Second Time-Scale Synthesis of High-Quality Graphite Films by Quenching for Effective Electromagnetic Interference Shielding

Graphite film has many remarkable properties and intriguing applications from energy storage, electromagnetic interference (EMI) shielding, and thermal management to ultraviolet lithography. However, the existing synthesis methods require an extremely high processing temperature of ∼3000 °C and/or long processing time of typically hours. Here, we report an ultrafast synthesis of tens of nanometer-thick high-quality graphite films within a few seconds by quenching a hot Ni foil in ethanol. The vertical growth rate can reach over 64 nm s^-1, which is more than 2 orders of magnitude higher than those of the existing methods. Moreover, the films show excellent electrical conductivity (∼2.6 × 10⁵ S/m) and mechanical strength (∼110 MPa) comparable to or even better than those synthesized by chemical vapor deposition. As an example, we demonstrate the potential of these graphite films for effective EMI shielding, which show a record absolute shielding effectiveness of 481,000 dB cm² g^-1, outperforming all the reported synthetic materials.