Mass Deposition, Etching and Sputtering Effects of Low-Energy N ⁺ Ion Irradiation on Solid Fly Ash

Fly ash is an industrial waste created when coal is burned to generate electrical power. In the present study, we used low-energy nitrogen ion implantation on fly ash to improve its surface properties. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) were used to study the changes of physical and chemical properties of fly ash after N ⁺ ion implantation, and the mechanism of fly ash modified by ion implantation. In the optimal implantation with energy of 5 keV and dose of 15D ₀, the ion beam could effectively increase the specific surface area (approximately 150% increase) of the fly ash. Lots of scratches were generated in the surface of the fly ash after N ⁺ ion implantation, therefore it is good for enhancing the specific surface area. Experimental results show that the ion implantation could open the chemical bonds of Si-O, Si-Al and Al-O, and deposit nitrogen ions on the surface of fly ash.