Preparation and characterization of ZnO–TiO2 films obtained by sol-gel method

Abstract

The sol-gel route has been applied to obtain ZnO-TiO 2 thin films. For comparison, pure TiO 2 and ZnO films are also prepared from the corresponding solutions. The films are deposited by a spin-coated method on silicon and glass substrates. Their structural and vibrational properties have been studied as a function of the annealing temperatures (400-750 °C). Pure ZnO films crystallize in a wurtzite modification at a relatively low temperature of 400 °C, whereas the mixed oxide films show predominantly amorphous structure at this temperature. XRD analysis shows that by increasing the annealing temperatures, the sol-gel Zn/Ti oxide films reveal a certain degree of crystallization and their structures are found to be mixtures of wurtzite ZnO, Zn 2 TiO 4 , anatase TiO 2 and amorphous fraction. The XRD analysis presumes that Zn 2 TiO 4 becomes a favored phase at the highest annealing temperature of 750 °C. The obtained thin films are uniform with no visual defects. The optical properties of ZnO-TiO 2 films have been compared with those of single component films (ZnO and TiO 2 ). The mixed oxide films present a high transparency with a slight decrease by increasing the annealing temperature.

Solar light induced rhodamine B degradation assisted by TiO2–Zn–Al LDH based photocatalysts

“…In this region a broad shoulder is detected in sample IM_ZnAl_3Ti indicating a small TiO 2 amount, confirmed by the XRD analysis [20]. The absorption peak (1089 cm À1 ) only present in sample IM_ZnAl_3Ti is related to C-OH groups and can be attributed to the axial stretching of C-O, coupled to the stretching of an adjacent C-C bond [53]. According to literature, all absorptionvibration bands that are detected in the range of 800-400 cm À1 usually are assigned to vibration bands of [54].…”

Coordination chemistry of titanium and zinc in Ti(1−x)Zn2xO2 (0 ≤x≤ 1) ultrathin films grown by DC reactive magnetron sputtering

“…26 The mechanisms driving the formation of three different zinc titanate compounds in the ZnO-TiO 2 system, namely, zinc ortho-titanate Zn 2 TiO 4 (cubic inverse spinel crystal structure with a unit cell a = 0.846 nm), zinc meta-titanate ZnTiO 3 (either cubic inverse defect spinel, a = 0.840 nm or hexagonal ilmenite structure, a = 0.507 nm) and Zn 2 Ti 3 O 8 (cubic inverse defect spinel, a = 0.843 nm) are still under debate. [27][28][29] Despite the extensive studies performed on the individual TZO and ZnO-TiO 2 systems in areas such as photovoltaics, photocatalysis or optoelectronics, there is a lack of systematic work to fully understand Ti incorporation into the ZnO structure either as a dopant or to form a mixed oxide. In particular, one of the current technological challenges is the elucidation of such mechanism for nanostructured and ultrathin films due to the size-dependent electronic and optical properties of these semiconductor materials, as discussed in ref.…”

Physico-Chemical Characterization and Interfacial Electrochemical Properties of Nanoparticles of Anatase-TiO2 Prepared by the Sol-Gel Method

“…In fact, the presence of a permanent hydration layer on the surface of particles increases considerably the stability of the studied hydrosol 17 . The ionic adsorption on the prepared titanium oxide is studied in pH superior to the pzc in the presence of alkaline cations Li + , Na + and K + and with pH inferior to the pzc in the presence of halides anions F -, Cl -and I -.…”