Synergistic effect of diatomic materials on efficient formaldehyde sensing and degradation

A high-sensitivity sensor for formaldehyde (HCHO) is crucial in environmental detection and human health studies. However, the development of sensing materials with remarkable adsorption capacity remains a challenge. In this study, we employed density functional theory to screen twenty-seven transition metals as potential single atom (SA) and diatomic (DA) adsorption materials for detecting HCHO. Among them, Hf 2 -C 2 N exhibited excellent HCHO adsorption capability among fifty-four candidate materials due to its more negative adsorption energy (−7.32 eV). Through extensive electronic structure and orbital analyses, we elucidated that the enhanced activity of Hf DAs, acting as the active site for HCHO adsorption, was attributed to the introduction of an additional Hf atom in Hf 2 -C 2 N. Furthermore, we discussed in detail the degradation process of HCHO on Hf 2 -C 2 N using transition state analysis which revealed a low potential barrier (2.1 eV), indicating its potential as a high-performance catalyst. This work not only screens a bifunctional catalyst for efficient adsorption and degradation of HCHO but also provides valuable insights for further experimental exploration. Twenty-seven transition metals were screened as potential single atom and diatomic materials for detection and degradation of HCHO.