Progressive
advancement in modern detection technologies entails
multispectral compatible camouflage. Previously, infrared camouflage
materials, such as photonic crystals and metamaterials, have been
developed, but improved multispectral compatibility, easy fabrication,
and cost-effectiveness remain a challenge. Here, we report a nanostructured
composite film based on oxalate-rich porous alumina (OPA) for visible-to-infrared
compatible camouflage and simultaneous thermal management. The nanostructured
composite film consists of a visible-transparent OPA layer, a composite
layer of OPA/metal oxides, and an aluminum substrate. Each functional
layer exhibits desirable reflection/emission properties for infrared
and visible camouflage. Infrared camouflage is realized by the high
reflection (low emission) of the metal substrate in both infrared-detected
bands (3–5 and 8–14 μm). Meanwhile, radiative
cooling arising from the intrinsic absorption of oxalate in the undetected
band (5–8 μm) enhances surface heat dissipation. In addition,
background-matching colors can be tuned by the metal oxides in the
composite layer for visible camouflage, such as green for forest and
brown for desert. This work provides a facile strategy to modulate
multispectral absorption/emission properties with much flexibility
and thus has great potential for energy conversion and stealth applications.