Pd doping Au(111) surfaces enhancing formaldehyde adsorption: A first-principle study

Toxic gas detection is essential and valuable in pollution monitoring. We used first-principles computations to investigate the adsorption behavior and interaction mechanism of formaldehyde (HCHO) molecules on the Pd/ Au(1 1 1) surface. The results reveal that HCHO is physisorbed on the Au(1 1 1) surface and chemisorbed on the Pd(1 1 1) surface. Furthermore, Pd atoms doped on the Au(1 1 1) surface can significantly increase the adsorption energies and charge transfers of the HCHO molecule, implying that the Pd metal can function as an excellent sensitive material for HCHO response. Additionally, the interaction mechanism between the HCHO molecule and the Pd atoms demonstrated that the two must meet the rules of energy-level matching and orbital wave function maximum overlap perfectly. Our research could pave the way for developing high-performance gas sensors by exploring gas-sensitive materials.