Regulation of component transformation in MOF-derived vanadium oxide@C spindles for high-performance electromagnetic wave absorption

Metal-organic framework (MOF) derived carbon-based materials had drawn increasing research attention for developing advanced absorbers. In this work, vanadium (V)-MOF derived porous V oxide@C (vanadium oxide encapsulated carbon material) spindles had been successfully prepared by a two-step method. After sintering at different temperatures in nitrogen atmosphere, a series of phase transformation processes were generated in this V-MOF, where variant V oxide@C composite materials including V2O5, V2O3, VO are formed, respectively. Among these samples, V oxide@C with a sintering temperature of 500 degrees C exhibited the best EM wave absorption performance when the main form of vanadium oxide was V2O3. The minimum reflection loss of V oxide@C could reach - 19.5 dB, and the effective absorbing bandwidth is 5.2 GHz (from 12.8 GHz to 18 GHz) with the absorbent thickness of 1.7 mm, almost covering the whole Ku band. It is believed that the V oxide@C composite materials are expected to be novel absorbers in the electromagnetic wave absorption field. (C) 2021 Elsevier B.V. All rights reserved.