CN103611558B

CN103611558B - Bi2WO6-BaTaO2N composite photocatalyst and preparation method thereof

Info

Publication number: CN103611558B
Application number: CN201310644494.2A
Authority: CN
Inventors: 吕华; 刘玉民; 汤海波; 李紫金; 李爽; 丁志伟
Original assignee: Henan Normal University
Current assignee: Henan Normal University
Priority date: 2013-12-05
Filing date: 2013-12-05
Publication date: 2015-07-08
Anticipated expiration: 2033-12-05
Also published as: CN103611558A

Abstract

The invention discloses a Bi2WO6-BaTaO2N composite photocatalyst and a preparation method thereof, belonging to the field of inorganic functional materials. The technical scheme is as follows: the Bi2WO6-BaTaO2N composite photocatalyst is compounded from Bi2WO6 powder and BaTaO2N powder in a mole ratio of (6-15):1. The invention also discloses a preparation method of the Bi2WO6-BaTaO2N composite photocatalyst. Compared with the prior art, the Bi2WO6-BaTaO2N composite photocatalyst has the following advantages: the compounding of the Bi2WO6 and BaTaO2N can greatly widen the spectral response range of the Bi2WO6, so that the Bi2WO6 has favorable absorptivity in the visible light region, thereby enhancing the utilization ratio of solar energy; the compounding of the Bi2WO6 and BaTaO2N can effectively reduce the compound probability between photogenerated electrons and holes, and enhance the photocatalytic activity of the Bi2WO6; and the preparation method of the Bi2WO6-BaTaO2N composite photocatalyst is simple and easy to control.

Description

A kind of Bi 2wO 6-BaTaO 2n composite photo-catalyst and preparation method thereof

Technical field

The invention belongs to inorganic environment-friendly catalysis material technical field, be specifically related to a kind of Bi ₂wO ₆-BaTaO ₂n composite photo-catalyst and preparation method thereof.

Background technology

Along with the progress of social development and industry, various poisonous, noxious pollutant is constantly accumulation and transfer in the environment such as air, water and soil, and the heavy damage ecological balance, also endangers the health of the mankind simultaneously.In recent years, the advantages such as efficiency is high, energy consumption is low, reaction condition is gentle, applied widely and secondary pollution is few that utilize Nano semiconductor photocatalysis degradation organic contaminant to have, cause the attention of increasing researcher.Compared with the methods such as traditional burning, biodegradation, photocatalysis technology efficiency is high, practical, and secondary pollution is few, is a kind of effective way of thing of curbing environmental pollution.

Traditional catalysis material is as TiO ₂, ZnO etc. can only absorb ultraviolet light, spectral response range is narrow, limits their practical application.In order to make full use of abundant solar energy, research has highly active catalysis material under visible light and has important practical significance.Bi ₂wO ₆be a kind ofly novel have visible light-responded catalysis material, its energy gap is 2.8 eV, and absorbing wavelength can be less than the visible ray of 442 nm, be that one has high performance visible-light photocatalysis material.But, Bi ₂wO ₆the hole produced after photochemical catalyst optical excitation and the probability of electron recombination high, quantum effect is low, and photocatalytic activity is low.Therefore, the Focal point and difficult point that its photo-quantum efficiency and photocatalytic activity become photocatalysis disciplinary study is improved.

BaTaO ₂n is a kind of transition metal oxynitrides, and because divalence oxygen element part is replaced by the trivalent nitrogen element that electronegativity is less, metal cation is more or less reduced, and crystal structure changes, BaTaO ₂thus N shows optical, electrical, the magnetic that make new advances, mechanical property.Research shows, BaTaO ₂the energy gap of N is 2.0 eV, and energy absorbing wavelength is less than the visible ray of 620 nm, is a kind of catalysis material with visible light-responded ability.In order to improve Bi ₂wO ₆photo-quantum efficiency, by itself and the BaTaO with ideal bandgap ₂n phase compound, utilizes the energy level difference between two kinds of semiconductors that photogenerated carriers can be made to be injected on the energy level of another kind of semiconductor by a kind of energy level of semiconductive particles, electric charge is effectively separated, and is to improve Bi ₂wO ₆the effective way of solar energy utilization ratio and photo-quantum efficiency.Bi ₂wO ₆the conduction band potential E of photochemical catalyst _cB=0.46 eV, valence band electromotive force E _vB=3.26 eV, and BaTaO ₂the conduction band potential E of N photochemical catalyst _cB=-0.44 eV, valence band electromotive force E _vB=1.56 eV.At Bi ₂wO ₆-BaTaO ₂in N composite semiconductor, BaTaO ₂the conduction band potential of N is more negative, and light induced electron is easily from the BaTaO that energy level is low ₂n conduction band moves to the high Bi of energy level ₂wO ₆on conduction band, meanwhile, Bi ₂wO ₆valence band electromotive force corrigendum, photohole is easily from the Bi that energy level is high ₂wO ₆valence band moves to the low BaTaO of energy level ₂in N valence band, thus improve the separative efficiency of photogenerated charge, extend Bi ₂wO ₆spectral response range.

Summary of the invention

The technical problem that the present invention solves there is provided the Bi that a kind of photo-quantum efficiency is high, photocatalytic activity is good ₂wO ₆-BaTaO ₂n composite photo-catalyst.

The present invention solve another technical problem there is provided a kind of simple to operate and be easy to control Bi ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst.

Technical scheme of the present invention is: a kind of Bi ₂wO ₆-BaTaO ₂n composite photo-catalyst, it is characterized in that by Bi ₂wO ₆with BaTaO ₂n powder compound and the Bi formed ₂wO ₆-BaTaO ₂n composite photo-catalyst, wherein Bi ₂wO ₆with BaTaO ₂the mol ratio of N is 6-15:1.

Bi of the present invention ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst, it is characterized in that comprising the following steps: the ratio of tantalum pentoxide, brium carbonate and acetone 1:2:15 in molar ratio to be joined in agate mortar grinding evenly by (1), then sample is evenly laid on corundum boat, load in tube-type atmosphere furnace, under ammonia atmosphere, 950 DEG C of calcinings obtain BaTaO in 20 hours ₂n powder; (2) ammonium tungstate solution is prepared, by step (1) gained BaTaO under the condition stirred ₂n powder joins in ammonium tungstate solution and obtains mixed solution A, wherein ammonium tungstate and the BaTaO added ₂the mol ratio of N powder is 6-15:1; (3) prepare bismuth nitrate solution, joined by bismuth nitrate solution in mixed solution A and obtain mixed solution B under the condition stirred, wherein in mixed solution A, ammonium tungstate is 2:1 with the mol ratio of the bismuth nitrate added; (4) regulate the pH value of mixed solution B to be 2-9 with nitric acid or ammoniacal liquor, then mixed solution B is moved in hydrothermal reaction kettle, after keeping 6-36 hour at 180-240 DEG C, obtain having the Bi of high catalytic activity through coldly going, filtering, wash, after drying ₂wO ₆-BaTaO ₂n composite photo-catalyst.

Bi of the present invention ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst, is characterized in that: in described step (2), the molar concentration of ammonium tungstate solution is 0.01-0.05mol/L.Bi of the present invention ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst, is characterized in that: in described step (3), the molar concentration of bismuth nitrate solution is 0.1-0.3mol/L.

The present invention compared with prior art has following remarkable advantage: 1, Bi ₂wO ₆with BaTaO ₂the compound of N can widen Bi greatly ₂wO ₆spectral response range, make Bi ₂wO ₆there is good absorption in visible region, improve the utilization rate of solar energy; 2, Bi ₂wO ₆with BaTaO ₂the compound of N can effectively reduce the probability of recombination in light induced electron and hole, improves Bi ₂wO ₆photocatalytic activity; 3, Bi of the present invention ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst is simple, is easy to control.

Accompanying drawing explanation

Fig. 1 is under 300W xenon lamp irradiates, the Bi prepared by the embodiment of the present invention 1 ₂wO ₆-BaTaO ₂n photochemical catalyst and pure Bi ₂wO ₆light urges agent to the correlation curve figure (operating condition: the amount of catalyst: 1 g/L of rhodamine B degraded situation; The concentration of rhodamine B: 5 mg/L).

Detailed description of the invention

The present invention is further described below in conjunction with embodiment.It is noted that the present invention is not limited to following each embodiment.

Embodiment 1

(1) amount of substance is respectively the tantalum pentoxide of 0.0005mol, 0.001mol, 0.075mol, brium carbonate and acetone and joins in agate mortar grinding evenly, then sample is evenly laid on corundum boat, load in tube-type atmosphere furnace, under ammonia atmosphere, 950 DEG C of calcinings obtain BaTaO in 20 hours ₂n powder;

(2) the ammonium tungstate solution 50mL that molar concentration is 0.01mol/L is prepared, under agitation by step (1) gained BaTaO ₂n powder joins in ammonium tungstate solution and obtains mixed solution A;

(3) prepare the bismuth nitrate solution 120mL that molar concentration is 0.1mol/L, bismuth nitrate solution is joined in mixed solution A under the condition stirred and obtain mixed solution B;

(4) regulate the pH value of mixed solution B to be 2.0 with nitric acid, then mixed solution B is moved in hydrothermal reaction kettle, after keeping 36 hours at 180 DEG C, obtain having the Bi of high catalytic activity through coldly going, filtering, wash, after drying ₂wO ₆-BaTaO ₂n composite photo-catalyst.

Embodiment 2

(2) the ammonium tungstate solution 50mL that molar concentration is 0.02mol/L is prepared, by step (1) gained BaTaO under the condition stirred ₂n powder joins in ammonium tungstate solution and obtains mixed solution A;

(3) prepare the bismuth nitrate solution 120mL that molar concentration is 0.2mol/L, bismuth nitrate solution is joined in mixed solution A under the condition stirred and obtain mixed solution B;

(4) regulate the pH value of mixed solution B to be 5.0 with nitric acid, then mixed solution B is moved in hydrothermal reaction kettle, after keeping 12 hours at 200 DEG C, obtain having the Bi of high catalytic activity through coldly going, filtering, wash, after drying ₂wO ₆-BaTaO ₂n composite photo-catalyst.

Embodiment 3

(2) the ammonium tungstate solution 25mL that molar concentration is 0.05mol/L is prepared, under agitation by step (1) gained BaTaO ₂n powder joins in ammonium tungstate solution and obtains mixed solution A;

(3) prepare the bismuth nitrate solution 100mL that molar concentration is 0.3mol/L, bismuth nitrate solution is joined in mixed solution A under the condition stirred and obtain mixed solution B;

(4) regulate the pH value of mixed solution B to be 9.0 with ammoniacal liquor, then mixed solution B is moved in hydrothermal reaction kettle, after keeping 6 hours at 240 DEG C, obtain having the Bi of high catalytic activity through coldly going, filtering, wash, after drying ₂wO ₆-BaTaO ₂n composite photo-catalyst.

Embodiment above describes general principle of the present invention, principal character and advantage.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and description just illustrates principle of the present invention; under the scope not departing from the principle of the invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the scope of protection of the invention.

Claims

1. a Bi ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst, it is characterized in that specifically comprising the following steps: the ratio of tantalum pentoxide, brium carbonate and acetone 1:2:15 in molar ratio to be joined in agate mortar grinding evenly by (1), then sample is evenly laid on corundum boat, load in tube-type atmosphere furnace, under ammonia atmosphere, 950 DEG C of calcinings obtain BaTaO in 20 hours ₂n powder; (2) ammonium tungstate solution is prepared, by step (1) gained BaTaO under the condition stirred ₂n powder joins in ammonium tungstate solution and obtains mixed solution A, wherein ammonium tungstate and the BaTaO added ₂the mol ratio of N powder is 6-15:1; (3) prepare bismuth nitrate solution, joined by bismuth nitrate solution in mixed solution A and obtain mixed solution B under the condition stirred, wherein in mixed solution A, ammonium tungstate is 2:1 with the mol ratio of the bismuth nitrate added; (4) regulate the pH value of mixed solution B to be 2-9 with nitric acid or ammoniacal liquor, then mixed solution B is moved in hydrothermal reaction kettle, after keeping 6-36 hour at 180-240 DEG C, after cooling, filtration, washing, drying, obtain the Bi with high catalytic activity ₂wO ₆-BaTaO ₂n composite photo-catalyst.

2. Bi according to claim 1 ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst, is characterized in that: in step (2), the molar concentration of ammonium tungstate solution is 0.01-0.05mol/L.

3. Bi according to claim 1 ₂wO ₆-BaTaO ₂the preparation method of N composite photo-catalyst, is characterized in that: in step (3), the molar concentration of bismuth nitrate solution is 0.1-0.3mol/L.