Study On Preparation And Properties Of Bismuth Iodide And Its Composites

With the rapid economic development,we are facing many problems such as lack of fresh water resources,bacterial and viral infections.As one of the methods to solve the energy crisis and environmental biological problems,semiconductor photocatalysis technology has attracted the attention of researchers all over the world.As a new type of photocatalytic semiconductor material,bismuth iodide(BiOI)has attracted a lot of attention due to its high chemical stability,unique crystal structure and many other excellent properties.However,its low photooxidation ability and weak separation rate of photogenerated electrons limit its wide application in practice.Therefore,The project will focus on solving these defects of BiOI.By recycling corn stalks,green synthetic biomass carbon quantum dots(CQDs),using the unique photoluminescence properties of carbon quantum dots and good light-induced charge transfer properties to construct BiOI Binary and ternary multifunctional composite materials.The prepared composite materials were analyzed by a variety of characterization methods,and the main conclusions of the paper were as follows:(1)BiOI prepared by hydrothermal method and deposition method,with an average particle size of 6.84?m.The composition structure,functional groups,morphology and size of the materials were analyzed by various characterization methods,and it was proved that BiOI binary and ternary multifunctional composites were successfully constructed.The doping of CQDs modifies BiOI and the CQDs/BiOI binary composites has higher electron-hole pair separation efficiency than pure BiOI.(2)The organic wastewater simulated by methyl orange(MO)azo dye solution was degraded by CQDs/BiOI/polyurethane sponge ternary composite.The kinetic results show that the degradation of MO by the prepared materials accords with the quasi-first-order reaction kinetics.The 3%CQDs/BiOI/sponge prepared by deposition method has better photocatalytic performance,and the construction of ternary composites is beneficial to the recycling of BiOI powder.The results of active species capture experiments show that the main active substances for photocatalytic degradation of methyl orange are h⁺,·O₂^-and e^-,in which h⁺and e^-play a key role.(3)The CQDs/BiOI binary composite material was used as the antibacterial agent,and Escherichia(E.coli)and Bacillus subtilis(B.subtilis)were used as the target strains to test the antibacterial properties of the prepared materials.The results of plate colony showed that BiOI had poor bacteriostatic effect,3%CQDs/BiOI had the best bacteriostatic effect,and the bacteriostatic effect of E.coli was more obvious than that of B.subtilis.The results of growth curve showed that the concentration of complete inhibition of Escherichia coli and Bacillus subtilis was 0.24 mg/m L and 0.28 mg/m L respectively.h⁺is the main active species of photocatalytic inhibition.