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

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 (alpha > 0.94, and epsilon@873 K <0.28), making them one of the most promising advancements for CSP technologies.