Photocatalytic material for efficiently removing high-concentration nitrate through photocatalysis as well as preparation method and application of photocatalytic material

Abstract

The invention discloses a photocatalytic material for efficiently removing high-concentration nitrate through photocatalysis as well as a preparation method and application of the photocatalytic material. The preparation method comprises the following steps: step 1, preparing citrate stabilized silver nanoparticles; step 2, synthesizing and functionally modifying SiO2; step 3, preparing Ag / SiO2; and step 4, preparing an Ag / SiO2@cTiO2 core-shell structure. The photocatalytic material prepared by the method is high in reduction catalytic activity, high-concentration nitrate can be quickly removed, and relatively high nitrogen selectivity is achieved. Meanwhile, due to the protection of a titanium dioxide shell, the material has relatively high stability, and high-concentration nitrate in water can be removed under the condition that high-concentration chloride ions coexist.

Description

technical field [0001] The invention belongs to the field of environmental functional materials, and relates to a photocatalytic material, in particular to a photocatalytic material for highly efficient photocatalytic removal of high-concentration nitrate, a preparation method and application thereof. Background technique [0002] Due to the burning of more and more fossil fuels, the continuous increase in the demand for nitrogenous raw materials in industry and agriculture, and the general inefficiency of use, a large amount of nitrate from human activities has been lost into water bodies and has become one of the most abundant pollutants in surface and groundwater. One, causing a series of environmental and human health problems. Countries and organizations all over the world have set strict upper limits on the concentration of nitrate in drinking water. As a relatively new environment-friendly technology, photocatalytic denitrification has become a research hotspot for t...

AI Technical Summary

Problems solved by technology

The preparation process of this material needs to go through a preparation process of more than 96 hours, and the preparation process is extremely cumbersome. Although it has a good removal effect on nitrate, it has not evaluated the nitrogen selectivity and the stability of the material recycling, which is difficult to be practical. application

[0004] The invention application with the patent application number 201610891842 discloses a method for removing nitrate nitrogen from water by photocatalytic reduction. The invention discloses an Ag-Ag 2 O / TiO 2 The composite photocatalyst can perform photocatalytic denitrification and denitrification when formic acid is used as a sacrificial agent. However, the catalytic effect of this catalyst in the face of high concentration of nitrate has not been evaluated, and Ag It is easy to react with Cl- to form silver chloride and be inactivated

[0005] The invention application with the patent application number 201910126461.6 discloses a nitride-based catalyst for highly efficient photocatalytic reduction of nitrate in water and a water treatment method thereof. The invention discloses a kind of chemical formula X x N y Covalent nitrogen compounds, although it has a high removal rate for nitrate, but its nitrogen selectivity is low, only less than 50%, which greatly limits its application

[0006] In summary, the current single titanium dioxide-based photocatalysts have problems such as low reduction and removal of nitrate nitrogen and poor selectivity, while modified pertitanium dioxide generally has problems such as low reduction efficiency of high-concentration nitrate and poor stability in complex systems.

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