A thermally stable cooler for efficient passive radiative cooling throughout the day

摘要

Passive radiative cooler can dissipate heat from the earth (25 degrees C) to the outer space ( - 270 degrees C) through the atmospheric transparent window (8-13 mu m) by radiation, making the temperature of the cooler lower than that of ambient air. Here, we fabricated a passive radiative cooler that combined silica nanoparticles with anodic aluminum oxide (AAO) template by a simple dip-pulling method, in which the pores of AAO template were filled with silica nanoparticles. The cooler selectively radiates in the atmospheric window while has low absorptivity outside the atmospheric window. Without convection shields, the temperature of the cooler is significantly lower than that of the ambient air throughout the day. Furthermore, the cooler has excellent thermal stability. Even after 4 h of annealing at 600 degrees C, the passive radiative cooling performance of the cooler does not deteriorate.