Pantnagar Journal of Research

Abstract

Improper disposal of agricultural residues and the proliferation of the invasive weed Parthenium hysterophorus pose significant environmental threats. This study investigates the preparation and adsorbent properties of carbon dots (CDs) derived from Parthenium hysterophorus shoot biochar (PHSBC) via bottomup approach. The CDs were produced by varying PHSBC dosage, magnetic stirring and centrifugation time, followed by vacuum filtration. Characterization results revealed that the CDs possess a slightly alkaline nature and high electrical conductivity, facilitating the attraction of cationic pollutants. Solid yields ranging from 6.97% to 31.9% were obtained CDs were prepared from more centrifugation time at low PHSBC dosage and was identified as optimal for preparing CDs with high adsorptive qualities as per the results obtained from proximate analysis. Statistical analysis (one way ANOVA and posthoc Tukey tests) confirmed that centrifugation time was the primary determinant of elemental composition (p < 0.05), significantly enhancing carbonization. FTIR analysis confirmed that the surface functional groups remained chemically stable for all CDs prepared. The sample B1M4C3, B2M1C3 and B3M4C3 emerged as the superior adsorbents exhibiting highest predicted surface area. This research study demonstrates that while the chemical affinity of CDs is fixed by their precursor, their adsorptive capacity is highly tunable through physical conditions as their preparation time. This study provides a scalable, “green” alternative for contributing to the “Waste to Wealth” (WtW) paradigm and aligning with United Nations Sustainable Development Goals 6, 9, 12, and 13.