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Using butyl titanate as titanium source, lanthanum nitrate as a source of lanthanum, iron nitrate as an iron source, the titanium dioxide powder of lanthanum/iron single-doped and co-doped were synthesized by the sol-gel combustion method. The doped TiO2 powders were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (IR), and the photocatalytic activity was studied with methyl blue, methylene chloride and formaldehyde as the source of pollution. The results show that we obtain TiO2 anatase when the heat treatment temperature was 450 °C. When the amount of doped Lanthanum and iron were 0.5%, the grain size of the powder was significantly reduced and the degradation efficiency for organic pollutions was highly improved compared with pure TiO2.

The present work was dedicated to the tailored synthesis of TiO2 nanopowders doped with nitrogen (called TiO2−xNx ) for the photocatalytic degradation of methyl orange. In particular, the systems were synthesized by a sol-gel combustion route starting from nitric acid and tetrabutyl titanate (Ti (OC4H9)4) as raw materials. The powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), suggesting that anatase phase is obtained at pH value of 4-6 and the heat-treated temperatures as low as 425°C. The photocatalytic activities of the N-doped TiO2 nanopowders were monitored from the results of the degradation rate of methyl orange (MO) under solar light irradiation. The dependence of dye degradation rate on photocatalyst amount and initial pH was investigated. Under solar light irradiation, the TiO2 doped with 30% N exhibited the highest photocatalytic reactivity, which could be attributed to the structure of the combustion-synthesized catalyst and the change of the bandgap induced by nitrogen inclusion.

Lead-free piezoelectric ceramics (1-x)Na0.5Bi0.5TiO3-xBaTiO3(x=0.04, 0.06, 0.08) was synthesized via sol–gel combustion method. Structural analysis was performed by using X-ray diffraction (XRD). The structural morphology of the nanoparticles was studied using scanning electron microscopy (SEM). The ceramics show a rhombohedral-tetragonal morphotropic phase boundary (MPB) in the range of x =0.04-0.08, which makes ceramics having superior dielectric and piezoelectric properties. There is a decrease of the grain size with increasing BT concentration, suggesting that dissolving BT into NBT inhibits the grain growth. And the multi-peak fitting result shows lattice constants of NBT have increased with the BT doped into NBT. Belong to the ionic polarization relaxation type, the low temperature dielectric anomalous peak shift towards a high temperature and the high temperature dielectric anomalous peak shift towards a lower temperature showed by the dielectric-temperature spectrum. Dielectric-temperature spectrum further determines that (1-x)NBT-xBT ceramics are relaxation ferroelectrics, and join BT makes the Curie temperature decreasing about 21 to 24°C. High piezoelectric properties with d33=148pC/N are observed in NBT-BT0.06.