Synthesis Of Copper-doped BiVO₄ Composite Photocatalyst And Its Visible-Light Photocatalysis Degradation Research On The Indoor Formaldehyde

In the indoor environmental pollution,formaldehyde is one of the most typical volatile organic compounds,which is also identified as carcinogenic and teratogenic substances by the World Health Organization.And with the deep application of photocatalytic technology in environmental governance,the photocatalytic treatment to indoor air pollutants has been developed gradually as well.While with the mature development of Ti O2 photocatalyst,its disadvantages are gradually emerging,such as the gap width is large,photo-generated electrons and holes easily combine and other issues.Therefore,it is urgent to find a new type of photocatalytic materials which can respond under visible light and have good photocatalytic activity.Among them,bismuth-based photocatalyst is a kind of new type of catalyst,which given much attention,especially the bismuth vanadate catalyst.Because it is in response to visible area,it has potential research value and application prospect in the degradation of organic pollutants.In this paper,Cu-doped Bi VO4 photocatalytic materials were prepared by hydrothermal method,and the optimum preparation parameters were determined by orthogonal test firstly.Then the glass culture vessel loaded Cu-Bi VO4 catalytic materials were prepared according to the optimum process parameters,and its crystal structure,crystal phase and crystal morphology were analyzed.Meanwhile the photocatalytic activity of Cu-Bi VO4 catalytic material was studied by using PPM htv formaldehyde detector in the homemade small environment simulating chamber,which was used to simulate the indoor environment.Then the effects of initial concentration of formaldehyde,light intensity and catalyst dosage on the photocatalytic degradation of formaldehyde were also investigated thirdly.At last,the newly coated coating is used as a dynamic source of contamination,to simulate the indoor environment which decoration is synchronized with work,and the purification effect of the photocatalytic materials was investigated.The study concluded that:(1)The optimum technological parameters of Cu-Bi VO4 catalyst were obtained by orthogonal test.They are,the hydrothermal temperature was 180?,the Cu doping content was 1%,the p H value was 7 and the hydrothermal time was 8 h.Among them,the hydrothermal temperature and the Cu doping amount have a great influence on the catalytic activity of the catalyst.(2)X-ray diffraction(XRD)and scanning electron microscopy(SEM)show that Cu-Bi VO4 powder is the best monoclinic system with better photocatalytic performance and higher crystallinity.And its particle size is small,about 26.26 nm.What's more,it is a quadrilateral granular,dispersed evenly,and the particles are evenly distributed on the surface with amorphous granules.(3)Cu-Bi VO4 catalyst has good photocatalytic activity in the degradation of formaldehyde.In a certain range,the photocatalytic activity increases with the increase of initial concentration and light intensity,and the photocatalytic activity increases slightly with the increase of the amount of catalyst.(4)In the course of dynamic experiments,the concentration of formaldehyde released from the coating increases with time.While under the photocatalytic action of Cu-Bi VO4 catalytic materials,the sustained release of formaldehyde on the coating has a better degradation effect.And with the extension of time,the photocatalytic effect is increasing.