Conversion of Plastic Polymeric Wastes into Carbon Dots: A Sustainable Approach

Abstract

Plastic polymeric materials pose significant waste and environmental hazards, creating widespread environmental concerns. In this study, carbon dots (CDs) were synthesized from plastic wastes by hydrothermal carbonization technique and their reactions and morphology were investigated. The prepared carbon dots were characterized using the UV-Visible spectrophotometer, Fourier Transform Infrared (FTIR) Spectrophotometer, Energy Dispersive X-ray spectrophotometer (EDX), Powder X-ray Diffraction (PXRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). UV-Visible spectrum revealed that carbon dot showed maximum absorption peak at 286 nm. FTIR analysis indicated the presence of reactive functional groups at peak bands of 3399 cm^-1, 2975 cm^-1, 1743 cm^-1, 1652 cm^-1, 1165 cm^-1 representing -OH Stretch of alcohol, -C-H Stretch of alcohol, C=O Stretch of carbonyl, N-H bending of amide and C-O stretch of ether. EDX result provided the elemental composition and percentage distribution of the elements in the carbon dot, showing C (89.65%) and O (10.35%) respectively depicting its successful synthesis. SEM images showed that the synthesized carbon dots had a spherical morphology with porous surface, while TEM analysis revealed an average particle size of 3.54 nm. PXRD spectra confirmed that the carbon dots have band peaks at the miller index of (002) and (101) with broad and non-intense peaks which characterized them to contain no crystalline substances.