Preparation method for sol-gel one-step low-temperature synthesis of pure-phase Bi25F3O40/ZnO photocatalyst

Abstract

The invention discloses a preparation method for sol-gel one-step low-temperature synthesis of a pure-phase Bi25F3O40 / ZnO photocatalyst. The photocatalyst is applied to degradation reaction of low-concentration phenol aqueous solution under simulated sunlight. The photocatalyst is prepared according to a sol-gel method by steps: taking glycine as a complexing agent for complexing reaction of Fe(NO3)3.9H2O, Bi(NO3)3.5H2O and Zn(NO3)2.6H2O, calcining at 500 DEG C for 3h under the air atmosphere to form a semiconductor catalyst, wherein a ratio of amount of substance of Fe to Bi to Zn is 1:1:4, and a mole ratio of glycine serving as the complexing agent to total metal ions is 1:2. The pure-phase Bi25F3O40 / ZnO photocatalyst is synthesized at a low temperature by sol-gel one-step preparation with glycine serving as the complexing agent. The preparation method is convenient and simple in operation and low in cost and is high in catalytic activity and structural stability in application to degradation of the low-concentration phenol aqueous solution.

Description

technical field [0001] The invention relates to a sol-gel one-step low-temperature synthesis of pure phase Bi 25 FeO 40 The invention relates to a preparation method of ZnO photocatalyst, which belongs to the technical field of preparation technology of inorganic non-metallic materials and semiconductor photocatalytic materials, and applies it to the degradation of low-concentration organic pollutants—phenol under simulated sunlight. Background technique [0002] In the production of most coal chemical products, such as coal gasification, liquefaction, coking and tar processing, a large amount of phenol-containing wastewater will be produced. Due to the high toxicity and strong Irritant, it is listed as one of the priority pollutants, but phenol itself is very difficult to degrade. For the treatment of phenol and phenolic wastewater, traditional methods including extraction, membrane separation, biological treatment, chemical oxidation or electrochemical catalytic oxidatio...

AI Technical Summary

Problems solved by technology

[0002] In the production of most coal chemical products, such as coal gasification, liquefaction, coking and tar processing, a large amount of phenol-containing wastewater will be produced. Due to the high toxicity and strong Irritant, listed as one of the priority pollutants, but phenol itself is very difficult to degrade

For the treatment of phenol and phenolic wastewater, traditional methods including extraction, membrane separation, biological treatment, chemical oxidation or electrochemical catalytic oxidation have more or less disadvantages: high energy consumption, incomplete degradation, low mineralization, Or there is a high possibility of causing secondary pollution

[0003] The photocatalytic oxidation reaction uses semiconductors as catalysts. Traditional semiconductor photocatalysts include ZnS, TiO 2 , ZnO, CdS, SnO 2 and Fe 3 o 4 etc., but ZnS, ZnO, SnO 2 , CdS and Fe 3 o 4 Such photocorrosion phenomena often occur, seriously reducing the catalytic activity, while TiO 2 Semiconductor photocatalytic oxidation technology has the outstanding advantages of high efficiency, low energy consumption, easy operation, mild reaction conditions, wide application range, and can reduce secondary pollution, etc., while TiO 2 The catalyst itself is non-toxic, cheap, efficient, and stable in performance, so it has become a research hotspot for scientific researchers.

But TiO 2 It can only absorb ultraviolet light (less than 4%) with a wavelength of less than 387nm, and has no photocatalytic activity under visible light irradiation, while artificial ultraviolet light sources have defects such as high power consumption, expensive equipment, and poor stability. 2 At the same time of photocatalyst modification, developing a new photocatalyst that can absorb most of the visible light in sunlight, using oxygen in the air as an oxidant, and effectively degrading toxic pollutants has become a key scientific problem in the field of photocatalysis.

[0004] In the existing research, there is no research about Bi 25 FeO 40 / ZnO photocatalyst reported, while for Bi 25 FeO 40 Most of them are synthesized by hydrothermal method, the hydrothermal method takes a long time, the reproducibility of sample preparation is poor, and it is difficult to obtain a pure catalyst product due to the influence of hydrothermal conditions

At present, using glycine as a complexing agent, the pure phase Bi 25 FeO 40 / ZnO photocatalyst, this method is simple to operate, easy to scale up, and the preparation of samples has good repeatability, and the research on photocatalytic degradation of phenol has not been reported yet

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