Degradation Activity Of BiOX Composite To Aldehydes Pollutants And Its Application

The environmental pollution caused by aldehyde gases released from interior decoration has seriously threatened human health.The environmental photocatalysis has the advantages of green energy saving and no secondary pollution,which is of great significance in solving the application of indoor environmental pollution.In this paper,the purifying agents of bismuth oxychloride/porous titanium hydroxyapatite?BiOCl/P-TiHA?,3D bismuth oxychloride/bismuth oxybromide/graphene oxide heterojunction?3D-BiOCl0.5Br0.5/GO?and bismuth chloride oxychloride/porous titanium hydroxyapatite/sepiolite?BiOCl/P-TiHA/Sep?was prepared with good adsorption and catalytic properties.The adsorption and purification effects of purifying agents on gaseous pollutants such as acetaldehyde and formaldehyde and their purification mechanism were studied.On this basis,BiOCl/P-TiHA/Sep was made into a liquid spray or the composite materials were added to the waterborne paint to study the purification of aldehyde gases by sprays and coatings.The main research contents and conclusions of the paper are as follows:?1?Spherical BiOCl/P-TiHA photocatalyst with high specific surface area were synthesized by Coprecipitation method with porous CaCO₃ as template.The structures and optical absorption properties were characterized by XRD,SEM,EDS,FTIR and UV-Vis.The efficiency and reaction mechanism of BiOCl/P-TiHA for the degradation of acetaldehyde were investigated.The structure of synthesized BiOCl/P-TiHA is consistent with what of the target product.When the molar ratio of BiOCl and TiHA is 5:1,the irradiation time is 120min,the catalytic efficiency of BiOCl/P-TiHA to acetaldehyde can reach 89.6%.And the degradation matched first-order dynamical reaction equation.As a new type of photocatalyst,the BiOCl/P-TiHA has good adsorption and photocatalytic performance,which has application potential in the purification of aldehyde environmental pollutants.?2?A novel 3D bismuth oxychloride/bismuth oxybromide/graphene oxide heterojunction(3D-BiOCl_0.5Br_0.5/GO)with excellent visible light activity were synthesized by doping GO in an as-prepared 3D-BiOCl_0.5Br_0.5 with a facile hydrothermal method.The synthesized 3D-BiOCl_0.5Br_0.5/GO heterojunction exhibited a hierarchical globose corolla-like nanoscale structure with large surface area and appropriate pore size.Introducing appropriate amount of GO sheets into3D-BiOCl_0.5Br_0.5 can improve the surface chemical structure of the 3D-BiOCl_0.5Br_0.5,increase the surface active sites,accelerate electrons transmission,avoid the e^-and h⁺recombination and enhance the oxidation of photogenerated charge.Thereby,the adsorption and degradation capacities of 3D-BiOCl_0.5Br_0.5/GO to acetaldehyde enhanced significantly.Under visible light irradiation,the synthesized samples demonstrated an advanced photocatalytic capacities to the acetaldehyde degradation when compared to pure 3D-BiOCl_0.5Br_0.5.The efficiency of 3D-BiOCl_0.5Br_0.5/GO heterojunction to the acetaldehyde degradation can achieve over 90.2%within 120min at room temperature,indicating the synergistic enhancement between GO and3D-BiOCl_0.5Br_0.5.The enhanced photocatalytic activity mechanism of3D-BiOCl_0.5Br_0.5/GO heterojunction were proposed based on the experimental findings.?3?A bismuth oxychloride/porous titanium hydroxyapatite/sepiolite?BiOCl/P-TiHA/Sep?with good adsorption and photocatalytic activity was prepared by a simple water bath method,and dispersed in an aqueous solution to prepare a liquid dispersion for purifying the environment.The stability of BiOCl/P-TiHA/Sep purifying agent in aqueous solution was studied,and a suitable prescription for environment purifying liquid spray was found.The environmentally-purified liquid spray was repeatedly and uniformly sprayed on the self-made gas purification reaction device,and the purification effect on formaldehyde and hydrogen sulfide gas were measured under the fluorescent lamp.The results showed that the photodegradation rate of environmentally-purified liquid spray for formaldehyde reached 70%at 24h,and for H₂S reached 100%at 120min.?4?The BiOCl/P-TiHA,3D-BiOCl_0.5Br_0.5/GO and BiOCl/P-TiHA/Sep purifiers were added to the coating to prepare an adsorption-photocatalytic wall coating and the adsorption and purification effects of formaldehyde gas were measured in a self-made gas purification reaction device.The results show that the coating has a high degradation rate to acetaldehyde gas when the addition amount of purifying agents is 7.5%,indicating BiOCl/P-TiHA,BiOCl/P-TiHA/Sep,3D-BiOCl_0.5Br_0.5/GO can give the coating a better purification effect.The study provides a new environment for gas pollutants such as indoor aldehydes.