CQDs/Bi7O9I3 composite photocatalyst with visible-light antibacterial property as well as preparation method and application thereof

Abstract

The invention discloses a CQDs / Bi7O9I3 composite photocatalyst with a visible light antibacterial property as well as a preparation method and application of the CQDs / Bi7O9I3 composite photocatalyst. The method includes adding citric acid and ethylenediamine into water, carrying out hydrothermal reaction, and dialyzing to obtain a CQDs solution; adding Bi(NO3)<3>.5H2O into ethylene glycol, adding KI, stirring and centrifuging to obtain a Bi7O9I3 catalyst; adding the Bi7O9I3 catalyst into water, adding the CQDs solution, carrying out hydrothermal reaction, and filtering to obtain the composite photocatalyst. According to the CQDs / Bi7O9I3 composite photocatalyst with the visible light antibacterial property, the preparation method is simple, the reaction condition is mild, and the cost is low; thin flaky Bi7O9I3 catalyst can be prepared by the method, the specific surface area is increased, the contact area between bacteria and the catalyst is increased, and the photocatalytic antibacterial efficiency can be improved.

Description

technical field [0001] The invention relates to the field of photocatalytic antibacterial materials, in particular to a CQDs / Bi with visible light antibacterial properties 7 o 9 I 3 Composite photocatalyst and its preparation method and application. Background technique [0002] With the continuous advancement of urbanization, environmental problems such as water pollution are becoming more and more serious. A large number of pathogenic microorganisms that grow wantonly in water pose a huge threat to human health. There is an urgent need to develop efficient disinfection technology to kill the pathogenic microorganisms that breed therein. Semiconductor photocatalytic disinfection technology has aroused great interest. It relies on natural, abundant and sustainable solar energy. Active species such as photogenerated electron holes generated by semiconductors under solar irradiation cause oxidative damage to bacterial cell structures and inactivate pathogenic microorgani...

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Problems solved by technology

[0003] Traditional photocatalytic materials such as TiO 2 , ZnO and other wide-bandgap semiconductors are considered to be effective photocatalytic antibacterial agents because of their high redox ability of photogenerated carriers, but they only respond to ultraviolet light in sunlight, and ultraviolet light only accounts for the solar energy. 4% of light, resulting in inefficient use of sunlight

Although traditional BiOI has a good absorption of visible light, its photogenerated carrier recombination rate is high. Although CQDs with good electrical conductivity and electron capture ability are combined with it, it can effectively inhibit the recombination of photogenerated electron-hole pairs and improve the efficiency of photogenerated electrons. The separation efficiency of electron-hole pairs, however, BiOI provides more active sites because of its relatively small specific surface area. At the same time, the band gap is too narrow, and the redox ability of photogenerated carriers is weak, which is not conducive to the actual water pollution and disinfection.

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