Mesoporous TiO ₂ hollow spherical nanostructures with high surface areas were successfully prepared using a microwave method. The prepared hollow spheres had a size range between 200 and 500 nm. The spheres consisted of numerous smaller TiO ₂ nanoparticles with an average diameter of 8 nm. The particles had an essentially mesoporous structure, with a pore size in the range of 2–50 nm. The results confirmed that the synthesised of anatase TiO ₂ nanoparticles with specific surface area approximately 172.3 m ² g ⁻¹ . The effect of ultraviolet and visible light irradiation and catalyst dosage on the TiO ₂ photocatalytic activity was studied by measuring the degradation rate of methylene blue. The maximum dye degradation performances with low catalyst loading (30 mg) were 99% and 63.4% using the same duration of ultraviolet and visible light irradiation, respectively (120 min).

In this work, TiO₂ nanorods synthesized using polyol solvothermal method. The prepared sample was studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV-Vis spectroscopy. XRD pattern shows that the prepared sample has pure TiO₂ with anatase phase, while SEM images reveals the formation of TiO₂ in nanorods with an average lengths and diameters about 1049 nm and 165 nm, respectively. The energy gap (E_g) of the prepared TiO₂ was found to be 3.10 eV.

High aspect ratio ZnO nanorods with controlled diameters and lengths have been successfully prepared. The seed-mediated growth method was used to prepare the samples. An extensive investigation on the performance of the ethanol gas sensor based on ZnO nanorods has been reported. The effects of dimensions on gas-sensing performance and operating temperatures have evidently been discussed. This paper shows that the response to gas has a strong dependence on ZnO nanorod dimensions.

Recently, TiO2/multi-walled carbon nanotube (MWCNT) hybrid nanocatalysts have been a subject of high interest due to their excellent structures, large surface areas and peculiar optical properties, which enhance their photocatalytic performance. In this work, a modified microwave technique was used to rapidly synthesise a TiO2/MWCNT nanocatalyst with a large surface area. X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller measurements were used to characterise the structure, morphology and the surface area of the sample. The photocatalytic activity of the hybrid nanocatalysts was evaluated through a comparison of the degradation of methylene blue dye under irradiation with ultraviolet and visible light. The results showed that the TiO2/MWCNT hybrid nanocatalysts degraded 34.9% of the methylene blue (MB) under irradiation with ultraviolet light, whereas 96.3% of the MB was degraded under irradiation with visible light.

In this study, a grafted polymer (GP) with ZnO nanoparticles (GP/ZnO NPs) was attached on the surface of glassy carbon electrode (GCE), in order to produce a new modified electrode (GP/ZnO NPs-GCE)....