Pvd coating machine TiO2 thin film photoconductivity and photocatalysis, using sol-gel method to spin on quartz substrate to prepare different series of TiO2 thin film samples (F-doped concentration, holding time, film thickness, crystal form), and X-ray diffraction etc. Analysis and testing methods are used to characterize the structure and other properties of the sample. The photocatalytic properties of the samples were characterized by the experimental determination of the photodegradation of methylene blue solution of the thin film samples, and their photoconductivity values were determined. The results showed that the samples with larger photoconductivity values also had better photocatalytic performance, which indicated that there was an inherent relationship between photoconductivity and photocatalytic performance, and provided an experimental basis for the characterization of photocatalysis by physical methods. After analysis, it is concluded that the photocatalytic activity and photoconductivity both have the optimal F-doping concentration ( 2%) and the optimal film thickness ( 331. 5 nm). Anatase-rutile mixed crystals are superior to a single anatase phase.

       Since 1972, when Fujishima discovered the phenomenon of photolysis of water on TiO2 semiconductor single crystal electrodes, people began to study the photocatalysis of heterogeneous semiconductors. Photocatalytic degradation is a complex photochemical reaction, and there are many factors affecting the degradation characteristics, such as light wavelength, light intensity, temperature, pH, etc., and the experiments are also cumbersome. So far, there is no unified and widely applicable standard for the evaluation of photocatalytic activity of TiO2.

       In recent years, researchers have begun to try various physical methods such as surface photovoltage, light-dark conductance ratio, light-state and dark-state conductivities to study and characterize photocatalytic performance, hoping to obtain a simpler method for evaluating photocatalytic performance. TiO2 is a high-resistance semiconductor with very low dark conductivity. Dark resistance is often obtained by measuring micro-current. The measurement of micro-current is easily affected by the measurement accuracy of the instrument and external noise, which reduces the reliability of the measurement results; The conductivity ratio method is affected by the measurement error of dark conductivity.
       At present, the preparation methods of TiO2 thin films include sol-gel method, atomic layer deposition method, vapor deposition method, sputtering method and low temperature plasma jet method, etc. Among them, the sol-gel method has been widely used due to its simple process and low cost. . In this paper, the photoconductivity method was used to characterize the photocatalysis, and the TiO2 films under different conditions were prepared on the quartz substrate by the sol-gel method. Methylene blue was used as the degradation object to study the photocatalytic properties of the films and measure their photoconductivity; in order to accurately compare The photocatalytic performance of each sample was determined. During the experiment, the conditions such as light intensity and temperature were kept as consistent as possible, in order to minimize the external influence of photodegradation. The TiO2 film samples used for photocatalysis research in this experiment are mainly different in doping concentration, holding time, film thickness and crystal form. The effects of various changing conditions on photocatalysis and photoconductivity were analyzed from the characterization tests of different samples to gain a more comprehensive understanding of the relationship between photocatalysis and photoconductivity.
        The introduction of TiO2 thin film photoconductivity and photocatalysis in pvd coating machine is more theoretical. People who do not study this aspect may find it difficult and difficult to understand, but it doesn't matter. Get better.