Preparation method of low-cost selective coating for solar thermal collector

Abstract

The invention aims to provide a preparation method of a low-cost selective coating for a solar thermal collector, comprising the following steps: (1) adding alkali and oxidant into deionized water at a molar ratio of (1-5):1, fully stirring to obtain a first evenly-mixed solution, and putting into a constant-temperature water bath of 20-100 DEG C; (2) mixing ammonium persulphate, ammonium chloride, deionized water and pyridine at a molar ratio of 1:(1-10):(10-100):(0-0.1), and fully stirring to obtain a second evenly-mixed solution; (3) slicing a copper sheet into proper size, and putting the sliced copper sheets into the solution obtained in the step (2) to react for 10-30 minutes; putting into the solution obtained in the step (1) to react for 5-60 minutes; and taking out after the reaction, washing with deionized water, and drying in air at 50-100 DEG C to obtain the selective coating for a solar thermal collector. The method has low cost and is easy to widely popularize. Meanwhile, the prepared coating not only has good solar absorbability, but also has lower emission characteristics in the infrared radiation wave band.

Description

technical field [0001] The invention belongs to the field of solar energy utilization materials, in particular to a preparation method of a cheap selective coating for solar heat collectors and its application in solar heat collection. technical background [0002] As an inexhaustible and inexhaustible green energy source, solar energy has been widely concerned by people. The use of solar energy includes photothermal, photoelectric, photochemical, etc., among which photothermal utilization is one of the most traditional and effective ways of solar energy utilization. Solar collectors are one of the key components of solar thermal utilization. To achieve efficient thermal utilization of solar collectors, solar selective coatings that can match the solar spectrum and have a small emissivity in the thermal radiation band are One of the essential parts. At present, various techniques such as electroplating, spray coating, physical vapor deposition and chemical vapor deposition...

AI Technical Summary

Problems solved by technology

At present, there are many methods for preparing cuprous oxide. In industry, there are mainly sintering methods, electrolysis methods, and glucose reduction methods. For copper, after cooling in an inert atmosphere, use grinding equipment to grind the sintered product. This method consumes a lot of energy, and the purity of cuprous oxide is relatively low, and it is powder. When preparing the coating in the later stage, it is necessary to find Adhesives with good infrared and low emission characteristics are more difficult

Although the copper electrode electrolysis method can produce better quality cuprous oxide powder and film, but the power consumption is large, the production efficiency is relatively low, and the waste liquid of electrolysis will cause relatively large pollution to the environment, etc.

The glucose reduction method needs to consume relatively expensive raw materials, and the production cost is relatively high

Many researchers have improved the preparation method for preparing cuprous oxide. The Li Yadong research group of Tsinghua University provided a method for rapidly synthesizing quasi-monodisperse cuprous oxide nanospheres at low temperature in the Chinese patent (CN1759965A), but in this method Some volatile organic solvents need to be used, and it is difficult to prepare a film with a certain thickness by this method

Han et al. (Thin Solid Films 517 (2008) 1195-1199) prepared a CuO film by magnetron sputtering and then heat-treated it at 500°C in an air atmosphere, and then deposited the CuO film on N 2 Preparation of phase-pure Cu by microwave plasma sintering under atmosphere 2 O thin film, the preparation process of this method is not only complicated but also requires high temperature, which is not suitable for the preparation of large-area and low-cost Cu 2 O film

Yang et al. (Thin Solid Films 517 (2008) 967) used Cu 2 O as the target material, pure phase Cu was prepared by radio frequency magnetron sputtering 2 O thin film, but because the efficiency of RF sputtering itself is relatively low, and Cu 2 O target production itself is difficult, making this method also have problems of cost and large area

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