Excellent Gas-Sensitive Capabilities of Co(HXTP) for Detecting Combustion Process Gases: A Theoretical Study.

Combustion processes produce noxious gases, causing environmental pollution and health risks, which require high-performance sensing materials. Herein, metal-organic framework structures (MOFs) Co(HXTP) (X = H, I, T) with superior conductivity and sensing properties are employed based on density functional theory (DFT) calculations. Adsorption energies of Co(HXTP)@gas are exceptionally outstanding in the realm of gas-sensitive material. Co(HXTP) bases exhibit a responsive behavior toward the gas by comparing the work function and have a short recovery time (τ). Our results demonstrate that Co(HHTP) (τ = 1.226 s) and Co(HITP) (τ = 19.441 s) can serve as gas-sensitive materials for detecting O at 298 K, whereas Co(HTTP) (τ = 694.226 s) can be used for CO at 498 K. Moreover, excellent gas-sensitive properties arise from chemical interactions, such as the electron "donation-backdonation" mechanism between gas and substrate (σ → 3d and 3d , 3d → π*), and the simultaneous refilling of the d-suborbitals (3d → 3d , 3d ) within Co atoms. The descriptor φ demonstrates excellent predictive capability for both the adsorption and response of gas-sensitive materials. Our findings provide valuable insights into the design of gas-sensitive materials in this class of TM(HXTP) structures.