Titanium (IV) isopropoxide (TTIP) was used to synthesize GO/TiO2 thin films using a sol-gel spin-coating method onto a glass substrate, undergoing an heat tretment at 350 °C. Several amounts of graphene oxide (GO) (0-20mg) were weighed into a sol solution of TiO2 to produce GO/TiO2 thin films. The thin film samples were characterized by X-ray diffraction (XRD) to analyze the samples' phase and by scanning electron microscopy (SEM) to analyze the samples' microstructure. Physical testing such as water contact angle (WCA) was analyzed using an optical microscope with J-Image software. In contrast, the optical band gap and photodegradation of methylene blue under sunlight irradiation of the thin film was analyzed using UV-VIS spectrophotometry. GO5 thin film sample showed low-intensity anatase phase formation, where the microstructure revealed a larger surface area with the addition of GO. WCA reveals that GO/TiO2 thin film exhibits super hydrophilic properties where the angle decreases from 37.83° to 4.11°. The optical result shows that GO has improved the absorption edges by expanding into visible regions. Moreover, due to the existence of GO 3.30 eV band gap energy of TiO2 decreases from to 3.18 eV obtained by GO5. The improved adsorption edge allows Ti 3+ , O2 and interstitial states to be formed in low valence states with energy underneath than in the TiO2 band gap. Therefore, the photodegradation of methylene blue (MB) dye increases from 48 % to 59 % in the GO/TiO2 thin film.

Graphene oxide/TiO2 (GO/TiO2) thin films works as self-cleaning device have been developed in various method onto selected substrates. It was noticeable that graphene oxide is the best form in the group of graphene family. Under self-cleaning application, the wettability test and electroconductivity of the sample was the main characteristic for self-coating study. As planned, by addition of graphene to TiO2 films produce a highly conductivity, transparent and produced promising enhanced photocatalytic activities. Moreover, superhydrophilic properties of GO/TiO2 film surface film exhibits more as compared to TiO2 film only within a short period of time. Thus under this finding, the photocatalytic activity of GO/TiO2 films will be enhance as a result of improve charge separation efficiency because of the electron injection to graphene from TiO2 conduction band. Other factor that contribute to self-cleaning activity is the electrical conductivity of the graphene added to TiO2 thin film. The graphene added to TiO2 films have a lot of potential in various indoor application due to its fantastic characteristics such as not expensive, transparent, highly conductive, exhibits superhydrophilic properties, and very much photocatalytically active.

Ag/TiO2 thin film was prepared by the sol-gel method through the hydrolysis of titanium tetraisopropoxide and silver nitrate solution. Spin coating method was used to get uniform film on ITO glass substrate followed by annealing process for 1 hour. After that, all the samples were characterised using GIXRD and FESEM and undergone water contact angle test and MB degradation. Silver ion concentrations were varied to observe the effect on crystalline state, morphology, wettability and photocatalytic properties. The results showed that Ag/TiO2 thin film was in anatase phase and it could degrade nearly 70% of methylene blue after 150 min illumination. The formed Ag/TiO2 thin film has excellent self-cleaning property with compact, continuous, smooth, and good hydrophilicity property.

This research focus on the effect of polyethylene glycol (PEG) on TiO2 thin film. Sol-gel method is the best method which tends to be used due to its simplicity, good chemical homogeinity and high purity of the product. Titanium (IV) isopropoxide, isopropanol and acetic acid are the three different chemical which being used to make sol solution. The samples was then will annealed at three different temperature which are 400 °C, 500 °C and 600 °C to observed the phase composition of TiO2 added PEG thin film and pure TiO2 by using x-ray diffraction (XRD) analysis and the structural surface by using scanning electron microscope (SEM) analysis. The XRD analysis show the anatase phase present for the sample of pure TiO2 thin film and rutile phase present for the sample of TiO2 added PEG thin film. The micrograph of SEM show that with the addition of PEG at high temperature will give the analysis of flaky large cracked which is not separated to each other on the surface coating. Meanwhile, pure TiO2 give the result of irregular shape structure of the film.

There have been experiments on TiO2 thin films synthesized utilizing sol-gel techniques. The sol-gel method is a straightforward technology that gives numerous benefits to the researcher, for instance, material’s reliability, reproducibility, and controllability. Following from there, it can be utilized to make high-quality nano-structured thin films. According to previous studies, the TiO2 films’ characteristics occur to be highly dependent on the production parameters and initial materials utilized. Controlling the formation of TiO2 thin films with the sol-gel method was momentarily discussed here.