Nanophase Changes in Nickel Doped Titania Composites by Thermal Treatment and Photocatalytic Destruction of NO(x).

Abstract

This study investigated the influence of Ni doping and thermal treatment (600, 800 degrees and 1000 degrees C) on the physiochemical properties of a commercially available low cost KA100 TiO2. Ni containing KA100 samples were prepared with different loading of Ni (3%, 6% and 9% wt to KA100) and subjected to heat treatement at 600 degrees, 800 degrees and 1000 degrees C. The as-prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Diffuse reflection UV-Visible spectroscopy and Raman spectroscopy and nitrogen-adsorption-desorption measurements to observe the nanophase changes in the particle characteristics following Ni modification and thermal treatment. The results show that the Ni atom entered the TiO2 lattice structure upon heat treatment at 800 degrees C and 1000 degrees C influencing the anatase-rutile phase transformation. The TiO2 powders after heat treatment had a bimodal pore-size distribution as the temperature of the heat treatment increased. In addition, the anatase crystallite size and average pore sizes increased. Photodegradation of NO(x) was investigated using the Ni doped KA100 as a photocatalyst. Modification of KA100 with nickel and heat treatment up to 1000 degrees C enhanced the photocatalysis for the degradation of NO(x). Typically, KA100 modified with 6% Ni and heat treated to 1000 degrees C exhibited excellent NO(x) removal activity.