阅读说明：本技术 银-二氧化钛-纳米金刚石复合光催化剂的制备方法及其应用 (Preparation method and application of silver-titanium dioxide-nano diamond composite photocatalyst ) 是由 苏丽霞 郝好山 李瑞雪 王文闯 于 2019-10-24 设计创作，主要内容包括：本发明公开了一种银-二氧化钛-纳米金刚石复合光催化剂的制备方法及其应用,在纳米金刚石溶液中加入TiO<Sub>2</Sub>的前驱体(NH4)<Sub>2</Sub>TiF<Sub>6</Sub>和H<Sub>3</Sub>BO<Sub>3</Sub>,在磁力搅拌下,加热至50℃~80℃并保温1~2小时,然后在N<Sub>2</Sub>气氛下,继续加热至180℃~200℃保温1~2小时,得到二氧化钛-纳米金刚石(TiO<Sub>2</Sub>-ND)样品；取TiO<Sub>2</Sub>-ND样品加入去离子水,然后缓慢加入AgNO<Sub>3</Sub>溶液,在磁力搅拌下,紫外灯(UV)辐照混合溶液2h,水洗,干燥即得到银-二氧化钛-纳米金刚石复合光催化剂。本发明构筑的Ag/TiO<Sub>2</Sub>-ND因具有较好的载流子传输通道从而有较好的载流子分离效率,最终导致载流子利用效率好,光催化效率好。(The invention discloses a preparation method and application of a silver-titanium dioxide-nano diamond composite photocatalyst 2 precursor (NH4) 2 TiF 6 And H 3 BO 3 Heating to 50 ℃ ~ 80 ℃ and holding for 1 ~ 2 hours under magnetic stirring, and then stirring in N 2 Continuously heating to 180 ℃, ~ 200 ℃ and 200 ℃ under the atmosphere, and preserving the heat for 1 ~ 2 hours to obtain the titanium dioxide-nano diamond (TiO) 2 -ND) a sample; taking TiO 2 Adding deionized water to the ND sample, and then slowly adding AgNO 3 And (3) irradiating the mixed solution for 2 hours by using an ultraviolet lamp (UV) under the magnetic stirring, washing with water, and drying to obtain the silver-titanium dioxide-nano diamond composite photocatalyst. Ag/TiO constructed by the invention 2 The ND has better carrier separation efficiency due to better carrier transmission channel, and finally leads to carrier utilization efficiencyGood photocatalytic efficiency.)

1. A preparation method of a silver-titanium dioxide-nano diamond composite photocatalyst is characterized by comprising the following steps:

(1) Processing the nano-diamond, namely putting the nano-diamond in a crucible, processing the nano-diamond for 0.5 ~ 2 hours at the temperature of 420 ℃ and ~ 430 ℃ under the air atmosphere, and naturally cooling the nano-diamond to room temperature;

(2) Preparing titanium dioxide-nano diamond: dissolving the nano-diamond obtained in the step (1) in deionized water, carrying out ultrasonic treatment for 1 hour, and slowly adding TiO into the solution₂precursor (NH4)₂TiF₆and H₃BO₃heating to 50 ℃ ~ 80 ℃ and holding for 1 ~ 2 hours under magnetic stirring, and then stirring in N₂Continuously heating to 180 ℃ and ~ 200 ℃ under the atmosphere, preserving the heat for 1 ~ 2 hours, finally naturally cooling to room temperature, and cleaning for a plurality of times by deionized water and ethanol to obtain a titanium dioxide-nano diamond sample;

(3) Preparing a silver-titanium dioxide-nano diamond composite photocatalyst: taking the TiO prepared in the step (2)₂Adding deionized water into the-ND sample, magnetically stirring for 30 min, and slowly adding AgNO₃ and (3) irradiating the mixed solution for 2 hours by using an ultraviolet lamp under magnetic stirring, centrifuging the obtained solution, washing the solution for a plurality of times by using deionized water and ethanol, then putting the washed sample into a blast drying oven, and keeping the temperature at 60 ℃ for 2 hours to obtain the silver-titanium dioxide-nano diamond composite photocatalyst.

2. The method for preparing the silver-titanium dioxide-nanodiamond composite photocatalyst according to claim 1, wherein the method comprises the following steps: the nano-diamond in the step (1) is commercially purchased nano-diamond with the size less than 10 nm.

3. The method for preparing the silver-titanium dioxide-nanodiamond composite photocatalyst according to claim 1, wherein the method comprises the following steps: controlling TiO in the step (2)₂Precursor (NH4)₂TiF₆And H₃BO₃So that the quantity ratio of the nano-diamond to the titanium dioxide substance is ND to TiO₂=1:（5-15）。

4. The method for preparing the silver-titanium dioxide-nanodiamond composite photocatalyst according to claim 3, wherein the method comprises the following steps: controlling TiO in the step (2)₂Precursor (NH4)₂TiF₆And H₃BO₃So that the quantity ratio of the nano-diamond to the titanium dioxide substance is ND to TiO₂=1:10。

5. The method for preparing the silver-titanium dioxide-nanodiamond composite photocatalyst according to claim 1, wherein the method comprises the following steps: AgNO in the step (3)₃The concentration of the solution is 1mol/L, and AgNO is controlled₃ The solution is added in such an amount that Ag is mixed with TiO₂The mass ratio of-ND is 1 (5-40).

6. the method for preparing the silver-titanium dioxide-nanodiamond composite photocatalyst according to claim 5, wherein the method comprises the following steps: AgNO in the step (3)₃The concentration of the solution is 1mol/L, and AgNO is controlled₃ the solution is added in such an amount that Ag is mixed with TiO₂Mass ratio of-ND 1: 20.

7. The use of the silver-titanium dioxide-nanodiamond composite photocatalyst prepared by the preparation method of any one of claims 1-6 in photodegradation.

Technical Field

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a preparation method and application of a silver-titanium dioxide-nano diamond composite photocatalyst.

background

With the development of science and technology and the progress of society, environmental pollution becomes a more and more serious problem. Solving the problem of water pollution at a lower cost remains a challenge. The method for decomposing the solar pollutants into harmless micromolecules by adopting the semiconductor photocatalysis technology is favored by the majority of scientific research enthusiasts. However, poor photon absorption capability and low photon-generated carrier separation efficiency are two major problems faced by the current photocatalytic pollutant degradation technology. Titanium dioxide (TiO)₂) As a classical photocatalytic material, there are many methods for optimizing the photocatalytic efficiency, such as element doping, heterojunction formation, noble metal (gold (Au), silver (Ag), and the like) modification. The construction of three-component photocatalyst, through the synergistic effect of different components, the composite material shows better photocatalytic activity, which is one of the methods for preparing excellent photocatalyst. In recent years, as a novel carbon nanomaterial, Nanodiamond (ND) has a wide application prospect in the field of photocatalysis due to its characteristics of large specific surface area, easy surface modification, light scattering effect and the like.

Disclosure of Invention

Aiming at the problems faced by the existing photocatalytic pollutant degradation technology, the invention provides a preparation method of a silver-titanium dioxide-nano diamond composite photocatalyst and application thereof in photodegradation. Under the irradiation of simulated sunlight, Ag/TiO₂Photodegradation of ND RhB reaction Rate constant (0.172 min)^-1) Is TiO₂(0.035 min)^-1) 4.9 times.

In order to solve the technical problems, the invention adopts the following technical scheme:

A preparation method of a silver-titanium dioxide-nano diamond composite photocatalyst comprises the following steps:

(1) Treating the nano-diamond (ND), namely placing the nano-diamond (ND) in a crucible, treating for 0.5 ~ 2 hours at the temperature of 420 ℃ and ~ 430 ℃ under the air atmosphere, and naturally cooling to room temperature;

(2) Titanium dioxide-nanodiamond (TiO)₂-ND) preparation: dissolving the nano-diamond obtained in the step (1) in deionized water, carrying out ultrasonic treatment for 1 hour, and slowly adding TiO into the solution₂precursor (NH4)₂TiF₆And H₃BO₃Heating to 50 ℃ ~ 80 ℃ and holding for 1 ~ 2 hours under magnetic stirring, and then stirring in N₂Continuously heating to 180 ℃ and ~ 200 ℃ under the atmosphere, preserving heat for 1 ~ 2 hours, finally naturally cooling to room temperature, and cleaning for a plurality of times by deionized water and ethanol to obtain the titanium dioxide-nano diamond (TiO)₂-ND) a sample;

(3) Preparing a silver-titanium dioxide-nano diamond composite photocatalyst: taking the TiO prepared in the step (2)₂adding deionized water into the-ND sample, magnetically stirring for 30 min, and slowly adding AgNO₃ And (3) irradiating the mixed solution for 2 hours by using an ultraviolet lamp (UV) under magnetic stirring, centrifuging the obtained solution, washing the solution for a plurality of times by using deionized water and ethanol, then putting the washed sample into a blast drying oven, and preserving heat at 60 ℃ for 2 hours to obtain the silver-titanium dioxide-nano diamond composite photocatalyst.

Further, the nanodiamonds in the step (1) are commercially available nanodiamonds having a size of less than 10 nm.

Further, controlling TiO in the step (2)₂Precursor (NH4)₂TiF₆And H₃BO₃So that the quantity ratio of the nano-diamond to the titanium dioxide substance is ND to TiO₂=1 (5-15), preferably 1: 10.

Further, AgNO in the step (3)₃The concentration of the solution is 1mol/L, and AgNO is controlled₃ The solution is added in such an amount that Ag is mixed with TiO₂The mass ratio of-ND is 1 (5-40), preferably 1: 20.

The silver-titanium dioxide-nano diamond composite photocatalyst prepared by the preparation method is applied to photodegradation.

The invention has the beneficial effects that: 1. Ag/TiO of the present invention₂Better photon-generated carrier transfer is constructed in the-ND three-component composite photocatalytic materialEnrichment channel, TiO₂The generated photogenerated carriers are rapidly transferred to the surface of Ag nano particles and then transferred to the ND surface, so that the carriers and Ag/TiO are mixed₂Compared with the prior art, the method has the advantages of higher separation efficiency of photon-generated carriers and higher photocatalytic activity. 2. The present invention is typical of two-component heterojunctions, such as TiO₂the/ND can promote the separation efficiency of photogenerated carriers, but the separated carriers can be randomly compounded before not participating in the reaction to construct three-component Ag/TiO₂ND, Ag can rapidly capture TiO₂the generated light generates electrons and transfers the electrons to the ND, thus reducing the probability of electron-hole recombination. Thus, the Ag/TiO thus constructed₂the-ND has better carrier separation efficiency due to better carrier transmission channel, and finally, the carrier utilization efficiency and the photocatalysis efficiency are good. 3. The composite photocatalyst has better catalytic activity of photodegradable pollutants rhodamine B (RhB). Under the irradiation of simulated sunlight, Ag/TiO₂Photodegradation of ND RhB reaction Rate constant (0.172 min)^-1) Is TiO₂(0.035 min)^-1) 4.9 times.

Drawings

FIG. 1 is a graph comparing the degradation rates of different photocatalysts on RhB.

FIG. 2 shows Ag/TiO in simulated solar radiation₂And degrading RhB by the ND photocatalyst, and obtaining the ultraviolet-visible absorption spectrum of the RhB aqueous solution corresponding to different catalysis times.

Detailed Description

The present invention will be further described with reference to the following examples. It is to be understood that the following examples are illustrative only and are not intended to limit the scope of the invention, which is to be given numerous insubstantial modifications and adaptations by those skilled in the art based on the teachings set forth above.