Resistant RuO₂/SiO₂ Absorbing Sol–Gel Coatings for Solar Energy Conversion at High Temperature

Abstract

Within the list of the different technologies developed to provide “clean” alternative energy in the future, Concentrated Solar Power systems (CSP), transforming sunlight radiation into thermal or electrical power, are serious candidates. However, some of the main critical issues to the success of the industrial CSP are the solar-to-thermal and the thermal-to-electrical conversion efficiencies, which require robust absorbing systems, capable of withstanding high operating temperatures for decades. In the present communication, we report the preparation of such performing coatings through accurate control of synthesis and processing, achieved using a simple and scalable bottom-up approach. These new systems are composed of highly controlled nanocrystalline RuO2/SiO2 composite designed such that the device stays highly stable in air at 873 K for more than 1000 h while possessing a high solar selectivity (α > 0.94, and ε@873 K <0.28), making them one of the most promising advancements for CSP technologies.

A New Dip Coating Method to Obtain Large‐Surface Coatings with a Minimum of Solution

“…These coatings exhibited rigorously the same characteristics and quality than those obtained from the same solution but using conventional dip‐coating conditions. This conclusion is based on experimental evidences obtained not only with typical sol–gel‐derived mesoporous titania and silica coatings but also with selected high‐added value coatings such as RuO 2 –SiO 2 nanocomposite optical absorber, commercial P3HT conductive polymers, and template block copolymers …”

On‐Demand Preparation of α‐Phase‐Dominated Tungsten Films for Highly Qualified Thermal Reflectors

“…Low infrared emissivity is one of the critical criteria for high‐temperature (>400 °C) solar selective absorbing coatings, in that the thermal radiation loss is proportional to T 4 (T is the operating temperature) . According to Kirchhoff's law, for the opaque materials, their thermal emissivity reduces as increasing the reflectance in the infrared range.…”

Novel Receiver-Enhanced Solar Vapor Generation: Review and Perspectives

“…The study of solar absorber coatings with efficient light absorption properties over a broad range of wavelengths, is essential and critical to many solar thermal applications including solar steam generation [60][61][62][63]. An ideal absorber coating surface eliminates the transmittance and reflectance while exhibiting maximum absorption over a broad spectral range.…”