Morphology-Controlled In2O3 Nanomaterials with Excellent Electromagnetic Wave Absorption Properties

In the field of electromagnetic wave (EMW) absorption, the development of nonmagnetic materials with strong absorptive performance, low filling ratio, and wide bandwidth is of significant importance. In this work, five morphologies of In₂O₃ nanomaterials are prepared by simple hydrothermal and annealing processes. The morphologies of products (including the lamellar flower-, lychee-, cheese-, nanocube-, and urchin-like In₂O₃) are obtained by using different surfactants. The experimental results indicate that the lamellar flower-like In₂O₃ has a minimum reflection loss (RL_min) of −52.04 dB (1.74 mm) and an effective absorption bandwidth (EAB) of 5.97 GHz (1.92 mm). Correspondingly, the RL_min and EAB of lychee-like In₂O₃ are −70.61 dB (2.55 mm) and 5.57 GHz (1.72 mm), respectively. A large specific surface area about lamellar flower-like In₂O₃ can effectively increase the reflection and scattering paths of EMW inside the absorbing material, which is beneficial for the attenuation of EMW. This work not only demonstrates the great potential of In₂O₃ in practical EMW absorption applications but also extends the research on nonmagnetic materials in the EMW absorption field.