Ultrasonic spray pyrolysis technique to generate a solar absorber coating of Mn-doped α-Fe2O3

Carlos David Hernández-Pérez,Federico González,Enrique Barrera-Calva,Victor Rentería Tapia

doi:10.1051/rees/2021003

Abstract

Today, even though exist a Titanium Nitride Oxide, TiNOX, a very good commercial solar absorber, the efforts to develop new and better solar absorbers like TiNOX are continuing in several laboratories all over the world. In this article, we used the ultrasonic spray pyrolysis technique to prepare manganese, Mn, Mn-doped α-Fe2O3 dark thin films deposited on titanium substrates. The results of an analysis of the solar absorptance and thermal emittance of these films are also presented here; the optical properties depend of the proportions of Mn and iron, Fe, in the spray solution and of the deposit temperature. The best solar absorptance (0.94) and thermal emittance (0.07) values of the films prepared at 600 °C for iron and manganese ion with concentrations of 0.0015 and 0.0035 mol/l, respectively, are comparable with the optical properties of the Titanium Nitride oxide, TiNOX, a very common commercial solar absorber used as an efficient coating for flat plate solar collectors industry.

Highlights

The global demand for energy has increased over time, and solar energy shows promise to significantly contribute to fulfilling current annual energy world demand (630 EJ/yr)
Our topic of research is related to solar absorber materials, which must fulfill high standards of solar absorptance and thermal emittance
In this work we show the results, the chemical synthesis, the structural characterization and the optical properties of a coating based on Mn-doped iron oxide and applied on titanium substrates. (Mn-doped Hematite a-Fe2O3), have been prepared and used for several application, one of the most recent was developed for Yuan et al [4], who prepared this

Summary

Introduction

The global demand for energy has increased over time, and solar energy shows promise to significantly contribute to fulfilling current annual energy world demand (630 EJ/yr). The solar selective absorber coatings exhibit high solar absorptance in the UV-vis region and low infrared emittance, ideal conditions to achieve high efficiency in photo-thermal energy conversion [2]. Our topic of research is related to solar absorber materials, which must fulfill high standards of solar absorptance and thermal emittance. This type of material must be non-toxic, abundant in nature, and stable to a high energy flux and temperature. An example of this type of reference material is TiNOx, which reachs a solar absorptance of 0.95 and an emittance of the order of 0.06 [3]

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