Coordination Environment-Mediated Different Heteroatomic Configuration from Doping Strategy for Enhancing Microwave Absorption

Heteroatom doping strategy, as a method to construct complex coordinated configurations, can effectively improve the microwave absorption (MA) performance. However, the correlation between coordination environment/configurations and MA remains ambiguous until now. Herein, S-doped CoxP@C (S-CoP@SC and S-Co2P@SC) composites with 6 and 9 coordination environment are prepared by unsaturated S-doping process. Alteration of the coordination environment resulted in a variety of S coordination configurations, which is used to regulate their proportions. Density functional theory indicated that multiple coordination configurations in S-CoP@SC effectively improved charge transport characteristics and changed charge distribution, which enhanced the conductive and polarization loss. However, for the S-Co2P@SC these coordination configurations reduced the Co2P metallicity, hindering the improvement of conductive loss. As a result, the minimum reflection loss (RLmin) of S-CoP@SC reached -66.0 dB with effective absorption bandwidth (EAB) of 5.0 GHz, compared with the RLmin of CoP@C of -25.7 dB with EAB of 2.1 GHz. In contrast, S-Co2P@SC only improved its RLmin from -30.3 dB (Co2P@C) to -56.6 dB with the low EAB of 2.8 GHz. This work revealed the relationship between coordination environments/configurations and MA performance and provided a novel perspective for the design of absorbers in the MA field at the atomic scale. Three heteroatom configurations in different coordination environments are prepared from S-doping strategy to improve microwave absorption. It is found that S-doped CoP can improve absorption performance more obviously than S-doped Co2P resulting from synergistic effect of heteroatom configurations.image