阅读说明：本技术 一种具有红色发光的黑磷氧化物材料的电化学制备方法 (Electrochemical preparation method of black phosphorus oxide material with red luminescence ) 是由 刘玉申 甘志星 于 2020-07-13 设计创作，主要内容包括：本发明公开了一种黑磷氧化物材料的制备方法,包括如下步骤：a,配制磷酸盐缓冲溶液作为电化学的电解液。b,将黑磷晶体原材料夹持在电化学工作站的工作电极上。c,进行电化学扫描,利用电化学反应对黑磷晶体进行氧化。d,对氧化后的样品进行结构和发光的表征,确保成果得到黑磷氧化物以及具备红光发光的特性。本发明首次公开了一种对黑磷晶体进行人工氧化的方法,实验方法简单、高效、成本低,制备得到的产物稳定,并且制备得到的黑磷氧化物具有波长在650纳米左右的发光,极大的拓展了黑磷相关结构和材料在光电器件领域潜在的应用。(The invention discloses a preparation method of a black phosphorus oxide material, which comprises the following steps: and a, preparing a phosphate buffer solution as an electrochemical electrolyte. And b, clamping the black phosphorus crystal raw material on a working electrode of the electrochemical workstation. And c, performing electrochemical scanning, and oxidizing the black phosphorus crystal by using an electrochemical reaction. And d, characterizing the structure and luminescence of the oxidized sample to ensure that the black phosphorus oxide is obtained and has the characteristic of red luminescence. The invention discloses a method for artificially oxidizing black phosphorus crystals for the first time, the experimental method is simple and efficient, the cost is low, the prepared product is stable, the prepared black phosphorus oxide has luminescence with the wavelength of about 650 nanometers, and the potential application of the black phosphorus related structure and material in the field of photoelectric devices is greatly expanded.)

1. An electrochemical preparation method of a black phosphorus oxide material with red luminescence is characterized by comprising the following steps:

a. preparing a phosphate buffer solution as an electrochemical electrolyte;

b. clamping the black phosphorus crystal raw material on a working electrode of an electrochemical workstation;

c. carrying out electrochemical scanning, and oxidizing the black phosphorus crystal by using electrochemical reaction;

d. carrying out structural and luminescence characterization on the oxidized sample;

the phosphate buffer solution in the step a is a phosphate buffer solution with a neutral pH value, and is prepared by mixing 0.1M potassium dihydrogen phosphate and 0.1M dipotassium hydrogen phosphate aqueous solution, wherein the mixture is fully stirred in the air in the preparation process, and the stirring time is not less than 1 h; injecting a proper amount of electrolyte into the electrolytic cell after the configuration is finished;

the electrochemical scanning in the step c is completed on a three-electrode electrochemical workstation, a platinum net is used as a counter electrode, and a reference electrode is Ag/AgCl; the electrochemical scanning voltage is 0.5-5V in forward direction, and the forward direction voltage is kept electrified for 5-90 min.

2. The method of claim 1, wherein: the black phosphorus crystal raw material adopts a smooth surface structure, the thickness is not less than 0.1cm, and the plane size is between 0.5 and 2 cm.

3. The method of claim 1, wherein: the electrochemical scanning voltage is 0.5V in the forward direction, and the forward direction voltage is kept electrified for 40 min.

4. The method of claim 1, wherein: the prepared black phosphorus oxide material with red luminescence has a photoluminescence spectrum with an inner wavelength of 650nm and a half-peak width of 100 nm.

5. Use of a black phosphorus oxide material having red luminescence, which is prepared by the method of claim 1, wherein: is used for manufacturing photoelectric devices.

Technical Field

The invention belongs to the technical field of electrochemistry, and particularly relates to a preparation method of a black phosphorus oxide material with red luminescence.

Background

Black phosphorus is the most stable allotrope of phosphorus, having a graphite-like layered structure. The black phosphorus with the single atomic layer can be obtained by a mechanical stripping method. Monoatomic layer of black phosphorus, calledPhosphorenes, a novel graphene-like structure, also have excellent carrier transport properties, and are reported to have carrier mobilities of up to 1000 cm for black phosphorus (thickness about 10 nm) of a few atomic layer thickness²V^-1s^-1Unlike graphene, however, where a single atomic layer of black phosphorus has an intrinsically narrow band gap, theoretical calculations predict that a few atomic layers of black phosphorus have band gaps of about 0.5-1.2 eV, with corresponding photon energies likely in the Near Infrared (NIR) band suitable for optical communications. The band gap of the bulk black phosphorus crystal is smaller and is only 0.2-0.3 eV. Therefore, the application of black phosphorus in the photoelectric field related to the visible light band is greatly limited.

Black phosphorus is a two-dimensional atomic layer material which has been developed in recent years, and the research on the preparation, structure and properties of black phosphorus is relatively lacking. In particular, the improvement of the black phosphorus structure to obtain specific photoelectric properties has been much less studied. Electrochemical treatment is an important method for modifying a two-dimensional material, and the invention patent application CN 110451468A discloses a magnetic black phosphorus two-dimensional material and a preparation method thereof, wherein an electrochemical method is adopted to treat black phosphorus crystals, and the black phosphorus crystals are connected with an electrode of a power supply and are immersed in an electrolyte containing magnetic ions under a shading environment. In order to avoid black phosphorus oxidation, the electrochemical reaction is carried out in an inert atmosphere, and the magnitude of forward voltage is 10-50V; and/or the reaction time is 24-48 h. So far, there is no published method to obtain black phosphorus related structures and materials with red luminescence.

Disclosure of Invention

In order to expand the application of black phosphorus related structures and materials in the photoelectric field related to the visible light wave band, the invention designs a method for oxidizing black phosphorus crystals by using an electrochemical method, thereby realizing the change of the electronic state structure of the black phosphorus crystals and obtaining the luminescence of the visible light wave band. The preparation process has the advantages of simple flow, low cost and stable obtained product, and expands the potential application of black phosphorus related structures and materials in the field of photoelectric devices.

In order to achieve the purpose of the invention, the invention adopts the following technical scheme: an electrochemical preparation method of a black phosphorus oxide material with red luminescence comprises the following steps:

a. preparing a phosphate buffer solution as an electrochemical electrolyte;

b. clamping the black phosphorus crystal raw material on a working electrode of an electrochemical workstation;

c. carrying out electrochemical scanning, and oxidizing the black phosphorus crystal by using electrochemical reaction;

d. and the oxidized sample is subjected to structural and luminescence characterization, so that the black phosphorus oxide is ensured and the sample has red luminescence characteristics.

Preferably, the phosphate buffer solution in step a is a phosphate buffer solution with a neutral pH value, and is prepared by mixing 0.1M potassium dihydrogen phosphate and 0.1M dipotassium hydrogen phosphate aqueous solution, during the preparation process, the mixture should be fully stirred in the air for not less than 1 hour, and after the preparation, a proper amount of electrolyte is injected into the electrolytic cell. During the preparation of the electrolyte, the electrolyte is sufficiently stirred in the air in order to dissolve oxygen in the electrolyte as much as possible.

Preferably, the black phosphorus crystal raw material in the step b is preferably a block material with a smooth surface structure and a moderate size, the thickness is not less than 0.1cm, and the plane size is between 0.5 and 2 cm; the size is not suitable to be too large or too small, if the size is too small, the working electrode is difficult to be stably clamped on the working electrode of the chemical workstation, and if the size is too large, the working electrode is difficult to enter the electrolytic cell; the black phosphorus crystal should be in stable electrical contact with the electrochemical workstation; the black phosphorus crystal should be kept immersed in the electrolyte obtained in a large area;

preferably, the line electrochemical scanning of step c is performed on a three-electrode electrochemical workstation, using a platinum mesh as a counter electrode and a reference electrode of Ag/AgCl. After the step b is finished, applying a proper forward voltage (0.5-5V) to the electrochemical workstation, and keeping the forward voltage electrified for 5-90 min; after the electrochemical scanning is finished, the black phosphorus crystal after the oxidation treatment is taken down, and the surface is washed by deionized water for a plurality of times so as to wash away phosphate which is possibly adsorbed on the surface of the material. After being lightly dried by a blower, the mixture is stored in a closed and dry environment. More preferably, the electrochemical scanning voltage is 0.5V in the forward direction, and the forward voltage is maintained for 40 min.

The electrochemical scanning parameters are the technical key of the invention, the electrochemical reaction should be carried out in the air environment, and the oxygen dissolved in the electrolyte is the necessary condition for the oxidation of the black phosphorus crystal. Further, the electrochemical applied voltage and the energization time are critical in determining the degree of oxidation, and when the applied voltage is too low (0.5V or less) and the energization time is short (5 min or less), significant oxidation is not sufficiently caused. And when the voltage is too high (above 5V) and the energization time is too long (above 90 min), the black phosphorus crystal may be damaged.

And (4) carrying out structural and luminescence characterization on the oxidized sample to obtain the black phosphorus oxide and the black phosphorus oxide with red luminescence characteristics. The raman spectrum and the photoluminescence spectrum are simultaneously tested in a confocal spectroscopic measurement system. New vibration modes below 300 wave numbers and A around 360 wave numbers appear in the Raman spectrum_1gThe occurrence of mold cleavage is an important feature of the successful oxidation of the black phosphorus crystal. Furthermore, when the oxidized black phosphorus crystal was successfully oxidized and the luminescence spectrum thereof was measured, it was possible to observe a broad-spectrum red light emission having a center wavelength of about 650nm and a full width at half maximum of about 100 nm.

The invention realizes the oxidation of the black phosphorus crystal by a manually controllable method for the first time, and actually the black phosphorus crystal can be oxidized when being stored in a humid environment, and compared with the unconscious oxidation, the invention has the remarkable differences and outstanding advantages that:

1, the electronic state structure of the black phosphorus crystal cannot be fundamentally changed by the unintentional oxidation, and the black phosphorus crystal does not emit light in a visible light band. The invention can regulate and control the electronic state structure of the black phosphorus crystal, thereby realizing the luminescence with the central wavelength of about 650 nanometers.

2, the invention can realize the regulation and control of the oxidation degree by regulating the working voltage and the oxidation time of the electrochemical oxidation.

Drawings

FIG. 1 is a scanning electron microscope picture of the original black phosphorus crystal of the example;

FIG. 2 is a scanning electron microscope photograph of the black phosphorus oxide material obtained in the example;

FIG. 3 is a Raman spectrum of the black phosphorus oxide material obtained in the example;

fig. 4 is a photoluminescence spectrum of the black phosphorus oxide material obtained in the example.

Detailed Description