A novel integrated circular economy approach in green synthesis of copper oxide nanoparticles from waste printed circuit boards and utilization of its residue for preparation of carbon engulfed nano polymer membrane

Electronic waste is a major threat to our environment. Handling and recycling of electronic waste towards the circular economy is a tedious process. Researchers are trying to enhance the existing recycling techniques to improvise the process for better efficiency and also to result in lower by-products. Pre-treatment of Waste Printed Circuit Board (WPCB) using sodium hydroxide solution as solvent under autoclaving conditions results in 100% of epoxy removal efficiency. Further, the selective leaching process of WPCB utilizing ammonium chloride solution and ammonia buffer solution, reduced with the help of Cathantharaus roseus plant leaf extract, clears the way for the generation of copper oxide nanoparticles. Synthesized nanoparticles are separated by repeated centrifugation at 10000 rpm for 30 min using sterile distilled water, then drying it in a hot air oven for 2 h. Samples are characterized using HRTEM and FESEM-EDX. The residual thermoset of WPCB is muffle treated at 550 degrees C for 3 h to get desired carbon forms and is characterized using Raman spectroscopy, FESEM-EDX. Grounded carbon forms are utilized for synthesizing carbon-engulfed polyvinyl alcohol (PVA) membrane using electro-spinning, which finds its application in dye removal. Synthesized nano-sized polymer membrane is characterized using TGA, FESEM-EDX, FTIR and tensile strength through Universal Testing Machine.