Preparation and Characterization of Co-CuCoMnOx Solar Selective Absorption Coatings

The Co-CuCoMnOx coatings with varying proportions were prepared and investigated to develop a novel metal–ceramic solar selective absorption coating employed at high temperature. The CuCoMnOx powders were synthesized using the solid-phase reaction method. Subsequently, Co-CuCoMnOx coatings were deposited on the surface of 316L steels utilizing the atmospheric plasma spraying (APS) technique. The results showed that the synthesized CuCoMnOx powders were mainly composed of two phases, which were Cu1.5Mn1.5O4 and MnCo2O4. The CuCoMnOx powders had a solar absorptance of 0.929 and an infrared emittance of 0.862, which was considered a good solar absorbent. The synthesized Co-CuCoMnOx coating had a typical thermal spray layered stacking structure. The chemical phases of the coatings were mainly Co, CoO, and CoCuMnOx. Due to the addition of CuCoMnOx inhibiting the oxidation of Co during the thermal spraying process, the 95Co-5CuCoMnOx (wt%) coating exhibited the optimal quality factor (α/ε) of 2.184, with a solar absorptance α of 0.808 and an infrared emittance ε of 0.370, respectively. Moreover, this specific coating demonstrated a good thermal stability for up to 3 h when exposed to an atmospheric environment at 450 °C. The results indicate its significant potential for high-temperature solar selective absorption coating.