Design of two-dimensional organic–inorganic heterostructures for high-performance electromagnetic wave absorption

Abstract

The composition control and microstructure design of the absorber are of great importance for achieving excellent electromagnetic wave absorption performance. Vanadium oxide is a typical transition metal oxide with an open skeleton crystal structure, multiple valence states, and high specific area, and is considered a reasonable choice for building high-performance absorbers. To overcome the disadvantages of poor polarization and low conductivity of vanadium oxides, this paper constructs two-dimensional organic–inorganic heterostructural composites by using the strategy of intercalation of conducting polymers of V₂O₅, including PTh-V₂O₅ (PTVOs), PANI-V₂O₅ (PAVOs) and PPy-V₂O₅ (PPVOs). Organic–inorganic heterostructures form numerous heterogeneous interfaces, creating conditions for enhancing composites’ interfacial polarization. Meanwhile, the high conductivity of the organic phase itself also modulates the conductivity of V₂O₅ and enhances the conductive loss of the composites, achieving a synergistic effect between interfacial polarization loss and conductive loss, resulting in excellent electromagnetic wave absorption performance. PTVO-30 achieved an effective absorption bandwidth (EAB) of 6.0 GHz at a thickness of only 1.9 mm. The EAB of PAVO-30 and PPVO-5 was 4.48 GHz (thickness was 1.7 mm) and 5.44 GHz (thickness was 1.9 mm), respectively. Experimental results and theoretical calculations show that the organic–inorganic heterogeneous structure is responsible for the excellent electromagnetic wave absorption performance. In addition, the application of the intercalation strategy to other vanadium oxides and conducting polymers also has the potential to produce good electromagnetic wave absorption performance. This work broadens the path for the rational design of vanadium oxide-based microwave absorbing materials with excellent performance.