Hollow Ni-Co layered double hydroxides-derived NiCo-alloy@g-C3N4 microtubule with high-performance microwave absorption

Hollow microtubule structured nano-/micromaterials of hollow tubular g-C3N4 (TCN) enwrapped with nanosheets were fabricated by a three-step method. By calcining NiCo-layered-double-hydroxides/tubular-cyanuric acid-melamine (NiCo-LDH/TCM) precursor prepared through using 2-methylimidazole as precipitant and methanol as solvent, the as-prepared NiCo-alloy@tubular-g-C3N4 (NC@TCN) shown excellent microwave absorption in the frequency range of 2–18 GHz. The optimal reflection loss (RL) of −35.63 dB was observed at 5.00 GHz and an effective absorption bandwidth of 4.80 GHz at a matching layer thickness of 2.0 mm. Our results indicated that the deposition of NiCo-alloy nanoparticles on g-C3N4 microtubule was an efficient way to fabricate g-C3N4-based high-performance microwave absorbers.