Nitrogen- and Sulfur-Rich Activated Carbon Derived from Biomass Waste as Adsorption Probe for Pb2+ Ions

In the present work, nitrogen (N)- and sulfur (S)-rich activated carbon were prepared from biomass waste pine needles through activation by conc. H2SO4 followed by its thermal annealing. The prepared activated carbon material was analyzed by HR-TEM, XRD, XPS, and FT-IR techniques. XPS and FT-IR analyses confirm different functionalities present in the sample along with their percentage. HR-TEM and XRD analysis confirmed that the sample is highly amorphous with small graphitic flakes embedded in it. The prepared material was designated as NS-PN-AC, exhibiting remarkable performance for extremely sensitive detection of Pb2+ ions by UV-Vis spectroscopy. The UV-Vis results show that the prepared material has a strong absorption peak at 0.2042 & Aring;. However, the presence of Pb2+ significantly reduced the intensity of the absorption. A limit of detection (LOD) of 7.7 ppm was reached in the presence of Pb2+ concentration ranging from 0 to 10 ppm. These findings demonstrated the viability of developing sensors for detecting and removing lead (II) ions using inexpensive precursors.