.2 per cent over longer exposure periods.

Such performance levels are considered highly promising for real-world industrial applications where metals are routinely exposed to harsh chemical conditions.

The findings of the research were published in the Journal of Alloys and Compounds, a leading peer-reviewed journal publishing research on the synthesis, structure, properties, and applications of metallic alloys and advanced compounds.

Beyond industrial benefits, the study also underscores the value of waste-to-wealth approaches.

Prof Singh said that the end applications of the research span several critical sectors. “In industries such as oil and gas, chemical processing, power generation, and wastewater treatment, acidic environments accelerate corrosion, driving up maintenance costs and safety risks. Biomass-derived inhibitors like apple-leaf ACDs could significantly extend the service life of pipelines, storage tanks, and industrial equipment, while reducing environmental and health hazards associated with conventional chemicals,” he said.

Speaking about the research, Prof Yujie Qiang said, “Using a green hydrothermal process, our research team converted apple leaves, an abundant agricultural waste, into nanoscale carbon particles doped with sulfur and nitrogen. These elements create multiple active sites that strongly adhere to metal surfaces”.

He continued, “Electrochemical tests confirmed that the ACDs form a compact, stable protective film on copper, effectively blocking corrosive ion transfer. Advanced theoretical modelling further revealed that specific nitrogen-containing groups play a key role in anchoring the protective layer to the metal surface.”

While the current results are based on laboratory-scale validation, the researchers plan to advance toward pilot-scale testing and real-world deployment, including integration with existing protective coatings.