One-pot synthesis of Cu@porous nitrogen–doped carbon (Cu@PNC) for high-efficiency electromagnetic wave absorption

Abstract

A series of [email protected] (porous nitrogen–doped carbon) samples was successfully prepared through the reduction of Cu2+/g-C3N4 (graphitic carbon nitride) using magnesium, which was used to construct an efficient electromagnetic wave (EMW) absorber. The Cu content in [email protected] was adjusted by changing the amount of Cu(NO3)2∙3 H2O added. Of the three prepared samples, [email protected] exhibited the best EMW absorption properties; that is, the minimum reflection loss (RLmin) was −79.8 dB (d = 3.7 mm) at 5.93 GHz and the effective absorption bandwidth (RL<−10 dB) was up to 5.1 GHz (d = 1.6 mm), with only 5 wt% filled in paraffin. Copper has high electrical conductivity and chemical stability, and these factors helped to enhance the EMW absorption ability and corrosion resistance of the composites. The EMW absorption ability of [email protected] only changed slightly after soaking in acid (1 M) for 28 days. The findings of this research provide a potential route for preparing a Cu-based acid-resistant EMW absorber.