Preparation Of N-Si Codoped TiO₂Photocatalysts And Its Photocatalytic Properyty

With the development of industry, wastewater pollution brings many potentialproblems to human beings and the environment. Photocatalytic oxidation technologyis a sustainable development technology in environment. Titanium dioxide is the mostpromising photocatalyst in photocatalytic oxidation. However, the low utilizationefficiency of solar energy is an important reason limiting the industrial application ofthe titanium dioxide catalyst. Doping TiO2to improve the utilization efficiency ofsolar energy is a hotspot in visible light photocatalysis research. Compared withsingle-doping, co-doping is more effective.In this work, we prepared N-Si codoped TiO2(NST) by a simple method by SiCl4,TiCl4and ammonia water co-hydrolysis. Photocatalytic activity of NST was evaluatedby phenol to discuss the degradation mechanism. Degradation effect used Si dopedphotocatalysts was better than undoping photocatalysts (NT). The calcinationtemperature, doped ratio, H2O2modification condition, pH and different lightresources were discussed. For the photodegradation of phenol, the optimal molar ratioof Si/Ti and the calcination temperature was1:4and650°C, respectively. The phenolremoved91%in6h under solar light. Two kinds of light sources applied for thephenol degradation to determine the most suitable light for photocatalysts. The resultsshowed the photocatalysts have a good usability of solar light. The reusability of NSTwas relatively good in this study and it could remove82.7%after the third running.Structure characteristics analysis of as-prepared samples were studied by X-raydiffractometer (XRD), Diffuse reflectance UV-visible absorption spectra (UV-visDRS), X-ray photoelectron spectra (XPS) and Transmission electronmicroscopy(TEM). The results showed that the N-Si codoped TiO2is in crystal state.The co-doping process did not change the TiO2crystal, but the Si-doped inhibited thetransformation from anatase to rutile phase. XPS and EDX characterization results showed that nitrogen and silicon doped into the catalyst successfully. Band gapreducing showed that the enhancement of the ability to use the sunlight. NST withgood prospects of development had excellent photocatalytic property and had a goodusability of solar light.