Promoting gas adsorption and charge transfer by activating iron incorporation sites for high performance trimethylbenzene sensing.

The interaction between the surface and the target gas is the key to determining gas sensing performances of sensing materials, and revealing the interaction mechanism between the two still faces challenges. Herein, activating iron incorporation sites strategy is applied to address this issue. The gas sensor based on iron incorporation Co3O4 hierarchical porous architectures shows a significant gas selectivity toward trimethylbenzene, high sensing response, well long-term stability, rapid response/recovery speed and superior humidity resistance. It can be found that the sensing responses are positively correlated with the number and the species of hydrogen substituents on the benzene rings. In contrast, Co3O4 without iron incorporation does not exhibit any gas sensing performance. The density functional theory (DFT) calculations confirm that strong trimethylbenzene adsorption and charge transfer between FeCo sites and benzene ring of gases molecules lead to significantly enhanced trimethylbenzene gas sensing performance.