AU2020103064A4

AU2020103064A4 - Phosphorene/graphene three-dimensional aerogel material and preparation method and application thereof

Info

Publication number: AU2020103064A4
Application number: AU2020103064A
Authority: AU
Inventors: Xiaohong CAO; Ying DAI; Yuhui Liu; Yunhai LIU; Yingcai Wang; Zhibin Zhang
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2020-04-01
Filing date: 2020-10-28
Publication date: 2020-12-24
Anticipated expiration: 2028-10-28
Also published as: CN111422840A; CN111422840B

Abstract

ADstracy The present invention discloses a phosphorene/graphene three-dimensional aerogel material and a preparation method and application thereof. Graphene is prepared by a Hermes method. Black phosphorus is prepared by a mineralization method. Phosphorene is prepared by a liquid phase intercalation method. A certain amount of graphene and phosphorene is uniformly dispersed in deionized water, ultrasonically stirred for a period of time and finally dried by freezing, and the phosphorene and the graphene are self-assembled to form the phosphorene/graphene three-dimensional aerogel material by forming C-O-P bonds and C-P bonds. The phosphorene is used for the treatment of uranium-containing radioactive waste water. The phosphorene/graphene three-dimensional aerogel material effectively reduces the environmental degradation of the phosphorene, improves the stability of the phosphorene in the process of adsorbing and separating uranyl ions in the radioactive waste water, increases the overall uranium adsorption capacity of the material, and has extremely high selectivity for the adsorption of uranium. The preparation process is simple and controllable, and the practical application value is high. 1 Drawings of Description C IaiI2 O05l PKa Fig. 1 Zid 409-2 28d 200 too 0 100 210 300 400 2000 40000 i (min) Fig. 2 1

Description

ADstracy

The present invention discloses a phosphorene/graphene three-dimensional aerogel material

and a preparation method and application thereof. Graphene is prepared by a Hermes method.

Black phosphorus is prepared by a mineralization method. Phosphorene is prepared by a liquid

phase intercalation method. A certain amount of graphene and phosphorene is uniformly dispersed

in deionized water, ultrasonically stirred for a period of time and finally dried by freezing, and the

phosphorene and the graphene are self-assembled to form the phosphorene/graphene

three-dimensional aerogel material by forming C-O-P bonds and C-P bonds. The phosphorene is

used for the treatment of uranium-containing radioactive waste water. The phosphorene/graphene

three-dimensional aerogel material effectively reduces the environmental degradation of the

phosphorene, improves the stability of the phosphorene in the process of adsorbing and separating

uranyl ions in the radioactive waste water, increases the overall uranium adsorption capacity of the

material, and has extremely high selectivity for the adsorption of uranium. The preparation process

is simple and controllable, and the practical application value is high.

Drawings of Description

C IaiI2 O05l PKa

Fig. 1

Zid 409-2 28d

200

too

0 100 210 300 400 2000 40000 i (min)

Fig. 2

Description

PHOSPHORENE/GRAPHENE THREE-DIMENSIONAL AEROGEL MATERIAL AND PREPARATION METHOD AND APPLICATION THEREOF

Technical Field

The present invention relates to the technical field of composite materials, and more

particularly relates to a phosphorene/graphene three-dimensional aerogel material and a

preparation method and application thereof.

Background

Uranium is a radioactive element and the main fuel for nuclear power. Thus, to ensure its

safe and efficient use is a main requirement at present. A large amount of uranium-containing

radioactive waste water may be generated in the nuclear fuel circulation process such as uranium

mining, nuclear fuel processing and spent fuel treatment and disposal. The uranium and decay

progenies such as 22 6Ra, 222 Rn and 2 10 Po contained in the waste water have both chemical

toxicity and radioactive toxicity. A large amount of accumulation in the environment poses a

potential threat to the survival of human beings and the development of environmental protection.

Therefore, the treatment of radioactive pollution is one of the most challenging problems at

present. Whether to increase the utilization rate of the uranium resource or to reduce the harm of

the radioactive waste water on the environment by recycling the uranium from the

uranium-containing waste water, the uranium in the water solution needs to be separated and

concentrated. Compared with the conventional uranium separation and concentration methods

such as chemical precipitation, ion exchange, solvent extraction, filtration and reverse osmosis,

the adsorption method has the advantages of wide material sources, low cost, high selectivity,

high speed and large capacity, thereby becoming the most effective and most common method

for separating and concentrating the uranium from the environment.

Phosphorene is a single-layer or few-layer black phosphorus. It is a novel two-dimensional

material with a structure similar to graphene. Six P atoms are encircled to form a cyclic

Description

hexagonal structure. Due to the effect of SP3 hybridization, P atoms form a wrinkled surface

structure. Phosphorene is another two-dimensional semiconductor material after graphene and

transition metal sulfides, which has a promising prospect. Phosphorene has a great application

prospect in the fields of transistors, sensors, solar cells and electrode cells. However, it also has a

fatal problem. When exposed in the environment, the phosphorene is prone to oxidative

degradation. That is, under a light condition, 02 in the environment forms oxygen anions on the

surface of the phosphorene to be accumulated on edges or defective parts, the oxygen anions are

then bonded with P atoms on the surface of the phosphorene, and finally under the action of

water molecules, P-O is separated from the surface of the phosphorene to form phosphoric acid,

which causes the breaking of P-P bonds on the surface of the phosphorene. P at the fracture is

likely to bond with oxygen to form P-0, P-O is also likely to bond with other P to form P-0-P,

and P is also likely to continuously leave the surface of the phosphorene under the action of the

water molecules, so that its stability is very poor. The oxygen in P-0 and P=O in the phosphoric

acid group is easy to complex with uranyl ions, and the phosphoric acid group is often modified

on the surface of various solid substrates to adsorb and separate the uranyl ions in the radioactive

waste water. Thus, it can be seen that the surface of the phosphorene is rich in P-O groups,

thereby having good selective adsorption capacity for the uranyl ions.

Therefore, how to improve the stability of the phosphorene in the environment and to apply

the phosphorene to the treatment of the uranium waste water is a problem to be urgently solved

by those skilled in the art.

Summary

In view of this, the present invention provides a phosphorene/graphene three-dimensional

aerogel material and a preparation method and application thereof. Graphene is compounded

with phosphorene, so that the environmental stability of the phosphorene can be effectively

improved, and when the phosphorene is applied to the separation and concentration of uranium,

the effect is good.

To realize the above purpose, the present invention adopts the following technical

Description

solutions:

The preparation method of the phosphorene/graphene three-dimensional aerogel material

includes the following steps:

(1) mixing red phosphorus, tin powder, and tin iodide into an ampoule bottle, vacuumizing

until the pressure is less than 0.05 Pa, sealing a tube, heating a raw material end in the ampoule

bottle to 200°C, then heating up to 600°C, keeping the temperature at 600°C for 6h, then cooling

to 300°C, keeping the temperature at 300°C for 2 days, and finally cooling to the room

temperature, to obtain a black product (black phosphorus);

(2) weighing the black phosphorus obtained in the step (1) into a test tube, dropwise

adding N-methyl-2-pyrazolone, ultrasonically mixing for 24 h at 40 kHz, controlling the

ultrasonic temperature to be less than or equal to 30°C, centrifuging to obtain bottom black

solids, and freeze drying to obtain phosphorene;

(3) dispersing graphene oxide in deionized water to form a graphene aqueous solution;

dispersing the phosphorene obtained in step (2) into the deionized water to form a phosphorene

aqueous solution, mixing the two solutions, stirring for 3 h, then ultrasonically mixing for 3 h at

kHz at 30°C, repeatedly ultrasonically mixing for three times, and freeze drying to obtain the

phosphorene/graphene three-dimensional aerogel material.

Preferably, a mass ratio of red phosphorus to tin powder to tin iodide in the step (1) is

:2:1.

Preferably, in the step (1), the temperature increases to 600°C in 1 h, and decreases to

300°C in 6 h, and after the temperature preservation at 300°C is finished, the temperature is

lowered to the room temperature in 1Oh.

The principle of the above preferred technical solution is that: tin iodide and red

phosphorus are completely sublimated to the top of the ampoule bottle at 600°C, and due to the

excessive amount of tin, tin iodide may not be decomposed; thereafter, in a cooling phase, tin

iodide is first condensed and deposited on the bottom of the ampoule bottle to become a

nucleation site of P; and at the temperature about 300°C, P gas begins to grow at the nucleation

site on the bottom, and the growth of black phosphorus crystals lasts for about 10 h.

Description

Preferably, in the step (2), a ratio of the black phosphorus to N-methyl -2- pyrazolone is 1

mg/mL.

The above preferred technical solution has the beneficial effects: the phosphorene of the

present solution utilizes a liquid-phase stripping method; N-methyl-2-pyrazolone is used to strip

the black phosphorus; when the ratio of black phosphorus (g) to N-methyl-2-pyrazolone(mL) is

:1, the phosphorene begins to be stripped; when the ratio of the black phosphorus to

N-methyl-2-pyrazolone is reduced, the stripping effect and the stripping time may be better;

however, if the ratio is too small, the stripped sheets may be too small, which is not conductive

to the protection.

A preparation method of the graphene oxide in the step (3) includes the following steps:

(3.1) weighing graphite, adding a certain amount of mixture of concentrated sulfuric acid

and concentrated nitric acid in a volume ratio of 3:1, fully dispersing the graphite to form

graphite dispersion of 2.5 mg/mL mixed solution, stirring for 24h, vacuum filtering, and drying

to obtain a graphene intercalation compound;

(3.2) heating the graphene intercalation compound obtained in the step (3.1) for 10s at

1000C to make it expand thermally, thereby obtaining expanded graphite;

(3.3) adding concentrated sulfuric acid, K 2 S 2 0 8 and P 2 0 5 into the expanded graphite

powder obtained in the step (3.2), stirring at 80°C, heating for 5 h, vacuum filtering, and drying

to obtain pre-oxidized expanded graphite;

(3.4) adding the pre-oxidized graphite obtained in the step (3.3) into the concentrated

sulfuric acid under an icy water bath condition, then adding KMnO4, heating and stirring for 2 h

at 35°C, then diluting, adding 30% H 2 0 2 , standing, pouring out supernatant, washing and

purifying with distilled water and hydrochloric acid solution, and drying to obtain the graphene

oxide.

Preferably, in the step (3.3), the addition amount of the concentrated sulfuric acid at 35°C

is 60 mL/g graphite, and a weight ratio of graphite to K2S20s to P 2 05 is 25:21:31.

Preferably, in the step (3.4), the addition amount of the concentrated sulfuric acid is

mL/g graphite, a weight ratio of graphite to KMnO4 is 1:3 , and an addition amount of 30%

Description

H20 2 is 2 mL/g graphite.

Preferably, the concentration of the graphene aqueous solution in the step (3) is 0.1-10

mg/mL, and the concentration of the phosphorene aqueous solution is 1-5 mg/mL.

The above preferred technical solution has the beneficial effect: the phosphorene aqueous

solution is prone to excessive oxidization if its concentration is too small and is easy to

precipitate if the concentration is too large.

Preferably, a volume ratio of the graphene aqueous solution to the phosphorene aqueous

solution is (1: 100)-(100:1).

The above preferred technical solution has the beneficial effect: through the adsorption

experiment, the smaller the ratio of graphene to phosphorene is (the more the phosphorene is),

the better the adsorption performance is; however, when the mass percentage of the phosphorene

is greater than 20%, the film forming effect is poor, and the graphene cannot well protect the

phosphorene.

The present invention also provides a phosphorene/graphene three-dimensional aerogel

material prepared by the above technical solutions.

Furthermore, the present invention also provides an application of the aforementioned

phosphorene/graphene three-dimensional aerogel material in the treatment of

uranium-containing waste water.

Preferably, the pH of the uranium-containing waste water is 3.0-5.5, the uranium

concentration is 20-130 mg/L, and the treatment time is 130-180 min.

It can be known from the above technical solutions that compared with the prior art, the

phosphorene/graphene three-dimensional aerogel material and the preparation method and

application thereof provided by the present invention have the following advantages:

The phosphorene is applied to the treatment of the uranium-containing radioactive waste

water, and the two two-dimensional materials, i.e. phosphorene and graphene are self-assembled

to prepare the phosphorene/graphene three-dimensional aerogel material by forming C-O-P

bonds and C-P bonds, so that the environmental degradation of the phosphorene can be

effectively reduced, and the stability of the phosphorene in the process of adsorbing and

Description

separating the uranyl ions in the radioactive waste water can be improved; moreover, by

compounding the phosphorene/graphene material, the overall uranium adsorption capacity of the

material can be effectively increased; and by limiting the treatment condition, the

phosphorene/graphene composite two-dimensional material has strong selectivity for the

adsorption of the uranium. The preparation process is simple and controllable, and the practical

application value is very high.

Description of Drawings

To more clearly describe the technical solutions in the embodiments of the present

invention or in the prior art, the drawings required to be used in the description of the

embodiments or in the prior art will be simply presented below. Apparently, the following

drawings only show some embodiments of the present invention, so for those ordinary skilled in

the art, other drawings can also be obtained according to the provided drawings without

contributing creative labor.

Fig. 1 shows SEM and Mapping images of a phosphorene/graphene three-dimensional

aerogel material;

Fig. 2 is a diagram showing the stability of the phosphorene/graphene three-dimensional

aerogel material;

Fig. 3 is a diagram showing an impact of the adsorption time on the uranium adsorption of

the phosphorene/graphene three-dimensional aerogel material when an initial concentration of

the uranium is 50 mg/L and pH is 5.5;

Fig. 4 is a diagram showing the impact of the uranium concentration on the uranium

adsorption of the phosphorene/graphene three-dimensional aerogel material when pH is 5.5;

Fig. 5 is a diagram showing the impact of pH on the uranium adsorption of the material;

Fig. 6 is a diagram showing selective adsorption capacity of the material under different

pH;

Fig. 7 is a diagram showing selectivity of the material under different pH; and

Fig. 8 is a diagram showing the selective adsorption performance of the

Description

phosphorene/graphene three-dimensional aerogel material for the uranium when pH is 3.0.

Detailed Description

Technical solutions in embodiments of the present invention are clearly and completely

described in combination with accompanying drawings in embodiments of the present invention.

Apparently, the described embodiments are merely some embodiments of the present invention,

not all embodiments. Based on embodiments of the present invention, all other embodiments

obtained by those ordinary skilled in the art without contributing creative labor fall within the

protection scope of the present invention.

Embodiment

Step I. Preparation of graphene oxide

(3.1) 5 g graphite is weighed and added into a mixed solution with 150 mL concentrated

sulfuric acid and 50 mL concentrated nitric acid, stirred for 24 h, then vacuum filtered and

finally dried to obtain a graphene intercalation compound (GICs);

(3.2) The dried GICs powder is heated for 10 s at 100 0 °C to make it expand thermally,

thereby obtaining expanded graphite (EG);

(3.3) 300 mL concentrated sulfuric acid, 4.2 g K 2 S 2 0 8 and 6.2 g P 2 0 5 are added into the

EG powder, stirred at 80°C, heated for 5 h, then vacuum filtered, and dried to obtain

pre-oxidized EG;

(3.4) Under an icy bath condition, 200 mL concentrated sulfuric acid is added into the

pre-oxidized EG, then 15 g KMnO4 is added, the mixture is heated and stirred for 2 h at 35°C

and diluted, then 10 mL 30% H 2 0 2 is added, the mixture stands for a period of time, supernatant

is poured out, and precipitates are washed and purified with distilled water and hydrochloric acid

solution and dried to obtain the graphene oxide.

Step II. Preparation of a phosphorene/graphene three-dimensional aerogel material

(1) Red phosphorus (500 mg, 99.999%), tin powder (20 mg, 99.999%) and tin iodide (10

mg, 99%) are mixed and loaded into a quartz ampoule bottle, and vacuumized until the pressure

is less than 0.05 Pa, and then the tube is sealed; and a raw material end in the ampoule bottle is

Description

heated to 200°C, heated up to 600 0C in 1 h, kept at 600 0C for 6 h, then cooled to 300 0 C in 6 h, and kept at 300°C for 2 days. Finally, the temperature decreases to the room temperature in 10 h,

and a black product, i.e. black phosphorus is obtained;

(2) 10 mg black phosphorus is weighed into a test tube; 10 mL N-methyl-2-pyrrolidone

(NMP) is dropwise added; an ultrasonic washing machine is used to perform ultrasonic treatment

for 24 h at 40 kHz; a circulating water apparatus is used to control the temperature not to be

greater than 30 0C during the ultrasonic treatment; and bottom black solids are obtained by

centrifuging, and freeze dried to obtain phosphorene;

(3) The graphene oxide obtained in the step I is dispersed in the deionized water to form

2.5 mg/mL graphene aqueous solution; the phosphorene obtained in the step (2) is dispersed in

the deionized water to form 2.5 mg/mL phosphorene aqueous solution; the two solutions are

mixed in a volume ratio of 4:1, and the mixed solution is stirred for 3 h, subjected to 40 kHz

ultrasonic treatment for 3 h at 30°C, and repeatedly ultrasonically treated for three times; and

thereafter, the mixed solution is freeze dried until ice is completely sublimated, and residues are

the phosphorene/graphene three-dimensional aerogel material.

It can be known from Fig.1 that the phosphorene/graphene three-dimensional aerogel

material is prepared in the technical solutions of the present invention.

Test Example 1

I. Stability experiment of the phosphorene/graphene three-dimensional aerogel material

10 mg phosphorene/graphene three-dimensional aerogel material was weighed and placed

into an aqueous solution with pH of 5.5 to be subjected to sealing oscillation for 28 days; and an

ion chromatograph was used to determine the concentration of PO4 in the aqueous solution. As

shown in Fig. 2, after calculation, the mass of the phosphorene/graphene three-dimensional

aerogel material was reduced by 4% after being soaked in the aqueous solution with the pH of

5.5 for 28 days.

II. Static adsorption experiment

10 mg phosphorene/graphene three-dimensional aerogel material was accurately weighed

and placed into a 150 mL conical bottle, and then 50mL uranium solution with a fixed pH value

Description

(adjusted with a certain amount of HNO 3 or NaOH) and different initial concentrations at 25°C

was added and placed into a constant-temperature oscillation box for oscillation for a period of

time under 200 rpm, and supernatant was taken out to centrifuge. An ultraviolet

spectrophotometry was used to determine the uranium concentration in the solution, and results

were shown in Figs. 3-5. Under the pH of 5.5, the temperature of 25°C and the initial

concentration of the uranium solution of 50 mg/L, the adsorption of the uranium by the

phosphorene/graphene three-dimensional aerogel material reaches equilibrium at 120 min, and at

this moment, the adsorption capacity of the material for the uranium was 453 mg/g. Under the

pH of 5.5, the solution temperature of 25°C and the initial concentration of the uranium solution

of 120 mg/L, the adsorption of the uranium by the material was saturated, and at this moment,

the adsorption capacity for the uranium was 635 mg/g.

III. Selectivity adsorption experiment

and added into 25 mL co-existing ion mixed solution with a pre-determined pH value containing

U(VI), Ce(III), Cs(I), Gd(III), La(III), Sm(III), Co(II), Sr(II), Mn(II), Zn(II) and Ni(II). The

concentration of each ion was 0.5 mmol/L. After the constant-temperature oscillation for a

period of time, the mixed solution was centrifuged to collect supernatant. ICP-OES was used to

determine the concentration in the solution with results shown in Figs. 6-8. The total adsorption

amount qe(total) of metal ions and the adsorption amountqe(u) by the phosphorene/graphene

three-dimensional aerogel material were maximal at the pH of 5.0 and were 422 mg/g and 31

mg/g respectively. From the perspective of selectivity, it can be seen that the selectivity of the

phosphorene/graphene three-dimensional aerogel material for the uranium was maximal at pH of

3.0 and was 72%.

Each embodiment in the description is described in a progressive way. The difference of

each embodiment from each other is the focus of explanation. The same and similar parts among

all of the embodiments can be referred to each other. For the device disclosed by the

embodiments, because the device corresponds to a method disclosed by the embodiments, the

device is simply described. Refer to the description of the method part for the related part.

Description

The above description of the disclosed embodiments enables those skilled in the art to

realize or use the present invention. Many modifications made to these embodiments will be

apparent to those skilled in the art. General principles defined herein can be realized in other

embodiments without departing from the spirit or scope of the present invention. Therefore, the

present invention will not be limited to these embodiments shown herein, but will conform to the

widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A preparation method of phosphorene/graphene three-dimensional aerogel material,

comprising the following steps:

temperature, to obtain a black product (black phosphorus);

adding N-methyl-2-pyrazolone, ultrasonically mixing for 24 h, controlling the ultrasonic

temperature to be less than or equal to 30C, centrifuging to obtain bottom black solids, and

freeze drying to obtain phosphorene;

C, repeatedly ultrasonically mixing for three times, and freeze drying to obtain the

phosphorene/graphene three-dimensional aerogel material.

2. The preparation method of phosphorene/graphene three-dimensional aerogel material

according to claim 1, wherein a mass ratio of red phosphorus to tin powder to tin iodide in the

step (1) is 50:2:1.

3. The preparation method of phosphorene/graphene three-dimensional aerogel material

according to claim 1, wherein in the step (1), the temperature increases to 600°C in 1 h, and

decreases to 300°C in 6 h, and after the temperature preservation at 300°C is finished, the

temperature is lowered to the room temperature in 1Oh.

4. The preparation method of phosphorene/graphene three-dimensional aerogel material

according to claim 1, wherein in the step (2), a ratio of the black phosphorus to N-methyl -2

pyrazolone is 1 mg/mL.

5. The preparation method of phosphorene/graphene three-dimensional aerogel material

according to claim 1, wherein the concentration of the graphene aqueous solution in the step (3)

Claims

is 0.1-10 mg/mL, and the concentration of the phosphorene aqueous solution is 1-5 mg/mL.

6. The preparation method of phosphorene/graphene three-dimensional aerogel material

according to claim 1, wherein a volume ratio of the graphene aqueous solution to the

phosphorene aqueous solution is (1: 100)-(100:1).

7. A phosphorene/graphene three-dimensional aerogel material of any one of claims 1-6.

8. An application of the phosphorene/graphene three-dimensional aerogel material of

claim 7 in treatment of uranium-containing waste water.

9. The application of the phosphorene/graphene three-dimensional aerogel material

according to claim 8, wherein the pH of the uranium-containing waste water is 3.0-5.5, the

uranium concentration is 20-130 mg/L, and the treatment time is 130-180 min.