Modified nanometer titanium dioxide photocatalyst, and preparation method and application thereof

Abstract

The invention provides a modified nanometer titanium dioxide photocatalyst and a preparation method and application thereof. The preparation method comprises the following steps: 1) adding nanometer TiO2 powder in a reactor filled with CCl4, adding a CCl4 solution of PCl3 at 80 DEG C, carrying out a reaction at 90 DEG C for 2 to 4 h and removing CCl4 to obtain powder I; 2) preparing 4-sodium sulfonate-phenylalkyl sodium sulfonate; 3) preparing 4-sodium sulfonate-phenyl-brominated alkyl sodium sulfonate; and 4) pouring treated metallic magnesium into a reactor filled with anhydrous ether, adding the product obtained in the step 3 until magnesium is fully reacted, adding bis(1,3-dibenzylphosphine)propyl nickel dichloride and the product obtained in the step 1), carrying out reflux for 15 to 20 h and carrying out treatment so as to obtain a finished product. The modified nanometer titanium dioxide photocatalyst is separated and recovered after degradation of high-concentration benzene-series pollutants, and the photocatalyst still has high catalytic activity after usage a plurality of times; after the photocatalyst is used 7 times, the degradation efficiency of the photocatalyst to high-concentration and hardly degradable benzene series reaches 100% in 8.0 h.

Description

technical field [0001] The invention belongs to the technical field of catalytic oxidant and its preparation, in particular to a modified nano-titanium dioxide photocatalyst and its preparation method and application. Background technique [0002] The high-concentration wastewater in the modern chemical industry has the following characteristics: high chroma, peculiar smell, easy to emit pungent stench, polluting the environment; organic matter is supersaturated, the concentration (in terms of COD) is higher than 2000mg / L, and some are even as high as dozens 10,000 mg / L, and contains different types of surfactants and organic solvents, etc., with strong self-emulsification, self-dispersion and collection capabilities, and pollutants are in suspension and droplets; the composition is complex, mainly aromatic compounds and heterocyclic compounds Mostly (BOD 5 / COD value <0.3), also contains sulfides, nitrides, heavy metals and other toxic organic substances, the biodegrada...

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Problems solved by technology

Through the superior adsorption capacity of mesoporous materials, the catalyst enhances the visible light catalytic degradation performance of high-concentration organic pollutants, and has the advantages of simple operation, low cost, easy availability of raw materials and high UV-visible light activity, but there is a loading force Weaker, TiO cannot be avoided during long-term cycling 2 The problem of the loss of nanoparticles, and the degradation experiment of pollutants proves that the wastewater treatment concentration is low and the adsorption capacity is limited, which is far from the photocatalytic characteristics and mechanism process of the actual high-concentration wastewater; Chinese patent CN102527439 announced a Photocatalytically active polymer / TiO 2 The preparation method of the hybrid film realizes the TiO 2 The chemical loading of nanoparticles in the polymer film not only effectively improves the agglomeration of nanoparticles, but also after the photocatalysis is over, the hybrid film can be directly taken out from the organic pollutant solution, and the nanoparticles are recovered, which solves the problem of traditional The load method is difficult to resolve during long-term use of TiO 2 The loss of nanoparticles ensures high photocatalytic activity in long-term use, and the process is simple, but similar to traditional hydrophobic modifiers, the hybrid film itself is easily exposed to TiO under light. 2 Degradation greatly reduces the stability, and the basement membrane fiber diameter of the hybrid membrane increases from 2-50nm of the primary particle size to 100-300nm, which limits the improvement of photocatalytic activity

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