文摘
The structural, optical and electrical properties of molybdenum nanoparticles (Mo-NPs)-loaded anatase TiO2 were investigated using x-ray diffraction, UV–Vis diffuse reflectance, and Fourier transform infrared and complex impedance spectroscopy. x-ray diffraction showed that Mo-NPs incorporation induced a decrease in particle size from 30 nm to 21 nm of TiO2 and TiO2-Mo, respectively, producing a slight structure expansion. Mo-NPs dispersion resulted in a slight decrease in the optical band gap energy from 3.85 eV to 3.51 eV. Slight shifts towards higher wavelengths were attributed to the change in the acceptor capacity level induced by Mo-NPs. In addition, the ac impedance studies show the effect of Mo-NPs incorporation that appeared to be responsible for conductance of enhancement. The conduction mechanism is based on space charge-limited current via deep levels with different energy positions in the band gap. The temperature dependence of electrical properties showed that both capacitance and conductance of TiO2-Mo samples increased with increasing temperature. At low frequency, the relaxation phenomenon is related to the surface effect. The results will be beneficial to further developing titanium dioxide photo-catalysts.
