Preparation Of Full - Band Photocatalytic Composites By Supercritical Alcohol Thermal Technology And Their Properties

Photocatalysis has caused great interest in using solar energy to solve environmental pollution problems. As a typical semiconductor, titanium dioxide has attracted lasting concern due to its low toxicity, low cost, excellent chemical stability and high activity. However, as a result of its wide band gap, UV light excitation and low quantum efficiency（QE）, the practical application of TiO₂ has been prohibited, including pollutants purification, antibacterial and so on. For these reasons, the following three routes were proposed: 1) modifying TiO₂ with carbon through novel technique to extend its light absorption edge to visible region. 2)Expanding the applications of photocatalytic materials to purify highly pathogenic bacteria hospital environment, to replace the traditional antibacterial drugs. 3)Designing efficient catalytic reactor to kill bacteria, meeting the needs of practical application. For the above reasons, this graduation thesis mainly includes the following three parts.（1） Supercritical slovothermal route for Ag/TiO₂-N with enhanced photocatalytic capability in degrading pollutants.In this section, we prepared Ag/TiO₂-N via supercritical solvothermal approach using silver nitrate and tetrabutyl titanate as copper, and titanium source. XRD, SEM and XPS characterizations results showed that supercritical slovothermal treatment resulted in the mesoporous structure, small crystal size, large special surface areas,high crystallinity and high visible-light absorption. Thus, these functional catalysts exhibited high photocatalytic performance and excellent recyclability for MO degradation under visible-light irradiations（λ > 420 nm）.（2） Research of Ag/TiO₂-N photocatalytic antibacterial property of Acimeshobacter baumanniiAg/TiO₂-N prepared by the above method used in photocatalytic antibacterial under visible light. In virtue of SEM, ICP and TOC characterizations to study antibacterial process, The phenomenon of bacterial autolysis and self-healing was investigated, The photocatalytic materials showed excellent activity in the process of destroying acimeshobacter baumannii, effectively avoiding the defects of bacteria resistant by antibiotics.（3） Photocatalytic performance of Bi OI-RGO under long-wave region of visible light and IRAlthough Ag/TiO₂-N has good degradation activity for MO and excellent antibacterial activity to acimeshobacter baumannii in the visible light, the activity in450-780 nm, visible light and infrared light was poor. Bi OI-RGO presented the better property. The physical and chemical properties of the catalysts were characterized by mean of XRD, SEM and XPS. Catalysts exhibited high photocatalytic performance and excellent recyclability for MO degradation under long-wave band of visible light（450-780nm）.