Mechanistic Evaluation of Single-Crystalline Aluminum Nitride Nanowire Synthesis from Plastic Waste

One-dimensional aluminum nitride (AlN) nanowires are of great interest because of their unique large band gap and low dimensionality, which make them promising for novel molecular electronic devices and functional composites. However, commercialization is still restricted by the high manufacturing cost and feedstock requirements. Although the feasibility of the synthesis of AlN nanowires from metallized plastic packaging waste has been reported in the previous work, essential information on the synthetic mechanism and nanowire growth characteristics remains unclear. In this work, we have characterized the intermediate solid products to show the initial direct nitridation of the aluminum foil, followed by the formation of aluminum oxide (Al2O3), aluminum carbide (Al4C3), and aluminum monoxycarbide (Al2OC) that are ultimately transformed into AlN in a high yield. This mechanism takes place under an atmosphere of reducing gasses evolved during the decomposition of the plastic components in the waste. The growth of AlN nanowires was monitored during nucleation, crystal growth, and propagation, and finally, conversion from polycrystalline to single-crystalline AlN with an aspect ratio greater than 100 was required for device applications.

Automated summary

This study elucidates the mechanism of synthesizing AlN nanowires from plastic packaging waste, showing the direct nitridation process of aluminum foil and highlighting the growth characteristics of the nanowires. The research provides crucial insights into the intermediate products and the growth of nanowires, offering valuable references for future device applications.