Magnetically-separable multiplex photo-catalyst, and preparation method and application thereof

Abstract

The invention discloses a magnetically-separable multiplex photo-catalyst, and a preparation method and an application thereof. The preparation method is characterized in that the preparation method comprises the steps that Fe3O4 columns enter interlayers, hole channels and the surface of natural sepiolite soil in a supporting manner with a chemical method to ensure that the natural sepiolite soil achieves negative magnetism; butyl titanate is dissolved in absolute ethyl alcohol; anhydrous acetic acid is dropwise added and serves as a hydrolytic inhibitor; then magnetic sepiolite is added and stirred, and reacts to form a liquid A; distilled water is added to absolute ethyl alcohol to form a solution; a pH value of the solution is adjusted to 2-3 with nitric acid at a ratio of 1:1; a liquid B is obtained, then dropwise added to the liquid A slowly, and stirred quickly, reacts for 30-60min, and is subjected to standing and aging for 12-24h to form gel; the gel is washed, subjected to magnetic separation, dried, calcined and ground, and passes through an 80-mesh sieve; and the multiplex photo-catalyst is obtained. The multiplex photo-catalyst is good in adsorbability and photocatalytic activity, wide in response range of an optical wavelength, and magnetically-separable, and can be applied to treatment of heavy metal Cr(VI) and organic 2,4-DCP (2,4-Dichlorophenol) coexisting degradation-resistant waste water.

Description

technical field [0001] The invention belongs to the technical field of chemical engineering and environmental protection engineering, and in particular relates to a magnetically separable composite photocatalyst and its preparation method and application. Background technique [0002] The key to photocatalytic technology is the photocatalytic material, TiO 2 It has become the most commonly used photocatalyst because of its low price, non-toxicity, long service life, high catalytic activity, good thermal stability and corrosion resistance. However, the recombination of photogenerated electrons and holes occurs in nanoseconds, which greatly reduces the catalytic efficiency of photocatalysts. The recombination probability and the increase of the specific surface area enhance the ability of the catalyst to adsorb pollutants, which can greatly improve the efficiency of photocatalytic degradation of pollutants. But powder nano TiO 2 Photocatalysts are easy to agglomerate due to...

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Problems solved by technology

[0003] About Nano-TiO in Suspension System 2 For the separation and recovery of photocatalysts, there are many reports at home and abroad that use glass, metal, adsorbent, natural minerals, ceramics, cation exchange columns, polymers, etc. as carriers to prepare supported nano-TiO 2 photocatalyst; it has also been reported that TiO 2 Direct load to Fe 3 o 4 on, or directly coat Fe on materials such as activated carbon and attapulgite 3 o 4 TiO 2 , by setting an external magnetic field to achieve rapid and effective separation and recovery of photocatalysts, but due to Fe 3 o 4 More lively, poor thermal stability, and TiO 2 The binding ability is also weak, making TiO 2 The loading capacity and photocatalytic activity of the

To avoid TiO 2 with Fe 3 o 4 Direct contact defects have also been reported with SiO 2 As the intermediate layer to prepare magnetic nanocomposite photocatalysts with core-shell structure, but SiO 2 The layer is easy to dissolve and fall off in an aqueous solution at about 90°C, so SiO 2 The stable existence of the middle layer is an open problem

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