Thermally stable Ni@SiO2 core-shell nanoparticles for high-temperature solar selective absorber

• DOI: 10.1016/j.solener.2021.09.076
• Publication Date: 2021-10-02T05:57:19Z
• Authors: Dawei Ding; Wenjing Wei; Xiaoping He; Shujiang Ding
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; 7. Clean energy

Abstract Improving the thermal stability of solar absorbers persists to be the challenge for solar-thermal technologies operated at high temperatures, such as concentrated solar power trough system. Herein, we report a rationally designed solar selective absorber based on Ni@SiO2 core–shell nanoparticles with significantly improved thermal stability at temperatures up to 700 °C. Ni nanoparticles were encapsulated into dense ceramic SiO2 nanoshells, which effectively prevented the formation of Ni-alloys and oxides by inhibiting diffusion of both inclusion Ni and metallic atoms from the substrate at high temperatures. Besides, the spectral absorption properties of the Ni@SiO2 solar absorber can be optimized by tuning the sizes of Ni cores and absorbing structures. As a result, high solar absorptance (∼0.913) but low thermal emittance (∼0.085) have been achieved for a double-layer Ni@SiO2 absorber with Ni cores of 40 nm and 80 nm. The excellent thermal stability and high absorption selectivity of the Ni@SiO2 solar absorber indicate its great potential for high-temperature solar-thermal conversion applications.