Synthesis of silicon-based nano ceramic from e-waste

This study addresses the global recycling crisis for waste light bulbs, which have a recycling rate of only 5%. While traditional methods recover metals from LEDs and PCBs, small bulb enclosures are typically landfilled. The enclosure parts of waste LED bulbs contain approximately 50–60% high-quality polymer and waste glass bulbs consist of around 70% glass. These materials can serve as viable carbon and silicon precursors respectively for the innovative synthesis of valuable ceramic materials. This research presents a thermal transformation process for synthesizing nano silicon carbide (SiC) from end-of-life bulbs collected in New South Wales. LPD was identified as thermally stabilized polycarbonate via Fourier Transform Infrared Spectroscopy (FTIR), and Carbon, Hydrogen, Nitrogen, and Sulfur (CHNS) analysis showed a carbon content of 75.61%, making it an excellent carbon source. Similarly, X-ray Fluorescence (XRF) analysis of IGD revealed a SiO₂ content of 71.70%, providing a sufficient silicon source for SiC synthesis. Key synthesis parameters, including the size of LPD particles, mixing ratio of raw materials and reaction temperatures, were optimized to maximize purity and yield. It was found that when using coarsely ground LPD ranging from 0.5 to 2 mm, a higher SiC yield was achieved as it synchronized with IGD better in a timely manner. The mixing ratios ranged from 1:1 to 4:1 (LPD-to-IGD), with reaction temperatures varied between 750 °C and 1550 °C. XRD and FTIR analyses confirmed the synthesis of 92% pure SiC nanomaterials and 6.7% graphite under optimal conditions: coarsely ground LPD, a 4:1 mixing ratio, and a temperature of 1550 °C. Notably, the successful use of coarse LPD eliminates the need for energy-intensive pulverization into fine powders, significantly enhancing recycling efficiency. This reduction in mechanical pretreatment, coupled with high product purity, demonstrates a streamlined, energy-efficient pathway that confirms the scalability of this transformation process for industrial applications. FE-SEM imaging revealed two distinct SiC morphologies: nanoparticles and nanorods. This research demonstrates an innovative thermal transformation process that addresses the recycling crisis of waste lighting products by converting their overlooked enclosures into high-value nano SiC offering a sustainable solution to global recycling challenges while enabling the creation of materials with diverse industrial applications.