Graphene quantum dots-bismuth tungstate composite photocatalyst and preparation method thereof

Abstract

The invention discloses a graphene quantum dots-bismuth tungstate composite photocatalyst and a preparation method thereof. According to the composite photocatalyst, bismuth tungstate is used as a photocatalyst, and graphene quantum dots are loaded on bismuth tungstate. The preparation method comprises the following steps: carrying out ultrasonic mixing on a graphene quantum dots solution, sodiumtungstate and deionized water, and then adding cetyl trimethyl ammonium bromide to obtain a solution A; dissolving bismuth nitrate in acetic acid to prepare a solution B, slowly adding the solution Binto the solution A and stirring to obtain a precursor suspension; transferring the precursor suspension into a microwave reaction instrument to carry out a microwave reaction, centrifuging the suspension and drying to prepare a graphene quantum dots-modified bismuth tungstate composite photocatalyst. The composite photocatalyst has good degree of crystallization, uniform morphology, has high photocatalytic activity, strong light absorption capability and high light-generated electron-cavity separation efficiency, and is safe and stable. The technology is simple, reaction conditions are mild and easy to control. The graphene quantum dots-bismuth tungstate composite photocatalyst is easy for industrial production and has good industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of photocatalytic degradation of organic wastewater, in particular to a graphene quantum dot-bismuth tungstate composite photocatalyst and a preparation method thereof. Background technique [0002] The development of high-efficiency and low-consumption organic sewage treatment technology is of great significance to alleviate the increasingly serious water pollution problem and solve the problem of drinking water safety for residents. Traditional physical, chemical and biological degradation water treatment technologies are not ideal for refractory organic wastewater treatment and have the disadvantages of secondary pollution and long reaction time. In 1976, Carey et al. used TiO for the first time 2 The degradation of polychlorinated biphenyls by photocatalytic technology has opened the prelude to the research of photocatalytic technology in the field of environmental governance. Photocatalytic wastewater...

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Problems solved by technology

Cao Ranran et al. (Materials Characterization 101(2015) 166–172) prepared different yttrium-doped Bi by hydrothermal method 2 WO 6 Photocatalyst (Y-Bi 2 WO 6 ), the results show that: when the yttrium doping amount is 1%, 1%Y-Bi 2 WO 6 The catalytic degradation rate of rhodamine B is the best (up to about 88% in 4h), but the corresponding fluorescence spectrum intensity (PL) increases when the doping amount of yttrium continues to increase, indicating that the excessive formation of defects leads to the electron-hole recombination rate increase, the final photocatalyst degradation activity decreased (the 4h degradation rate was only 78% when the doping amount was 3%)

[0004] At the same time, the traditional hydrothermal preparation technology of photocatalysts will face problems such as long preparation period of photocatalysts and uneven heating of the reaction solution system in the actual industrial application process.

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