Method for preparing bismuth oxychloride/bismuth oxyiodide composite ultrathin nanosheets by ion exchange method

Abstract

The invention discloses a method for preparing bismuth oxychloride / bismuth oxyiodide composite ultra-thin nano-sheets by an ion exchange method. The method comprises the following steps: dissolving bismuth nitrate pentahydrate and polyvinylpyrrolidone in an ethylene glycol solution; stirring at room temperature until the bismuth nitrate pentahydrate and the polyvinylpyrrolidone are completely dissolved; adding a saturated sodium chloride solution in the solution; continuing stirring to obtain a white turbid solution; transferring in a hydrothermal reactor and reacting at the temperature of 140-180 DEG C; drying under vacuum at the temperature of 60 DEG C to obtain a product which is bismuth oxychloride ultra-thin nano-sheets; dispersing the bismuth oxychloride ultra-thin nano-sheets in a saturated potassium iodide solution; and stirring for 3-12 hours at the temperature of 25-50 DEG C to obtain a target product which is the preparing bismuth oxychloride / bismuth oxyiodide composite ultra-thin nano-sheets. The method is simple and easy to operate and good in repeatability; the synthesized bismuth oxychloride / bismuth oxyiodide composite ultra-thin nano-sheets have ultra-thin two-dimensional structures, are large in specific surface area, suitable in band gap and wide in light responding range, and therefore has good application prospect in the related fields such as optics, electrics and thermal physics.

Description

technical field [0001] The invention belongs to the technical field of synthesis of composite photocatalytic materials, and in particular relates to a method for preparing bismuth oxychloride / bismuth oxyiodide composite ultra-thin nanosheets by an ion exchange method. Background technique [0002] In recent years, environmental pollution and energy shortage are major challenges facing mankind. Photocatalytic technology can directly use solar energy as light to drive deep reaction at room temperature, so it has broad development prospects in environmental purification and new energy development. Using semiconductor oxides as catalysts to convert light energy into electrical energy and chemical energy provides us with an ideal method for energy utilization and environmental pollution control. However, the main problems in the research of semiconductor photocatalysts are the high recombination probability of photogenerated electron-hole pairs and the narrow photoresponse range...

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Problems solved by technology

[0004] The patent application number CN201210082112.7 discloses a preparation method of porous bismuth oxyiodide nanophotocatalysis, mainly to solve the existing technical problem of poor photodegradation performance of bismuth oxyiodide in the visible light region, but the preparation process of this method is cumbersome And the use of a large amount of organic solvents is not conducive to large-scale production. In addition, this method only prepares bismuth oxyiodide with a slightly larger specific surface area, and does not fundamentally change the photocatalytic performance of bismuth oxyiodide. There is limited room for improvement.

The patent with the publication number CN101724839A provides a method for preparing BiOCl film by vapor deposition and chemical oxidation. The prepared film has a flower-like structure, but the preparation process requires a complex physical vapor deposition process, special equipment and high-purity Gas is used as shielding gas, the cost is high and the operation is complicated

The patent with the publication number CN101857382A adopts the continuous ion layer adsorption reaction method to prepare BiOI thin film electrodes, which has potential application in the field of solar cells, but this method needs to be repeated many times to obtain the required thin film, and the operation process is relatively cumbersome

The patent with the publication number CN102974373 A discloses a preparation method of a bismuth oxychloride / bismuth oxyiodide heterojunction visible light catalytic material, mainly to provide a material with high catalytic activity and stability, but the preparation of the precursor bismuth oxychloride is time-consuming It is tedious, and the reaction with bismuth oxyiodide in the later stage needs to be calcined, and the formed nanosheets are thicker, which is not conducive to the effective separation of electrons and holes.

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