Preparation And Photocatalytic Performance Of Nano-TiO₂ Composites

With the deepening of research on titanium dioxide,it has been found that the application prospect of titanium dioxide is very broad,especially in the photocatalytic degradation of environmental organic wastewater,it shows high application value.Nano titanium dioxide has the characteristics of high catalytic activity,non-toxic and environmentally friendly,etc.In the field of photocatalysis,it has unparalleled advantages over other materials.In recent years,researchers have devoted themselves to improving the performance of titanium dioxide photocatalytic materials,reducing costs,and researching supported application technologies.This paper innovatively optimizes the laboratory preparation process of titanium dioxide,from the perspective of economy,relatively cheap and easily available raw materials and relatively simple processes are used to prepare anatase nano-titanium dioxide with good performance.Explore and study methods of improving photocatalytic performance such as doping modification and loading modification,preparation of magnetic ternary composite photocatalytic material,the recycling of the photocatalyst wastewater treatment process is realized.The research uses spectral analysis,electron microscopy analysis,photoelectric performance and magnetic performance testing and other characterization methods to characterize the physical properties of the prepared materials.Standard photocatalytic degradation probe reaction was used to characterize the photocatalytic performance of the prepared samples,research and analyze its mechanism of action.The details are as follows:（1）Anatase nano-TiO₂was successfully prepared by an improved sol-gel hydrothermal method.Through single-factor experiments,it was determined that the amount of water added to the precursor in this method was 3 m L,p H=6,and the hydrothermal temperature was120°C.The hydrothermal time of 18 h is the best process parameter.The preparation method has simple raw materials without adding template or surfactant,mild conditions and no need for high-temperature roasting phase change process,and the prepared sample particles are fine and uniform,and the photocatalytic activity is compared with the market P25 The photocatalyst has been significantly improved;（2）In terms of improving the performance of TiO₂,there are mainly two methods of doping and loading.Based on the improved sol-gel hydrothermal method,using urea as the nitrogen source,the introduction of N-doped modified nano-TiO₂,The results show that the N-doped TiO₂photocatalyst has increased crystallinity,expanded light response range,and enhanced photocatalytic performance;using SSZ-13 zeolite as a carrier,the nano-TiO₂was loaded and studied,and the loaded material had an effect on organic pollutants in wastewater.It has the effect of adsorption and enrichment,and the photocatalytic degradation effect is better;（3）Using the concept of easy recovery of magnetic particles in a magnetic field environment,the composite photocatalyst material of magnetic SSZ-13 zeolite loaded with TiO₂was prepared by the ultrasonic-assisted hydrothermal method.The addition of magnetic nano Fe₃O₄will not damage the original structure of the zeolite.In addition to degradation experiments,recycling experiments were also designed.The results of the experiments showed that the synergistic effect between the surface material components can improve the photocatalytic performance while also efficiently recycling,the average recovery rate is 90%,and the removal rate of 4 cycles of degradation experiments can still reach 79.6%.