阅读说明：本技术 镧系金属掺杂TiO2中空纳米盒子催化剂及其制备方法、应用 (Lanthanide metal doped TiO2Hollow nano-box catalyst, and preparation method and application thereof ) 是由 义国通 农时锋 陆燕 黎施展 于 2021-11-08 设计创作，主要内容包括：一种镧系金属掺杂TiO-(2)中空纳米盒子催化剂的制备方法,首先获得镧系金属离子掺杂的CaTiO-(3)立方体,再通过鳌合反应原位转化成了镧掺杂的TiO-(2),最后通过煅烧获得具有稳定晶型的空心盒子。本发明通过形貌调控制得具有空心盒子状结构的TiO-(2),具有较大的比表面积,同时镧系金属离子掺杂减少了光生载流子的复合,使催化剂具有更高的催化活性,具有高活性、低成本、操作简单、安全、重复性强、操作工艺参数易控的优点,能够对新烟碱类农药进行有效处理,避免二次污染。(Lanthanide metal doped TiO 2 The preparation method of hollow nano-box catalyst comprises the steps of firstly obtaining lanthanide series metal ion doped CaTiO 3 Cubic bodies, and in situ converted to lanthanum-doped TiO by chelation 2 And finally, obtaining the hollow box with the stable crystal form by calcining. The TiO with the hollow box-shaped structure is prepared by regulating the shape 2 Has large specific surface area and lanthanide series metalThe ion doping reduces the recombination of photon-generated carriers, so that the catalyst has higher catalytic activity, has the advantages of high activity, low cost, simple and safe operation, strong repeatability and easily controlled operation process parameters, can effectively treat the neonicotinoid pesticide, and avoids secondary pollution.)

1. Lanthanide metal doped TiO₂The preparation method of the hollow nano-box catalyst is characterized by comprising the following steps of:

s1, dissolving 0.44g of calcium chloride dihydrate into a mixed solvent of 12-16 ml of polyethylene glycol-200 and 40-50 ml of absolute ethyl alcohol, uniformly mixing to obtain a first mixed solution, adding lanthanide hydrated nitrate into the first mixed solution under a stirring state, uniformly stirring, then adding tetrabutyl titanate, completely dissolving, adding 0.9-1 g of sodium hydroxide, and stirring for 1h to obtain a mixture;

s2, transferring the mixture obtained in the step S1 to a 100ml high-pressure reaction kettle, reacting at 180 ℃ for 12-16 h, cooling to room temperature, washing the obtained product with deionized water and absolute ethyl alcohol respectively, drying, and grinding to obtain a sample;

s3, dissolving 0.3g of S2 sample in a mixed solvent of 12-16 ml of ethylene glycol and 40-50 ml of deionized water, adding 1.2-1.4 g of EDTA-2Na after uniformly stirring, transferring the mixture into a 100ml high-pressure reaction kettle after uniformly stirring, reacting in an oven at 180 ℃ for 12-16 h, and cooling to room temperature after the chelation reaction is finished;

s4 is washed by absolute ethyl alcohol and deionized water through vacuum filtration respectively, then dried in a drying oven, and is transferred into a muffle furnace for heating after being fully ground, thus obtaining lanthanide metal doped TiO₂Hollow nano-box catalysts.

2. The lanthanide metal doped TiO of claim 1₂The preparation method of the hollow nano-box catalyst is characterized in that the molar ratio of tetrabutyl titanate to lanthanide hydrated nitrate in S1 is 20: 1.

3. the lanthanide metal doped TiO of claim 1₂The preparation method of the hollow nano-box catalyst is characterized in that the volume ratio of ethylene glycol to deionized water in S3 is 1: 3.

4. The lanthanide metal doped TiO of claim 1₂The preparation method of the hollow nano-box catalyst is characterized in that the catalyst in S4 is transferred into a muffle furnace to be heated to 400 ℃ at a heating rate of 5 ℃/min and then is kept for 2 h.

5. The lanthanide metal-doped TiO as claimed in any one of claims 1 to 4₂Lanthanide metal doped TiO prepared by preparation method of hollow nano box catalyst₂The hollow nano-box catalyst is characterized in that the doped metal is at least one of La, Ce, Sm, Yb and Tm.

6. Lanthanide metal doped TiO₂Application of the hollow nano-box catalyst in degradation of neonicotinoid pesticides.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of nano materials and photocatalysis, and relates to lanthanide metal doped TiO₂A hollow nanometer box catalyst, a preparation method and an application thereof.

[ background of the invention ]

Pesticides are widely used in agriculture as a chemical, but the over-utilization of pesticides pollutes water sources and soil, and organic pollutants can be accumulated in biological tissues, thereby causing serious threats to the health of human beings and animals. The pyridinamide and the imidacloprid belong to neonicotinoid high-efficiency insecticides and are the most widely used insecticides in the world, but the pyridinamide and the imidacloprid have attracted wide attention due to the problems of high solubility in water, easy accumulation, difficult self-degradation in the environment and the like. Therefore, it is important to find an effective method for reducing the residue and accumulation of neonicotinoid pesticides.

In the past, it has been known that various methods for solving the problem of the residue and accumulation of neonicotinoid pesticides have been explored. The main methods include microbial degradation, electrocatalysis, plasma technology, etc. However, these methods generally have the disadvantages of high cost, high energy consumption, easy environmental impact, easy secondary pollution, etc.

[ summary of the invention ]

In order to solve the problems, the invention provides lanthanide metal doped TiO with high activity, low cost, simple operation, safety, strong repeatability and easily controlled operation process parameters₂The hollow nanometer box catalyst can effectively treat the neonicotinoid pesticides and avoid secondary pollution.

The invention is realized by the following technical scheme, and provides lanthanide metal doped TiO₂The preparation method of the hollow nano-box catalyst comprises the following steps:

s1, dissolving 0.44g of calcium chloride dihydrate into a mixed solvent of 12-16 ml of polyethylene glycol-200 and 40-50 ml of absolute ethyl alcohol, uniformly mixing to obtain a first mixed solution, adding lanthanide hydrated nitrate into the first mixed solution under a stirring state, uniformly stirring, then adding tetrabutyl titanate, completely dissolving, adding 0.9-1 g of sodium hydroxide, and stirring for 1h to obtain a mixture;

s2, transferring the mixture obtained in the step S1 to a 100ml high-pressure reaction kettle, reacting at 180 ℃ for 12-16 h, cooling to room temperature, washing the obtained product with deionized water and absolute ethyl alcohol respectively, drying, and grinding to obtain a sample;

s3, dissolving 0.3g of S2 sample in a mixed solvent of 12-16 ml of ethylene glycol and 40-50 ml of deionized water, adding 1.2-1.4 g of EDTA-2Na after uniformly stirring, transferring the mixture into a 100ml high-pressure reaction kettle after uniformly stirring, reacting in an oven at 180 ℃ for 12-16 h, and cooling to room temperature after the chelation reaction is finished;

s4 is washed by absolute ethyl alcohol and deionized water through vacuum filtration respectively, then dried in a drying oven, and is transferred into a muffle furnace for heating after being fully ground, thus obtaining lanthanide metal doped TiO₂Hollow nano-box catalysts.

In particular, the mole ratio of tetrabutyl titanate to lanthanide hydrated nitrate in the S1 is 20: 1.

specifically, the volume ratio of the ethylene glycol to the deionized water in the S3 is 1: 3.

Specifically, the mixture in S4 is transferred into a muffle furnace to be heated to 400 ℃ at a heating rate of 5 ℃/min and then is kept for 2 h.

The invention also provides lanthanide metal doped TiO prepared by the method₂The doped metal is at least one of La, Ce, Sm, Yb and Tm.

The invention also provides lanthanide metal doped TiO₂Application of the hollow nano-box catalyst in degradation of neonicotinoid pesticides.

The invention provides lanthanide metal doped TiO₂A preparation method of a hollow nano-box catalyst utilizes a self-sacrifice template method to synthesize TiO with a hollow layered cubic box shape₂Firstly, obtaining the lanthanide metal ion doped CaTiO₃Cubic bodies, and in situ converted to lanthanum-doped TiO by chelation₂Finally obtaining the tool by calciningA hollow box with stable crystal form. The TiO with the hollow box-shaped structure is prepared by regulating the shape₂The catalyst has a large specific surface area, and lanthanide metal ions are doped to reduce the recombination of photon-generated carriers, so that the catalyst has higher catalytic activity.

[ description of the drawings ]

FIG. 1 shows a lanthanide metal doped TiO compound of the present invention₂XRD pattern of hollow nano-box catalyst;

FIG. 2 is a scanning electron microscope photograph of an embodiment of the present invention;

FIG. 3 is a transmission electron microscope photograph of an embodiment of the present invention;

FIG. 4 is a diagram illustrating the photocatalytic degradation effect according to an embodiment of the present invention.

[ detailed description ] embodiments

In order to make the objects, technical solutions and advantages of the present invention more clear, the following experiments were conducted in two groups, wherein the first group is the example group and examples 1-6, and the other group is the experiment group and examples 7-12, and the activity of the catalysts prepared in the examples were respectively tested.

Example 1

Dissolving 0.44g of calcium chloride dihydrate in a mixed solvent of 15ml of polyethylene glycol-200 and 45ml of absolute ethyl alcohol, uniformly mixing, slowly adding 1.32ml of tetrabutyl titanate under continuous stirring, adding 0.96g of sodium hydroxide after complete dissolution, and stirring for 1 h. Transferring the obtained mixture into a 100ml high-pressure reaction kettle, reacting for 15h at 180 ℃, cooling, washing the obtained product with deionized water and absolute ethyl alcohol for three times, drying, grinding, dissolving 0.3g of sample into a mixed solvent of 15ml of ethylene glycol and 45ml of deionized water, stirring uniformly, adding 1.36g of EDTA-2Na, stirring uniformly, transferring the mixed solution into the 100ml high-pressure reaction kettle, reacting for 15h in a 180 ℃ oven, cooling to room temperature after the chelation reaction is finished, performing vacuum filtration washing with absolute ethyl alcohol and deionized water, drying the obtained sample in the oven, fully grinding, transferring into a muffle furnace, heating to 400 ℃ at a heating rate of 5 ℃/min, and keeping for 2h to obtain TiO₂-15 composite nano-photocatalyst.

Example 2

Dissolving 0.44g of calcium chloride dihydrate in a mixed solvent of 15ml of polyethylene glycol-200 and 45ml of absolute ethyl alcohol, uniformly mixing, and stirring continuously according to the weight ratio of titanium: the lanthanum molar ratio is 20: 0.0840g of lanthanum nitrate is added to the above mixed solution and stirred uniformly, then 1.32ml of tetrabutyl titanate is slowly added and dissolved completely, and 0.96g of sodium hydroxide is added and stirred for 1 h. Transferring the obtained mixture into a 100ml high-pressure reaction kettle, reacting for 15h at 180 ℃, cooling, washing the obtained product with deionized water and absolute ethyl alcohol for three times, drying, grinding, dissolving 0.3g of sample into a mixed solvent of 15ml of ethylene glycol and 45ml of deionized water, stirring uniformly, adding 1.36g of EDTA-2Na, stirring uniformly, transferring the mixed solution into the 100ml high-pressure reaction kettle, reacting for 15h in a 180 ℃ oven, cooling to room temperature after the chelation reaction is finished, performing vacuum filtration washing with absolute ethyl alcohol and deionized water, drying the obtained sample in the oven, fully grinding, transferring into a muffle furnace, heating to 400 ℃ at a heating rate of 5 ℃/min, and keeping for 2h to obtain the La-TiO₂-15 composite nano-photocatalyst.

Example 3

Dissolving 0.44g of calcium chloride dihydrate in a mixed solvent of 15ml of polyethylene glycol-200 and 45ml of absolute ethyl alcohol, uniformly mixing, and stirring continuously according to the weight ratio of titanium: the molar ratio of cerium is 20: 1, adding 0.0842g of cerium nitrate into the mixed solution, uniformly stirring, then slowly adding 1.32ml of tetrabutyl titanate, completely dissolving, adding 0.96g of sodium hydroxide, and stirring for 1 hour. Transferring the obtained mixture into a 100ml high-pressure reaction kettle, reacting for 15h at 180 ℃, cooling, washing the obtained product with deionized water and absolute ethyl alcohol for three times, drying, grinding, dissolving 0.3g of sample into a mixed solvent of 15ml of ethylene glycol and 45ml of deionized water, stirring uniformly, adding 1.36g of EDTA-2Na, stirring uniformly, transferring the mixed solution into the 100ml high-pressure reaction kettle, reacting for 15h in a 180 ℃ oven, cooling to room temperature after the chelation reaction is finished, performing vacuum filtration washing with absolute ethyl alcohol and deionized water, drying the obtained sample in the oven, fully grinding, transferring into a muffle furnace, heating to 400 ℃ at a heating rate of 5 ℃/min, and keeping for 2h to obtain the Ce-TiO₂-15 composite nano-photocatalyst.

Example 4

Dissolving 0.44g of calcium chloride dihydrate in a mixed solvent of 15ml of polyethylene glycol-200 and 45ml of absolute ethyl alcohol, uniformly mixing, and stirring continuously according to the weight ratio of titanium: the samarium mol ratio is 20: 0.0845g of samarium nitrate is added to the mixed solution and stirred uniformly, then 1.32ml of tetrabutyl titanate is slowly added and dissolved completely, and 0.96g of sodium hydroxide is added and stirred for 1 h. Transferring the obtained mixture into a 100ml high-pressure reaction kettle, reacting for 15h at 180 ℃, cooling, washing the obtained product with deionized water and absolute ethyl alcohol for three times, drying, grinding, dissolving 0.3g of sample into a mixed solvent of 15ml of ethylene glycol and 45ml of deionized water, stirring uniformly, adding 1.36g of EDTA-2Na, stirring uniformly, transferring the mixed solution into the 100ml high-pressure reaction kettle, reacting for 15h in a 180 ℃ oven, cooling to room temperature after the chelation reaction is finished, performing vacuum filtration washing with absolute ethyl alcohol and deionized water, drying the obtained sample in the oven, fully grinding, transferring into a muffle furnace, heating to 400 ℃ at a heating rate of 5 ℃/min, and keeping for 2h to obtain Sm-TiO₂-15 composite nano-photocatalyst.

Example 5

Dissolving 0.44g of calcium chloride dihydrate in a mixed solvent of 15ml of polyethylene glycol-200 and 45ml of absolute ethyl alcohol, uniformly mixing, and stirring continuously according to the weight ratio of titanium: the ytterbium molar ratio is 20: 0.0854g of ytterbium nitrate is added to the above mixed solution and stirred uniformly, then 1.32ml of tetrabutyl titanate is slowly added and dissolved completely, and 0.96g of sodium hydroxide is added and stirred for 1 h. Transferring the obtained mixture into a 100ml high-pressure reaction kettle, reacting for 15h at 180 ℃, cooling, washing the obtained product with deionized water and absolute ethyl alcohol for three times, drying, grinding, dissolving 0.3g of sample into a mixed solvent of 15ml of ethylene glycol and 45ml of deionized water, stirring uniformly, adding 1.36g of EDTA-2Na, stirring uniformly, transferring the mixed solution into the 100ml high-pressure reaction kettle, reacting for 15h in a 180 ℃ oven, cooling to room temperature after the chelation reaction is finished, performing vacuum filtration and washing with absolute ethyl alcohol and deionized water, drying the obtained sample in the oven, fully grinding, transferring into a muffle furnace, heating to 400 ℃ at a heating rate of 5 ℃/min, keeping for 2h, and obtaining Yb-TiO₂-15 compoundingA nano photocatalyst.

Example 6

Dissolving 0.44g of calcium chloride dihydrate in a mixed solvent of 15ml of polyethylene glycol-200 and 45ml of absolute ethyl alcohol, uniformly mixing, and stirring continuously according to the weight ratio of titanium: the thulium molar ratio is 20: 0.0846g of thulium nitrate is added into the mixed solution 1 and stirred evenly, then 1.32ml of tetrabutyl titanate is slowly added, and 0.96g of sodium hydroxide is added and stirred for 1 hour after complete dissolution. Transferring the obtained mixture into a 100ml high-pressure reaction kettle, reacting for 15h at 180 ℃, cooling, washing the obtained product with deionized water and absolute ethyl alcohol for three times, drying, grinding, dissolving 0.3g of sample into a mixed solvent of 15ml of ethylene glycol and 45ml of deionized water, stirring uniformly, adding 1.36g of EDTA-2Na, stirring uniformly, transferring the mixed solution into the 100ml high-pressure reaction kettle, reacting for 15h in a 180 ℃ oven, cooling to room temperature after the chelation reaction is finished, performing vacuum filtration washing with absolute ethyl alcohol and deionized water, drying the obtained sample in the oven, fully grinding, transferring into a muffle furnace, heating to 400 ℃ at a heating rate of 5 ℃/min, and keeping for 2h to obtain the Tm-TiO₂-15 composite nano-photocatalyst.

Pure TiO was prepared according to the methods of examples 1-6 above₂TiO doped with different rare earth elements₂Photocatalyst, T60S1 composite photocatalyst with different copper deposition amounts. FIG. 1 shows pure TiO2 and different rare earth doped TiO prepared in examples 1-6₂The X-ray diffraction pattern of the photocatalyst can be seen from the XRD diffraction pattern in figure 1 that the diffraction peaks near 25.28 degrees, 37.80 degrees, 38.57 degrees, 48.05 degrees, 53.89 degrees, 55.06 degrees, 62.12 degrees, 70.31 degrees and 75.03 degrees respectively correspond to anatase TiO₂Diffraction peaks near 33.1 ℃ ascribed to brookite Ti₃O₅And meanwhile, no obvious diffraction peak of lanthanide metals is found in an XRD pattern, which may be caused by too low doping ratio. The characteristic peak at 25.28 degrees is amplified, and the characteristic peak of the (101) crystal plane is shifted, so that the lanthanide metal is further proved to be doped into the crystal lattice.

Tm-TiO prepared in example 1 and example 6₂The scanning electron microscope and the transmission electron microscope of the hollow box are shown in figures 2 and 3. ByAs can be seen in fig. 2 and 3, both the lanthanide metal-doped titanium dioxide and the pure titanium dioxide form hollow cubic boxes aggregated by particles, and the transmission electron microscope and high-resolution transmission electron microscope images more clearly show the hollow structure of the sample.

TiO doped with different prepared rare earth elements₂The hollow box is used for catalyzing and degrading pirimicarb, triadimefon, pyrazofos and deltamethrin and is carried out according to the following steps: respectively weighing 50mg of TiO doped with different rare earth elements₂Hollow box and TiO doped with rare earth elements₂Putting the hollow box into a 250mL beaker to form six groups of parallel tests, respectively adding mixed solutions (20 mg/L) of pirimicarb, triadimefon, pyrazothion and deltamethrin, and performing photocatalytic degradation reaction by using a 250W metal halide lamp (Shanghai Mingming lamp house) as a light source. Dark reaction time is 30min, and samples are taken every 20min after illumination. Centrifuging at 10000rpm, collecting supernatant, filtering with 0.22 μm filter membrane, and measuring concentration change with liquid chromatography-mass spectrometer.

As can be seen from FIG. 4, the thulium-doped TiO prepared in example 6 was obtained within 180min₂The effect of the hollow box for degrading the mixed pesticide is optimal, and the four pesticides are almost completely degraded. All samples have better degradation effect on four types of pesticides, which is probably due to the fact that the hollow box structure has larger specific surface area and Tm-TiO₂Has the best activity because of the Tm-doped TiO₂More surface oxygen vacancies, faster electron hole transport rate and stronger light absorption capacity.