Thermal stability of Ni3ZnC0.7: As tunable additive for biomass-derived carbon sheet composites with efficient microwave absorption

With the rapidly development of radar detection technology and the increasingly complex application environment in military field and electromagnetic pollution surrounded by electron devices, increasingly demand is needed for electromagnetic wave absorbent materials with high absorption efficiency and thermal stability. Herein, a novel Ni3ZnC0.7/Ni loaded puffed-rice derived carbon (RNZC) composites are successfully prepared by vacuum filtration of metal-organic frameworks gel precursor together with layered porous-structure carbon and followed by calcination. The Ni3ZnC0.7 particles uniformly decorate on the surface and pores of puffed-rice derived carbon. The puffed-rice derived carbon@Ni3ZnC0.7/Ni-400 mg (RNZC-4) sample displayed the best electromagnetic wave absorption (EMA) performances among the samples with different Ni3ZnC0.7 loading. The minimum reflection loss (RLmin) of the RNZC-4 composite reaches −39.9 dB at 8.6 GHz, while widest effective absorption bandwidth (EAB) of RNZC-4 for RL < −10 dB can reach 9.9 GHz (8.1–18 GHz, 1.49 mm). High porosity and large specific surface area promote the multiple reflection-absorption effect of the incident electromagnetic waves. The Ni3ZnC0.7 nanoparticles provide a large number of interfaces and dipole factors. Analysis reveals that the RNZC-4 remained general stability under 400 °C with formation of a small amount of NiO and ZnO phases. Surprisingly, at such high temperature, the absorbing properties of the material are improved rather than decreased. Obviously, the material still maintains good electromagnetic wave performance at high temperature, and implies that the absorber shows good performance stability. Therefore, our preparations exhibit potential applications under extreme conditions and a new insight for the design and application of bimetallic carbides.