Preparation method and application of graphene and titanium dioxide photo-catalysis nano-crystals

Abstract

The invention discloses a preparation method and application of graphene and titanium dioxide photo-catalysis nano-crystals and belongs to the technical field of inorganic composite materials. The preparation method comprises the following steps: putting graphite powder and sodium nitrate into a flask; adding concentrated sulfuric acid and slowly adding potassium permanganate into the flask; stirring in an ice-bath environment and slowly dropwise adding hydrogen peroxide into the flask; washing with hydrochloric acid under a high-speed centrifuging condition to obtain a graphene oxide ethanol solution; after diluting, slowly adding tetrabutyl titanate, and slowly dropwise adding stronger ammonia water; putting a separated product into an air blowing drying box and drying; putting a dried product into a tubular furnace and inert gas atmosphere, and calcining; cooling to obtain the graphene / titanium dioxide photo-catalysis nano-crystals. The growth of titanium dioxide nano-crystals on graphene can be accurately regulated and controlled and a homogeneous nucleation phenomenon of titanium dioxide in a liquid phase is avoided; a preparation process is moderate and easy to observe, a high-pressure reaction environment is not needed and the safety and reliability of operation are improved.

Description

technical field [0001] The invention relates to the technical field of inorganic composite materials, in particular to a preparation method and application of graphene titanium dioxide photocatalytic nanocrystals. Background technique [0002] Graphene is a stable two-dimensional planar functional material with excellent electrical conductivity, light transmission and large specific surface area, so it can show its excellent optical, electrical and catalytic properties. At present, graphene has received extensive attention. By combining graphene with semiconductor nanomaterials, composite materials with excellent properties can be prepared. When the prepared material is irradiated by an excitation light source, photogenerated electrons can be transferred from semiconductor particles to graphene, effectively inhibiting the recombination of photogenerated electrons and holes, improving the lifetime of photogenerated electrons and holes, thereby improving photocatalytic effici...

AI Technical Summary

Problems solved by technology

[0003] Titanium dioxide is a non-toxic semiconductor material. Due to its excellent photoelectric conversion ability, excellent stability, low price and easy availability, it is widely used in photovoltaic solar cells, photocatalytic reactions, photocatalytic degradation, and sewage treatment. It has a wide range of applications, but due to its wide band gap, it has the disadvantage of slow degradation activity.

[0009] The existing technologies represented by the above-mentioned patent documents are mostly carried out by hydrothermal method, which has many defects, such as: the positioning and growth of titanium dioxide nanocrystals on the graphene sheet cannot be accurately controlled, and the homogeneous phase of titanium dioxide in the liquid phase cannot be avoided. Nucleation phenomenon; the hydrothermal method is carried out in a hydrothermal kettle, and the required experimental conditions are relatively harsh, usually requiring a high-pressure environment, and the reaction time is long, generally 6-12 hours, and the safety and reliability of the preparation operation is low; The method usually reacts in a closed container, and the whole reaction process cannot be observed and is not intuitive.

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