阅读说明：本技术 一种黑磷量子点/纳米片复合材料及其制备方法 (Black phosphorus quantum dot/nanosheet composite material and preparation method thereof ) 是由 韩斌 席婷 楚阳阳 许并社 马淑芳 郝晓东 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种黑磷量子点/纳米片复合材料及其制备方法,属于复合材料制备技术领域,包括以下步骤：S1：制备黑磷分散液；S2：将S1黑磷分散液分别经过第一步微波处理和第二步微波处理,制得混合物；S3：将S2混合物进行离心处理,制得黑磷纳米片分散液；S4：将S3黑磷纳米片分散液进行微波处理,制得黑磷量子点/纳米片复合材料；本发明相比于超声处理,具有非常短的处理时间,不需要使用任何表面活性剂或超声来获得稳定少层黑磷；当微波辐照作用于试样时,黑磷大块薄片之间的范德华相互作用开始减弱,在合适的溶剂中逐层剥落,有效实现了黑磷量子点生长在片上的结构。(The invention discloses a black phosphorus quantum dot/nanosheet composite material and a preparation method thereof, belonging to the technical field of composite material preparation and comprising the following steps: s1: preparing a black phosphorus dispersion liquid; s2: respectively carrying out first-step microwave treatment and second-step microwave treatment on the S1 black phosphorus dispersion liquid to prepare a mixture; s3: centrifuging the S2 mixture to obtain a black phosphorus nanosheet dispersion liquid; s4: carrying out microwave treatment on the S3 black phosphorus nanosheet dispersion liquid to prepare a black phosphorus quantum dot/nanosheet composite material; compared with ultrasonic treatment, the method has very short treatment time, and does not need any surfactant or ultrasound to obtain stable few-layer black phosphorus; when microwave irradiation acts on a sample, Van der Waals interaction between the black phosphorus bulk thin slices begins to weaken, and the black phosphorus bulk thin slices are peeled off layer by layer in a proper solvent, so that the structure that the black phosphorus quantum dots grow on the slices is effectively realized.)

1. A preparation method of a black phosphorus quantum dot/nanosheet composite material is characterized by comprising the following steps:

s1: preparing a black phosphorus dispersion liquid;

s2: respectively carrying out first-step microwave treatment and second-step microwave treatment on the S1 black phosphorus dispersion liquid to prepare a mixture;

the microwave treatment conditions of the first step are as follows: the microwave temperature is 45-55 ℃, the microwave power is 550-650W, and the time is 15-25 min; the second microwave treatment condition is as follows: the microwave temperature is 65-75 ℃, the microwave power is 180-220W, and the time is 2-5 min;

s3: centrifuging the S2 mixture, and taking the upper layer liquid to obtain a black phosphorus nanosheet dispersion liquid;

s4: and (3) carrying out microwave treatment on the S3 black phosphorus nanosheet dispersion liquid for 5-15 min at the temperature of 115-125 ℃ and the microwave power of 550-650W to obtain the black phosphorus quantum dot/nanosheet composite material.

2. The preparation method of the black phosphorus quantum dot/nanosheet composite material as claimed in claim 1, wherein the black phosphorus dispersion in S1 is specifically prepared by:

putting black phosphorus in a saturated NaOH/NMP solution, and uniformly stirring to prepare a black phosphorus dispersion liquid; black phosphorus: the dosage ratio of NaOH to NMP is 4-6 mg: 1 ml.

3. The preparation method of the black phosphorus quantum dot/nanosheet composite material according to claim 1, wherein the centrifuging condition in S3 is that the centrifuging speed is 5500-6500 rpm/min for 15-25 min, and then centrifuging is continued, and the centrifuging speed is 8500-9500 rpm/min for 15-25 min.

4. The black phosphorus quantum dot/nanosheet composite material prepared by the preparation method according to any one of claims 1 to 3.

Technical Field

The invention belongs to the technical field of composite material preparation, and particularly relates to a black phosphorus quantum dot/nanosheet composite material and a preparation method thereof.

Background

Black Phosphorus (BP), which is very graphite-like in appearance, performance and structure, appears black, flaky, and is electrically conductive, with the linking atoms appearing as wrinkled sheets. Phonons, photons and electronic electrons in the layered black phosphorus structure show high anisotropy, and have great potential application value in electronic thin film and infrared photoelectronic technology. Light absorption in black phosphor is very sensitive to light polarization, film thickness and doping. Black phosphorus phototransistors also exhibit hyperspectral detection in infrared and visible light. Black phosphorus also includes the possibility of exfoliation, forming phosphenes, a graphite-like material with excellent electron transfer properties, similar to graphite.

The method for obtaining high-quality two-dimensional black phosphorus is the most critical preparation link, the research idea is similar to the preparation of graphene with a similar structure, the main research is concentrated in nearly two years, so the preparation of the two-dimensional black phosphorus is still in the preliminary stage of research, and the industrialization needs a current day. The current methods for preparing two-dimensional black phosphorus mainly comprise three methods: mechanical lift-off, liquid phase lift-off, pulsed laser deposition.

In the liquid phase stripping method, ultrasonic treatment is the most commonly used, but the ultrasonic treatment needs a longer time, the transverse dimension can be reduced along with the lengthening of the ultrasonic time, and abnormal structural defects are caused in the two-dimensional nano-sheet, and the two-dimensional nano-sheet obtained by the method, and the composite material of the black phosphorus quantum dot and the nano-sheet is not reported.

Disclosure of Invention

The invention aims to provide a black phosphorus quantum dot/nanosheet composite material and a preparation method thereof, aiming at the defects in the prior art.

The first purpose of the invention is to provide a preparation method of a black phosphorus quantum dot/nanosheet composite material, which comprises the following steps:

s1: preparing a black phosphorus dispersion liquid;

s2: respectively carrying out first-step microwave treatment and second-step microwave treatment on the S1 black phosphorus dispersion liquid to prepare a mixture;

the microwave treatment conditions of the first step are as follows: the microwave temperature is 45-55 ℃, the microwave power is 550-650W, and the time is 15-25 min; the second microwave treatment condition is as follows: the microwave temperature is 65-75 ℃, the microwave power is 180-220W, and the time is 2-5 min;

s3: centrifuging the S2 mixture, and taking the upper layer liquid to obtain a black phosphorus nanosheet dispersion liquid;

s4: and (3) carrying out microwave treatment on the S3 black phosphorus nanosheet dispersion liquid for 5-15 min at the temperature of 115-125 ℃ and the microwave power of 550-650W to obtain the black phosphorus quantum dot/nanosheet composite material.

Preferably, the black phosphorus dispersion liquid in S1 is prepared by the following steps:

putting black phosphorus in a saturated NaOH/NMP (N-methyl pyrrolidone) solution, and uniformly stirring to prepare a black phosphorus dispersion liquid; black phosphorus: the dosage ratio of NaOH to NMP is 4-6 mg: 1 ml.

Preferably, the centrifugation treatment in S3 is carried out at a centrifugation speed of 5500-6500 rpm for 15-25 min, and then the centrifugation is continued at 8500-9500 rpm for 15-25 min.

The second purpose of the invention is to provide the black phosphorus quantum dot/nanosheet composite material prepared by the preparation method.

Compared with the prior art, the invention has the following beneficial effects:

the method adopts a two-step microwave method, firstly uses high-power microwave to treat blocky black phosphorus dispersion liquid to destroy van der Waals force between black phosphorus layers, then uses low-power microwave to treat the blocky black phosphorus to further separate the blocky black phosphorus into few layers of black phosphorus sheets, and obtains the black phosphorus nano sheets with required size through centrifugal treatment and separation; the centrifuged black phosphorus nanosheets are subjected to one-step microwave treatment, so that the fragmentation effect of the nanosheets is effectively realized, and the compounding of the nanosheets and the quantum dots is realized; compared with ultrasonic treatment, the method has very short treatment time, and does not need any surfactant or ultrasound to obtain stable and few-layer black phosphorus; when microwave irradiation acts on a sample, Van der Waals interaction between the black phosphorus bulk thin slices begins to weaken, and the black phosphorus bulk thin slices are peeled off layer by layer in a proper solvent, so that the structure that the black phosphorus quantum dots grow on the slices is effectively realized.

Drawings

FIG. 1 is a transmission diagram of a black phosphorus quantum dot/nanosheet composite prepared in example 1;

FIG. 2 is an electron diffraction pattern of the region shown in FIG. 1;

fig. 3 is a transmission diagram of a local area of the black phosphorus quantum dot/nanosheet composite prepared in example 1.

Detailed Description

In order to make the technical solutions of the present invention better understood and implemented by those skilled in the art, the present invention is further described below with reference to the following specific embodiments and the accompanying drawings, but the embodiments are not meant to limit the present invention.