A preparation method of WP2-P-WO3-P-Fe2O3 heterostructure nanosheet for water treatment

Abstract

The application relates to a preparation method of a WP2-P-WO3-P-Fe2O3 heterostructure nanosheet for water treatment, in particular to the following steps: Fe(NO3)3.9H2O is added into deionized water, a hydrothermal reaction is carried out in an oven, Fe2O3 nanosheets are obtained after centrifugal drying; Na2WO4.2H2O, water and concentrated hydrochloric acid are mixed, a hydrothermal reaction is carried out, WO3 nanosheets are obtained after centrifugal drying; the prepared Fe2O3 nanosheets and the prepared WO3 nanosheets are mixed with ethanol, are dropped and smeared on commercialized nickel-iron foam, are put into a porcelain boat, NaH2PO2.H2O is put into another porcelain boat, and WP2-P-WO3-P-Fe2O3 heterostructure nanosheets are obtained after roasting under an Ar atmosphere; and the WP2-P-WO3-P-Fe2O3 heterostructure nanosheets are applied to water treatment.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of WP2-P-WO3-P-Fe2O3 heterostructure nanosheet for water treatment, and belongs to the field of material preparation and application. BACKGROUND

[0002] Hydrogen energy is widely considered as a renewable energy with broad prospects and can have a transformative impact on human life. Electrocatalytic water splitting includes two half-reactions-electrocatalytic oxygen evolution reaction and electrocatalytic hydrogen evolution reaction, and electrolysis of water is an effective path to produce high-quality hydrogen and oxygen. Due to the slow reaction kinetics, it is urgent to develop efficient catalysts to accelerate the water splitting process. Although platinum and ruthenium oxide-based catalysts exhibit good water reduction and water oxidation activity, their high price limits their large-scale commercial application. It is urgent to develop bifunctional non-noble metal catalysts.

[0003] Recent studies have found that transition metal phosphides have good water oxidation and water reduction activity. Liu's team treated carbon cloth in nitric acid solution at 100 DEG C for 10 h, and then cleaned it in acetone, ethanol and deionized water; WCl6, oxalic acid, ethanol and the like were added and transferred to a reaction kettle, Ar was introduced, 180 DEG C was treated for 10 h, and then 500 DEG C was calcined for 2 h to obtain a carbon cloth loaded WO3 nanosheet array; the array is reacted with NaH2PO2 to obtain WP2 / CC and WP / CC; WP2 / CC and WP / CC catalyze water reduction reaction under acidic conditions, and the voltage is 140 mV and 175 mV respectively when the current density is 10 mA / cm 2 (International Journal of Hydrogen energy 45 (2020) 28576-28585). Lu's team synthesized a carbon cloth loaded Ni-WO3 nanosheet array, reacted it with NaH2PO2 to obtain Ni-WP2 / CC, which showed high acidic water reduction performance, and the current density was 10 mA / cm 2 (Journal of Energy Chemistry 55 (2021) 17-24). Xu's team used hydrochloric acid to adjust the pH of a Na2WO4·2H2O solution to 1.2; then oxalic acid, H2WO4, (NH4)2SO4, and foamed Ni were added; it was hydrothermally treated at 180 DEG C for 10 h to obtain WO x / NF, and then calcined at 450 DEG C for 1 h to obtain a foamed Ni loaded WO3 nanorod; then reacted with NaH2PO2 to obtain WP2 / NF; the material catalyzes water splitting, and the current density is 10 mA / cm 2The time needs a voltage of 1.65V (Applied Surface Science 546 (2021) 148926). The WP2-P-WO3-P-Fe2O3 heterostructure nanosheet is constructed, the electronic coordination state of W is adjusted, and the activity of the water decomposition is changed, which has important research value. SUMMARY

[0004] The application aims to provide a preparation method of a WP2-P-WO3-P-Fe2O3 heterostructure nanosheet for water treatment.

[0005] In order to achieve the above purpose, the technical scheme of the application is as follows:

[0006] (1) Preparation of the WP2-P-WO3-P-Fe2O3 heterostructure nanosheet: ① 0.5-1.2g Fe(NO3)3·9H2O is added to 50-70mL deionized water, and hydrothermal reaction is carried out at 160-200℃ in an oven for 8-20h, and Fe2O3 nanosheet is obtained after centrifugal drying; ② 0.6-0.8g Na2WO4·2H2O, 40-60mL water and 6-8mL concentrated hydrochloric acid are mixed, and hydrothermal reaction is carried out at 160-200℃ for 8-18h, and WO3 nanosheet is obtained after centrifugal drying; ③ 80-120mg Fe2O3 nanosheet prepared in the above ① and 80-120mg WO3 nanosheet prepared in the above ② are mixed with ethanol, and are dropped and spread on 2×3cm 2 of commercialized nickel-iron foam, and 0.8-1.2g NaH2PO2·H2O is put into another porcelain boat, and WP2-P-WO3-P-Fe2O3 heterostructure nanosheet is obtained by calcining at 250-400℃ for 1-2h under Ar atmosphere, and the temperature rising speed is 5℃ / min. The preparation method is as follows: the Fe2O3 nanosheet belongs to standard card JCPDS #33-0664, and the nanosheet diameter is 20-46nm; the WO3 nanosheet belongs to standard card JCPDS #43-1035, and the nanosheet diameter is 80-400nm; and the WP2-P-WO3-P-Fe2O3 heterostructure nanosheet diameter is 52-260nm, and belongs to standard card WO3 JCPDS #43-1035, Fe2O3 JCPDS #33-0664 and WP2 JCPDS #35-1467.

[0007] (2) Application of the WP2-P-WO3-P-Fe2O3 heterostructure nanosheet prepared by the above preparation method in water treatment reaction; in electrocatalytic decomposition of water, the reaction current density is 10mA / cm 2 , and the voltage is 1.48-1.55V; in electrocatalytic decomposition of seawater, the reaction current density is 10mA / cm 2, the voltage is 1.55-1.6V.

[0008] The present application has the following advantages:

[0009] (1) A new synthesis path of WP2-P-WO3-P-Fe2O3 heterostructure nanosheet is provided.

[0010] (2) WP2-P-WO3-P-Fe2O3 heterostructure nanosheet shows high catalytic ability in water treatment reaction. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 (a) XRD and (b) TEM characterization results of Fe2O3 nanosheet.

[0012] Figure 2 (a) XRD and (b) SEM characterization results of WO3 nanosheet.

[0013] Figure 3 XRD (a), SEM / TEM (b-f) and P (g), W (h), Fe (i), O (j) Mapping characterization results of WP2-P-WO3-P-Fe2O3 heterostructure nanosheet.

[0014] The present application has the following advantages:

[0015] 1) A new synthesis path of WP2-P-WO3-P-Fe2O3 heterostructure nanosheet is provided.

[0016] 2) WP2-P-WO3-P-Fe2O3 heterostructure nanosheet shows high catalytic ability in water treatment reaction. DETAILED DESCRIPTION

[0017] The following examples are used to further illustrate the present application, but do not limit the present application.

[0018] Example 1

[0019] Preparation of WP2-P-WO3-P-Fe2O3 heterostructure nanosheet: ① 0.5g Fe(NO3)3·9H2O was added to 50mL deionized water, and hydrothermal reaction was carried out at 160℃ in an oven for 8h, and Fe2O3 nanosheet was obtained after centrifugal drying; ② 0.6g Na2WO4·2H2O, 40mL water and 6mL concentrated hydrochloric acid were mixed, and hydrothermal reaction was carried out at 160℃ for 8h, and WO3 nanosheet was obtained after centrifugal drying; ③ 80mg Fe2O3 nanosheet prepared in the above ① and 80mg WO3 nanosheet prepared in the above ② were mixed with ethanol, and were dropped and spread on 2×3cm 2WP2-P-WO3-P-Fe2O3heterostructure nanosheets. In the above preparation method, the Fe2O3nanosheets belong to standard card JCPDS #33-0664, and the nanosheet diameter is 20-40 nm; the WO3nanosheets belong to standard card JCPDS #43-1035, and the nanosheet diameter is 80-300 nm; the WP2-P-WO3-P-Fe2O3heterostructure nanosheet diameter is 52-200 nm, and belongs to standard card WO3JCPDS #43-1035, Fe2O3JCPDS #33-0664, WP2JCPDS #35-1467. The WP2-P-WO3-P-Fe2O3heterostructure nanosheets prepared by the above preparation method are applied in water treatment reactions; in the electrocatalytic decomposition of water, the reaction current density is 10 mA / cm 2 , and the voltage is 1.48 V; in the electrocatalytic decomposition of seawater, the reaction current density is 10 mA / cm 2 , and the voltage is 1.55 V.

[0020] Example 2

[0021] Preparation of WP2-P-WO3-P-Fe2O3heterostructure nanosheets: ① 1.2 g of Fe(NO3)3·9H2O was added to 70 mL of deionized water, and hydrothermal reaction was carried out at 200°C for 20 h in an oven. After centrifugal drying, Fe2O3nanosheets were obtained; ② 0.8 g of Na2WO4·2H2O, 60 mL of water, and 8 mL of concentrated hydrochloric acid were mixed, and hydrothermal reaction was carried out at 200°C for 18 h. After centrifugal drying, WO3nanosheets were obtained; ③ 120 mg of Fe2O3nanosheets prepared in the above ① and 120 mg of WO3nanosheets prepared in the above ② were mixed with ethanol, and were dropped and spread on a commercial foam nickel-iron, which was placed in a porcelain boat. 0.8 g of NaH2PO2·H2O was placed in another porcelain boat, and was calcined at 250°C for 1 h under Ar atmosphere, with a temperature rising speed of 5°C / min, to obtain WP2-P-WO3-P-Fe2O3heterostructure nanosheets. 2WP2-P-WO3-P-Fe2O3heterostructure nanosheets. In the above preparation method, the Fe2O3nanosheets belong to standard card JCPDS #33-0664, and the nanosheet diameter is 25-46 nm; the WO3nanosheets belong to standard card JCPDS #43-1035, and the nanosheet diameter is 100-400 nm; the WP2-P-WO3-P-Fe2O3heterostructure nanosheet diameter is 60-260 nm, and belongs to standard card WO3JCPDS #43-1035, Fe2O3JCPDS #33-0664, WP2 JCPDS #35-1467. The WP2-P-WO3-P-Fe2O3heterostructure nanosheets prepared by the above preparation method are applied in water treatment reactions; in the electrocatalytic decomposition of water, the reaction current density is 10 mA / cm 2 , and the voltage is 1.55 V; in the electrocatalytic decomposition of seawater, the reaction current density is 10 mA / cm 2 , and the voltage is 1.6 V.

[0022] Example 3

[0023] Preparation of WP2-P-WO3-P-Fe2O3heterostructure nanosheets: ① 1 g of Fe(NO3)3·9H2O was added to 60 mL of deionized water, and hydrothermal reaction was carried out at 180°C for 10 h in an oven. After centrifugal drying, Fe2O3nanosheets were obtained; ② 0.7 g of Na2WO4·2H2O, 50 mL of water, and 7 mL of concentrated hydrochloric acid were mixed, and hydrothermal reaction was carried out at 180°C for 10 h. After centrifugal drying, WO3nanosheets were obtained; ③ 100 mg of Fe2O3nanosheets prepared in the above ① and 100 mg of WO3nanosheets prepared in the above ② were mixed with ethanol, and were dropped and spread on a commercial foam nickel-iron, which was placed in a porcelain boat. 1.2 g of NaH2PO2·H2O was placed in another porcelain boat, and was calcined at 400°C for 2 h under Ar atmosphere, with a temperature rising speed of 5°C / min, to obtain WP2-P-WO3-P-Fe2O3heterostructure nanosheets. 2The WP2-P-WO3-P-Fe2O3 heterostructure nanosheet is obtained by placing the commercial foamed nickel-iron on a porcelain boat, placing 1g NaH2PO2·H2O on another porcelain boat, and calcining at 300℃ for 1h under Ar atmosphere at a temperature increasing rate of 5℃ / min. The Fe2O3 nanosheet in the above preparation method belongs to standard card JCPDS #33-0664, and the nanosheet diameter is 20-46nm; the WO3 nanosheet belongs to standard card JCPDS #43-1035, and the nanosheet diameter is 80-400nm; the WP2-P-WO3-P-Fe2O3 heterostructure nanosheet diameter is 52-260nm, and belongs to standard card WO3 JCPDS #43-1035, Fe2O3 JCPDS #33-0664, and WP2 JCPDS #35-1467. The WP2-P-WO3-P-Fe2O3 heterostructure nanosheet obtained by the above preparation method is applied in water treatment reaction; in electrocatalytic decomposition of water, the reaction current density is 10mA / cm 2 , and the voltage is 1.5V; in electrocatalytic decomposition of seawater, the reaction current density is 10mA / cm 2 , and the voltage is 1.6V.

Claims

1. A method for the preparation of WP2-P-WO3-P-Fe2O3 heterostructure nanosheets for water treatment, characterized by, comprising the steps of: ① 0.5-1.2 g Fe(NO3)3·9H2O was added into 50-70 mL deionized water, and hydrothermal reaction was carried out at 160-200 ℃ in an oven for 8-20 h, and Fe2O3 nanosheets were obtained after centrifugal drying; ② 0.6-0.8 g Na2WO4·2H2O, 40-60 mL water and 6-8 mL concentrated hydrochloric acid were mixed, and hydrothermal reaction was carried out at 160-200 ℃ for 8-18 h, and WO3 nanosheets were obtained after centrifugal drying; ③ 80-120 mg Fe2O3 nanosheets prepared in the above ① and 80-120 mg WO3 nanosheets prepared in the above ② were mixed with ethanol, and were dropped and spread on 2×3 cm 2 of commercial foam nickel-iron, and were put into a porcelain boat, 0.8-1.2 g NaH2PO2·H2O was put into another porcelain boat, and WP2-P-WO3-P-Fe2O3 heterostructure nanosheets were obtained after calcination at 250-400 ℃ under Ar atmosphere for 1-2 h at a temperature rising speed of 5 ℃ / min; the Fe2O3 nanosheets belong to standard card JCPDS #33-0664, and the nanosheet diameter is 20-46 nm; the WO3 nanosheets belong to standard card JCPDS #43-1035, and the nanosheet diameter is 80-400 nm; the WP2-P-WO3-P-Fe2O3 heterostructure nanosheet diameter is 52-260 nm, and belongs to standard card WO3 JCPDS #43-1035, Fe2O3 JCPDS #33-0664 and WP2 JCPDS #35-1467.

2. The application of WP2-P-WO3-P-Fe2O3 heterostructure nanosheets prepared by the preparation method of claim 1 in water treatment reaction; in electrocatalytic decomposition of water, the reaction current density is 10 mA / cm 2 , and the voltage is 1.48-1.55 V; in electrocatalytic decomposition of seawater, the reaction current density is 10 mA / cm 2 , and the voltage is 1.55-1.6 V.

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