Construction of hierarchical CuMn2O4/SiC porous microspheres with superb high infrared radiation properties and heat dissipation application

Spinel CuMn 2 O 4 (CMO) has attracted much attention for its exceptional high-temperature high infrared radiation (HIR) emissivity owing to its narrow band gap and unique symmetrical crystal structure. However, the HIR properties at medium/low temperatures limit its extensive application. Herein, we elaborately design and fabricate hierarchical CMO/SiC (CMO-S) hybrid microspheres with wrinkled surface and porous cavity inside via spray-drying method. In the framework, SiC is encapsulated in the porous CMO microspheres, which substantially improves the medium/low-temperature HIR emissivity of spinel CMO and inhibits the oxidative failure of SiC meanwhile. The optimal CMO-S with 10 wt% SiC (CMO-S10) possesses the largest specific surface area, the richest oxygen vacancies, and the smallest band gap, which cooperatively render remarkable HIR emissivity of 0.935 at 30 °C in the 3 ‒ 5 μm band, along with the highest emissivity (0.944) at 300 °C. Moreover, the CMO-S10 based emitting coating exhibits superb heat dissipation efficiency as well thanks to its superb HIR emissivity in 8 ‒ 14 μm band. More essentially, our insights here provide meaningful guidance for rational construction of advanced HIR emitting materials toward efficient heat dissipation, leading more green and sustainable energy consumption.