阅读说明：本技术 可见光响应的二氧化钛/石墨相复合光触媒水溶胶及其制备方法 (Visible light response titanium dioxide/graphite phase composite photocatalyst hydrosol and preparation method thereof ) 是由 马靖 于 2019-09-11 设计创作，主要内容包括：本发明公开了一种可见光响应的二氧化钛/石墨相复合光触媒水溶胶及其制备方法。其中所述可见光响应的二氧化钛/石墨相复合光触媒水溶胶是通过以下制备方法制备而成：S1、将尿素高温焙烧得石墨相g-C<Sub>3</Sub>N<Sub>4</Sub>,将其分散于水中；S2、将钛酸盐溶于无水乙醇中,将其缓慢滴入S1分散液中,形成TiO<Sub>2</Sub>/g-C<Sub>3</Sub>N<Sub>4</Sub>复合可见光光触媒水溶胶,用水稀释搅匀；S3、将甲醛捕获剂用水稀释、搅匀后加入到步骤S2所得水溶胶稀释液中,搅匀即得。本发明所述可见光响应的二氧化钛/石墨相复合光触媒水溶胶只需在日光或普通荧光灯照射下即可发生作用,不需额外能量,便可实现利用光能净化空气。(The invention discloses a visible light responding titanium dioxide/graphite phase composite photocatalyst hydrosol and a preparation method thereof. The visible light responding titanium dioxide/graphite phase composite photocatalyst hydrosol is prepared by the following preparation method: s1, roasting the urea at high temperature to obtain graphite phase g-C 3 N 4 Dispersing it in water; s2, dissolving titanate in absolute ethyl alcohol, and slowly dropping the titanate into the S1 dispersion to form TiO 2 /g‑C 3 N 4 Compounding the visible light photocatalyst hydrosol, diluting with water and stirring; s3, diluting the formaldehyde scavenger with water, stirring uniformly, adding into the hydrosol diluent obtained in the step S2, and stirring uniformly to obtain the formaldehyde scavenger. The visible light responding titanium dioxide/graphite phase composite photocatalyst hydrosol can act under the irradiation of sunlight or a common fluorescent lamp, and can purify air by utilizing light energy without additional energy.)

1. TiO 2₂/g-C₃N₄The composite visible light photocatalyst hydrosol is characterized by being prepared by the following method:

s1, roasting the urea at high temperature to obtain graphite phase g-C₃N₄Dispersing with water;

s2, dissolving titanate in absolute ethyl alcohol, stirring uniformly, dropping the mixture into the dispersion liquid obtained in the step S1, stirring, dissolving and mixing to obtain the titanium dioxide.

2. The TiO of claim 1₂/g-C₃N₄The composite visible light photocatalyst hydrosol is characterized in that the graphite phase g-C₃N₄The particle size of the nano-particles is 5-10 nm; preferably, the temperature range during high-temperature roasting is 500-600 ℃; preferably, the high temperature calcination time is 20 to 60 minutes.

3. The TiO of claim 1₂/g-C₃N₄The composite visible light photocatalyst hydrosol is characterized in that the graphite phase g-C₃N₄Dispersed with water in a weight ratio of 0.7-1.35: 100.

4. The TiO of claim 1₂/g-C₃N₄The composite visible light photocatalyst hydrosol is characterized in that the volume ratio of titanate to absolute ethyl alcohol in the step S2 is 1: 1.8-5.0; preferably, the volume ratio of the titanate to the absolute ethyl alcohol in the step S2 is 1: 1.8-3.8; preferably, the homogenizing speed in the step S2 is 600-800 r/m; preferably, the dropping speed in the step S2 is 45-50 g/min; preferably, the time for stirring, dissolving and mixing in the step S2 is 12-16 h.

5. The TiO of claim 1₂/g-C₃N₄The composite visible light photocatalyst hydrosol is characterized in that titanate is selected from tetrabutyl titanate, titanium isopropoxide or titanium tetrachloride.

6. TiO according to claim 1 or 2₂/g-C₃N₄The composite visible light photocatalyst hydrosol is characterized in that: the TiO is₂/g-C₃N₄TiO in composite photocatalyst₂And g-C₃N₄The weight ratio of (A) to (B) is 2: 1-1.5.

7. A titanium dioxide/graphite phase composite photocatalyst hydrosol with visible light response is characterized in that: the composition comprises the following components in parts by weight: the TiO of any one of claims 1 to 6₂/g-C₃N₄50-100 parts of composite visible light photocatalyst hydrosol, 5-10 parts of formaldehyde trapping agent and the balance of water.

8. The visible-light-responsive titanium dioxide/graphite phase composite photocatalyst hydrosol as claimed in claim 7, which is characterized in that: the formaldehyde capture agent is one or a mixture of more than two of 5, 5-dimethyl imidazolidine-2, 4-dione, carbohydrazide, urea and melamine.

9. The preparation method of the visible light response titanium dioxide/graphite phase composite photocatalyst hydrosol as claimed in claim 7 or 8, which is characterized by comprising the following steps:

1) preparing raw material components according to a formula;

2) the TiO is added₂/g-C₃N₄Diluting the visible light composite photocatalyst hydrosol with water according to the weight ratio of 6-20:1, and stirring uniformly;

3) diluting the formaldehyde capture agent with water according to the weight ratio of 1:2-6, stirring uniformly, then adding the formaldehyde capture agent into the hydrosol diluent obtained in the step 2), and stirring uniformly to obtain the formaldehyde capture agent.

10. The method for preparing the visible-light-responsive titanium dioxide/graphite phase composite photocatalyst hydrosol as claimed in claim 8, wherein the stirring speed in the step 3) is 1000-1500r/m, and the speed time is 8-10 min.

Technical Field

The invention relates to the technical field of air purification and environmental protection, in particular to a titanium dioxide/graphite phase composite photocatalyst hydrosol with visible light response and a preparation method thereof.

Background

Along with the increasing of environmental pollution, the environmental pollution brings great threat to human health, and in addition, along with the increasing of living standard of people in China, the indoor air pollution attracts more and more attention of people. The formaldehyde is a main pollutant for decoration and furniture, the release period of the formaldehyde reaches 3 to 15 years, and the formaldehyde can volatilize from deep layers of materials when meeting the damp of heat, thereby seriously polluting the environment.

Chronic respiratory diseases, nasopharyngeal carcinoma, colon cancer, leukemia and other diseases can be caused by long-term exposure to high-dose formaldehyde. Among all contaminant exposure persons, children and pregnant women are particularly sensitive to formaldehyde and are more harmful. Through the detection of indoor newly-decorated environment and artificial board furniture, a large amount of newly-decorated indoor formaldehyde generally exceeds about 80 percent, and causes the following reasons: on one hand, the formaldehyde content standard of the artificial board furniture in the industry is different from the indoor air quality standard; on the other hand, the formaldehyde exceeds the standard in a certain space due to the fact that a large number of carpentry boards and artificial board furniture are used for decoration, and the formaldehyde becomes the first major hazard of air pollution of people at home. The existing formaldehyde scavenger has the defects of short formaldehyde scavenging action time, easy rebound, high cost and the like.

Under the action of light, especially ultraviolet light, titanium dioxide not only can efficiently degrade toxic and harmful gases and kill various bacteria, but also has the functions of deodorization, pollution resistance, air purification and the like, and is a photocatalytic material with better application prospect. However, the forbidden band width of the titanium dioxide is large, and only when the ultraviolet light with the wavelength of less than 387nm is excited, electrons and holes can be generated to play the photocatalysis effect, so that the photocatalysis performance of the titanium dioxide is greatly reduced.

Therefore, there is a need to develop a photocatalyst product that can purify air by using light energy under the irradiation of sunlight or a common fluorescent lamp without using additional energy.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a titanium dioxide/graphite phase composite photocatalyst hydrosol with visible light response and a preparation method thereof. The hydrosol can act under the irradiation of sunlight or common fluorescent lamps without additional energy, and can purify air by using light energy.

The technical purpose of the invention is realized by the following technical scheme:

the invention provides a TiO compound₂/g-C₃N₄The composite visible light photocatalyst hydrosol is prepared by the following method:

s1, roasting the urea at high temperature to obtain graphite phase g-C₃N₄Dispersing with water;

s2, dissolving titanate in absolute ethyl alcohol, stirring uniformly, dropping the mixture into the dispersion liquid obtained in the step S1, stirring, dissolving and mixing to obtain the titanium dioxide.

Further, the graphite phase g-C of the invention₃N₄The particle size of the nano-particles is 5-10 nm; preferably, the temperature range during high-temperature roasting is 500-600 ℃; preferably, the high temperature calcination time is 20 to 60 minutes.

Further, the graphite phase g-C of the invention₃N₄Dispersed with water in a weight ratio of 0.7-1.35: 100.

Further, the volume ratio of titanate to absolute ethyl alcohol in the step S2 is 1: 1.8-5.0; preferably, the volume ratio of the titanate to the absolute ethyl alcohol in the step S2 is 1: 1.8-3.8; preferably, the homogenizing speed in the step S2 is 600-800 r/m; preferably, the dropping speed in the step S2 is 45-50 g/min; preferably, the time for stirring, dissolving and mixing in the step S2 is 12-16 h.

Preferably, the titanate according to the invention is selected from n-tetrabutyltitanate, titanium isopropoxide or titanium tetrachloride.

Further, the TiO of the present invention₂/g-C₃N₄TiO in composite photocatalyst₂And g-C₃N₄The weight ratio of (A) to (B) is 2: 1-1.5.

The invention also aims to provide a visible light responding titanium dioxide/graphite phase composite photocatalyst hydrosol which comprises the following components in parts by weight: the TiO of any one of claims 1 to 6₂/g-C₃N₄50-100 parts of composite visible light photocatalyst hydrosol, 5-10 parts of formaldehyde trapping agent and the balance of water. Preferably, the weight part of the water is 29-33 parts.

Further, the formaldehyde trapping agent is one or a mixture of more than two of 5, 5-dimethyl imidazolidine-2, 4-dione, carbohydrazide, urea and melamine.

The invention also aims to provide a preparation method of the visible light response titanium dioxide/graphite phase composite photocatalyst hydrosol, which is characterized by comprising the following steps:

1) preparing raw material components according to a formula;

2) the TiO is added₂/g-C₃N₄Diluting the visible light composite photocatalyst hydrosol with water according to the weight ratio of 6-20:1, and stirring uniformly;

3) diluting the formaldehyde capture agent with water according to the weight ratio of 1:2-6, stirring uniformly, then adding the formaldehyde capture agent into the hydrosol diluent obtained in the step 2), and stirring uniformly to obtain the formaldehyde capture agent.

Furthermore, the stirring speed in the step 3) of the invention is 1000-.

By adopting the technical scheme, the invention has the beneficial effects that:

by reacting with TiO₂The doping is carried out, the exciting light of the photocatalyst is widened from ultraviolet to a visible region, the utilization range of the titanium dioxide/graphite phase composite photocatalyst responding to visible light to light is greatly improved, and the air purification efficiency and the sterilization efficiency of the photocatalyst are more effectively improved.

Drawings

FIG. 1a is g-C according to the invention₃N₄A structural characterization diagram under an electron microscope with the resolution of 50 nm; FIG. 1b is a structural representation of the visible light responsive titanium dioxide/graphite phase composite photocatalyst hydrosol of the present invention under an electron microscope with a resolution of 0.2 μm; FIG. 1c is an enlarged structural representation view of the visible light responsive titanium dioxide/graphite phase composite photocatalyst hydrosol under an electron microscope with a resolution of 50 nm.

FIG. 2 shows the absorbance of the visible light-responsive titanium dioxide/graphite phase composite photocatalyst hydrosol.

FIG. 3 shows the degradation performance of the visible light responsive titanium dioxide/graphite phase composite photocatalyst hydrosol product of the invention on pollutants (the concentration of formaldehyde in the pollutants is 1.0 mg/m)³Natural light).

Fig. 4 shows the degradation performance of the visible light responsive titanium dioxide/graphite phase composite photocatalyst hydrosol of the invention on pollutants under the trigger of indoor light.

Fig. 5 shows the degradation cycle performance of the visible light responsive titanium dioxide/graphite phase composite photocatalyst hydrosol of the invention on pollutants under the trigger of indoor light.

Detailed Description

The present invention will be described in more detail with reference to specific preferred embodiments, but the present invention is not limited to the following embodiments.

The visible light responding titanium dioxide/graphite phase composite photocatalyst hydrosol is prepared by modifying titanium dioxide by a doping method so as to improve the photocatalytic activity of the titanium dioxide in a visible light region. The titanium dioxide is doped with rare earth metal, so that the sunlight absorption of a titanium dioxide semiconductor can be widened, and due to the special 4f electronic configuration of the rare earth metal ions, effective complexation can be formed between the rare earth metal ions and some pollutants, so that the reaction speed of the rare earth metal ions and surface photon-generated carriers is accelerated.

Tetrabutyl titanate is a commercial product, and the density of the tetrabutyl titanate is 0.99 g/ml; titanium tetrachloride is a commercial product and has the density of 1.73 g/ml; titanium isopropoxide is a commercially available product and has a density of 0.95 g/ml.