A method for preparing graphite-like carbon nitride nanosheets by bubble stripping method

Abstract

The invention relates to a method for preparing graphite-like phase carbon nitride nanosheets by a bubble peeling method. It uses melamine as a precursor material and sodium bicarbonate aqueous solution as an electrolyte. The pulse voltage electrolysis method is used for electrolysis, and the graphite-like phase nitride nanosheets are collected. Carbon powder is washed, centrifuged, and vacuum freeze-dried to obtain the final product graphite-phase carbon nitride nanosheets. The thickness of the nanosheets is 1.67nm, and the purity of the product reaches 99.8%. It can catalytically degrade organic matter under light conditions, and can Used in photovoltaic products, it is an advanced method for preparing graphite-like phase carbon nitride nanosheets.

Description

technical field [0001] The invention relates to a method for preparing graphite-like carbon nitride nanosheets by a bubble exfoliation method, and belongs to the technical field of photocatalytic material preparation and application. Background technique [0002] Emerging photocatalytic technology can use sunlight to split water to produce hydrogen and degrade environmental pollutants, making it a research hotspot to solve energy crisis and environmental pollution problems; traditional photocatalysts have narrow light response range, low solar energy utilization, quantum The problem of low efficiency has severely limited their applications; in recent years, organic polymer semiconductor photocatalysts composed of carbon and nitrogen elements—graphite-like carbon nitride, have a narrow band gap and are responsive to visible light. Moreover, it has high chemical stability, easy modification and high photocatalytic performance; the preparation process of graphite-like carbon ni...

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Problems solved by technology

[0002] Emerging photocatalytic technology can use sunlight to decompose water to produce hydrogen and degrade environmental pollutants, making it a research hotspot to solve energy crisis and environmental pollution problems; traditional photocatalysts have narrow photoresponse range, low solar energy utilization, quantum The problem of low efficiency severely limits their applications; in recent years, organic polymer semiconductor photocatalysts composed of carbon and nitrogen elements—graphite-like carbon nitride, respond to visible light due to their narrow band gap, Moreover, it has high chemical stability, easy modification and high photocatalytic performance; the preparation process of graphite-like carbon nitride is simple, and can be prepared by directly heating melamine, urea and dicyandiamide, and can be applied in the field of photocatalysis

[0003] However, graphite-like carbon nitride also has some shortcomings, such as small specific surface area, relatively large band gap width, narrow response range to visible light, low separation degree of photogenerated electrons and holes, and easy recombination; these shortcomings It restricts the application of graphite-like carbon nitride in the field of photocatalysis and energy; because graphite-like carbon nitride is a layered compound, the layered structure is connected by van der Waals force, so two-dimensional carbon nitride can be obtained by exfoliation. Nanosheet structure, the obtained two-dimensional nanosheets increase the surface active sites due to the increase in the specific surface area, and due to the anisotropy of the crystal, the vertical distance for carriers to migrate to the surface is shortened as the thickness of the nanosheets decreases; in addition, Due to the quantum confinement effect, the nanosheets have unique physical and chemical properties, such as the increased band gap can improve the redox ability of the charge carrier; the light absorption and photoresponsive bulk phase of the graphite-like carbon nitride prepared into nanosheets are enhanced ;Through thermal erosion, ultrasonic stripping, chemical stripping, and the use of concentrated hydrochloric acid and concentrated nitric acid to strip graphite-like carbon nitride, graphite-like carbon nitride nanosheets with high specific surface area, good photocatalytic activity and a wide range of applications can be successfully obtained ; The above preparation process is time-consuming and inefficient, and there are safety hazards; therefore, it is necessary to develop a green method to prepare graphite-like phase carbon nitride nanosheets, and this technology is still under scientific research

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