阅读说明：本技术 一种二维黑磷表面保护方法 (Two-dimensional black phosphorus surface protection method ) 是由 乔海石 黄鑫 陈维 于 2020-08-12 设计创作，主要内容包括：本发明公开了一种二维黑磷表面保护方法,其特征在于：包括如下步骤：(1)取4-二甲氨基吡啶(DMAP)、可发生亲核取代的化合物和黑磷,常温下在有机溶剂和水的混合液中反应；(2)上述反应完成后,去除未反应的可发生亲核取代的化合物；(3)将反应后的分散液离心分离得到保护的黑磷(BP-可发生亲核取代的化合物)。本发明方法利用含有羧基官能团的化合物与黑磷表面自身氧化形成的羟基反应得到共价保护的黑磷,所得共价保护的黑磷稳定性好。(The invention discloses a two-dimensional black phosphorus surface protection method, which is characterized by comprising the following steps: the method comprises the following steps: (1) 4-dimethylamino pyridine (DMAP), a compound capable of undergoing nucleophilic substitution and black phosphorus are taken to react in a mixed solution of an organic solvent and water at normal temperature; (2) after the reaction is completed, removing unreacted compound capable of nucleophilic substitution; (3) the dispersion after the reaction was centrifuged to obtain protected black phosphorus (BP-a compound capable of undergoing nucleophilic substitution). The method of the invention utilizes the reaction of the compound containing carboxyl functional groups and hydroxyl formed by the self-oxidation of the surface of the black phosphorus to obtain the black phosphorus with covalent protection, and the obtained black phosphorus with covalent protection has good stability.)

1. A two-dimensional black phosphorus surface protection method is characterized by comprising the following steps: the method comprises the following steps:

(1) 4-dimethylamino pyridine (DMAP), a compound capable of undergoing nucleophilic substitution and black phosphorus are taken to react in a mixed solution of an organic solvent and water at normal temperature;

(2) after the reaction is completed, removing unreacted compound capable of nucleophilic substitution;

(3) the dispersion after the reaction was centrifuged to obtain protected black phosphorus (BP-a compound capable of undergoing nucleophilic substitution).

2. The two-dimensional black phosphorus surface protection method according to claim 1, wherein: the compound which can be subjected to nucleophilic substitution in the step (1) is arginine, lysine or proline.

3. The two-dimensional black phosphorus surface protection method according to claim 1, wherein: the organic solvent in the step (1) is N, N' -Dimethylformamide (DMF) or dimethyl sulfoxide.

4. The two-dimensional black phosphorus surface protection method according to claim 1, wherein: in the step (2), unreacted nucleophilic substitution-allowed compound is removed by using a dialysis bag.

Technical Field

The invention relates to a preparation method of a two-dimensional material, in particular to a two-dimensional black phosphorus surface protection method.

Background

The Black Phosphorus (BP) can be used as a good photo-thermal reagent due to the characteristics of wide absorption from ultraviolet to near infrared, large near infrared extinction coefficient, high photo-thermal conversion efficiency and the like; the special folding structure on the surface enables the medicine carrier to have larger specific surface area and higher medicine carrying performance; and phosphorus is one of important elements of the human body and can be irreversibly degraded into non-toxic phosphates and phosphonates, thereby showing good biocompatibility. However, the degradability of black phosphorus has severely hampered its development in basic research and potential practical applications. The black phosphorus can react with water and oxygen in the air to cause the change of components and the like until the components are completely degraded, so that the electronic and optical properties are obviously reduced, and the application of the black phosphorus in the fields of electrocatalysis and biomedicine is further limited. Therefore, an effective protection of black phosphorus is an effective strategy for improving the environmental stability of black phosphorus, and at present, three main methods of coating, doping, bonding and the like are mainly available.

Most of the coating methods use high molecular materials to coat black phosphorus in a cavity by utilizing electrostatic interaction so as to achieve the effect of isolating water and oxygen, but the strategy cannot fundamentally solve the problem of instability of the black phosphorus, and the black phosphorus can still be gradually oxidized and degraded from the edge after being exposed to the environmental conditions for a certain time. The doping method is a method for improving stability by doping other atoms in black phosphorus, but at present, the doping conditions are relatively harsh, the doping technology is relatively complex and high in cost, and the method is not suitable for large-scale application. Compared with the former two methods, the bonding method introduces some specific groups which can occupy lone pair electrons on the surface of a phosphorus atom, thereby fundamentally preventing the reaction of phosphorus and oxygen and having better stability effect. Zhao et al (angel. chem. int. ed., 2016, 55 (16): 5003-5007.) use a titanium sulfonate (TiL4) ligand to occupy lone pair electrons on the surface of black phosphorus by means of coordination bonds to form a stable complex. Ryder et al (Nature chem., 2016, 8 (6): 597-602.) modify black phosphorus with diazobenzene compounds, which can occupy lone pairs of electrons on the surface of black phosphorus and spontaneously form P-C bonds. However, the development and application of small molecules or heavy metal ions introduced by the existing bond-forming protection method in the field of biological medicine can be seriously influenced. Therefore, the selection of compounds with good biocompatibility is a potential alternative.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a two-dimensional black phosphorus surface protection method.

Arginine, lysine and other amino acids containing active amino groups react with hydroxyl groups formed by primary oxidation on the surface of the black phosphorus to be covalently connected with the amino acids so as to prevent the further oxidation of the black phosphorus, and the covalent conjugate has high biocompatibility, improves the stability of the black phosphorus and does not influence the photo-thermal performance of the black phosphorus.

The technical scheme is as follows: the invention provides a two-dimensional black phosphorus surface protection method, which comprises the following steps:

(1) 4-dimethylamino pyridine (DMAP), a compound capable of undergoing nucleophilic substitution and black phosphorus are taken to react in a mixed solution of an organic solvent and water at normal temperature;

(2) after the reaction is completed, removing unreacted compound capable of nucleophilic substitution;

(3) and centrifugally separating the reacted dispersion to obtain the protected black phosphorus (BP-compound capable of nucleophilic substitution), wherein the molecular structural formula of the protected black phosphorus is as follows:

further, the compound in which nucleophilic substitution may occur in the step (1) is arginine (Arg), lysine or proline.

Further, the organic solvent in the step (1) is N, N' -Dimethylformamide (DMF) or dimethyl sulfoxide.

Further, in the step (2), unreacted nucleophilic substitution-allowed compound is removed by a dialysis bag.

Has the advantages that: the product of the invention is a two-dimensional black phosphorus material which can be covalently protected by a compound capable of undergoing nucleophilic substitution, such as arginine, lysine or proline. The two-dimensional black phosphorus is successfully protected by using active carboxyl compounds such as arginine and the like with good biocompatibility, the preparation process is simple, the reaction condition is mild, the product is easy to purify, the photo-thermal property of the black phosphorus is reserved, and the development and application of the black phosphorus in the field of biological medicines are expanded.

Drawings

FIG. 1 is a UV spectrum of two-dimensional black phosphorus;

FIG. 2 is a BP-Arg UV map;

FIG. 3 is a BP-Arg infrared spectrum;

FIG. 4 is a two-dimensional black phosphorus TEM image;

FIG. 5 is a TEM map of BP-Arg;

FIG. 6 is a two-dimensional black phosphorus particle size spectrum;

FIG. 7 is a BP-Arg particle size map;

FIG. 8 is a potential map of two-dimensional black phosphorus and BP-Arg;

FIG. 9 is a BP-Arg particle size stability map.

Detailed Description

Definition of Compounds in Table 1

DMAP	4-dimethylaminopyridine
		Arg	Arginine
DMF	NN' -dimethylformamide