Nitrogen-doped iron nanotube and preparation method and application thereof

Abstract

The invention belongs to the field of environmental functional materials, and provides a preparation method and electrocatalytic application of a nitrogen-doped iron (FeN) nanotube. In the nitrogen-doped iron nanotube, FeN active sites are dispersedly packaged in a tubular NC shell layer. The preparation method comprises the following steps: enabling Fe to grow nitrogen-doped iron nanotubes through autocatalysis, and packaging FeN active sites in a tubular NC shell layer in a dispersed manner. The FeN nanotube has a high specific surface area, a large pore volume, wide pore size distribution,high-density and high-stability FeN active sites and a one-dimensional electron transfer channel; a working electrode prepared from the FeN nanotube shows high denitrification performance in the fieldof environment, the nitrate removal rate can reach 88-96%, and the nitrogen selectivity is 85-91%; and relatively high denitrification activity and nitrogen selectivity are still kept in a wide pH value range and after multiple electrocatalytic cycles.

Description

technical field

[0001] The invention belongs to the field of environmental functional materials, and in particular relates to a nitrogen-doped iron nanotube, its preparation method and electrocatalytic application. Background technique

[0002] Excessive nitrogen and other nutrient-rich oxygen salts in the water body lead to excessive reproduction of algae and other plankton, causing severe eutrophication of surface water bodies such as the Haihe River Basin, resulting in disordered water ecosystems, extinction of biological species, and the formation of large areas of dead water. , water eutrophication has become one of the most severe environmental challenges facing the world. NO 3 - It is the final product of the decomposition of nitrogen-containing organic matter through inorganicization. It is the most stable nitrogen-containing compound in an aerobic environment. It has high fluidity and high solubility, and is a key link in maintaining nitrogen balance in the ecosys...

Examples

Embodiment 1

[0039] 1. The preparation of nitrogen-doped iron nanotubes, the specific steps are as follows:

[0040] (1) put g-C 3 N 4 (0.8mol) and glucose (3.4mol) were placed in water, mixed evenly to form a uniform dispersion system, and ferric chloride (1.2mol) solution was added to the uniform dispersion system, and after ultrasonic reaction for 3 hours, it was transferred to a hydrothermal reaction kettle React at 120°C for 12h, after repeated centrifugation and washing, dry in a vacuum oven at 80°C for 6h.

[0041] (2) After the product obtained in step (1) was pyrolyzed at 800° C. for 2 h in a tube furnace in a nitrogen (80 mL / min) atmosphere, the core-shell FeN nanotube catalytic material could be obtained.

[0042] 2. Apply the obtained core-shell nitrogen-doped iron metal nanomaterials to electrocatalytic denitrification

[0043] The obtained FeN nanotube catalytic material (2 mg): carbon black: polyvinylidene fluoride (PVDF) was coated on a nickel mesh (1.2 cm × 1 cm) accord...

Embodiment 2

[0053] The preparation of nitrogen-doped iron nanotubes and the method for catalytic reduction of nitrate are as in Example 1, except that the doping amount of Fe in the process of preparing the FeN catalyst is 5wt%, and the nitrogen selectivity of the prepared catalyst FeN-5 is 50 %, the removal rate of nitrate is 62%.

Embodiment 3

[0055] The preparation of nitrogen-doped iron nanotubes and the method of catalytic reduction of nitrate are as in Example 1, except that the doping amount of Fe in the process of preparing FeN catalyst is 35wt%, and the nitrogen selectivity of the prepared catalyst FeN-35 is 86 %, the removal rate of nitrate is 91%.

technical field

[0001] The invention belongs to the field of environmental functional materials, and in particular relates to a nitrogen-doped iron nanotube, its preparation method and electrocatalytic application. Background technique

[0002] Excessive nitrogen and other nutrient-rich oxygen salts in the water body lead to excessive reproduction of algae and other plankton, causing severe eutrophication of surface water bodies such as the Haihe River Basin, resulting in disordered water ecosystems, extinction of biological species, and the formation of large areas of dead water. , water eutrophication has become one of the most severe environmental challenges facing the world. NO 3 - It is the final product of the decomposition of nitrogen-containing organic matter through inorganicization. It is the most stable nitrogen-containing compound in an aerobic environment. It has high fluidity and high solubility, and is a key link in maintaining nitrogen balance in the ecosys...

Examples

Embodiment 1

[0039] 1. The preparation of nitrogen-doped iron nanotubes, the specific steps are as follows:

[0040] (1) put g-C 3 N 4 (0.8mol) and glucose (3.4mol) were placed in water, mixed evenly to form a uniform dispersion system, and ferric chloride (1.2mol) solution was added to the uniform dispersion system, and after ultrasonic reaction for 3 hours, it was transferred to a hydrothermal reaction kettle React at 120°C for 12h, after repeated centrifugation and washing, dry in a vacuum oven at 80°C for 6h.

[0041] (2) After the product obtained in step (1) was pyrolyzed at 800° C. for 2 h in a tube furnace in a nitrogen (80 mL / min) atmosphere, the core-shell FeN nanotube catalytic material could be obtained.

[0042] 2. Apply the obtained core-shell nitrogen-doped iron metal nanomaterials to electrocatalytic denitrification

[0043] The obtained FeN nanotube catalytic material (2 mg): carbon black: polyvinylidene fluoride (PVDF) was coated on a nickel mesh (1.2 cm × 1 cm) accord...

Embodiment 2

[0053] The preparation of nitrogen-doped iron nanotubes and the method for catalytic reduction of nitrate are as in Example 1, except that the doping amount of Fe in the process of preparing the FeN catalyst is 5wt%, and the nitrogen selectivity of the prepared catalyst FeN-5 is 50 %, the removal rate of nitrate is 62%.

Embodiment 3

[0055] The preparation of nitrogen-doped iron nanotubes and the method of catalytic reduction of nitrate are as in Example 1, except that the doping amount of Fe in the process of preparing FeN catalyst is 35wt%, and the nitrogen selectivity of the prepared catalyst FeN-35 is 86 %, the removal rate of nitrate is 91%.

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