The surface and bulk properties of NiOx/TiO2 samples prepared were characterized by different methods. BET surface area was measured by N2 adsorption at −196 °C (Quantachrome NOVA 1000). Prior to N2 physisorption, the samples were degassed under vacuum at 150 °C for 2 h. Structural properties were examined by powder X-ray diffraction (XRD) (Rigaku D/Max-2500 PC) with Cu Kα radiation and a Ni filter. XRD patterns were measured from 20° to 80° at a rate of 1° min−1. Diffuse reflection UV/vis spectra were recorded under ambient conditions (Shimadzu UV-3100PC) using BaSO4 matrix as background under ambient conditions. The spectra measured were converted to the absorption spectra by using the Kubelka–Munk function. X-ray photoelectron spectroscopy (JEOL JPS-9200) was used to examine the surface properties and all the binding energies were referenced with respect to the Ti 2p at 485.5 eV [17].