Adsorption behavior of formaldehyde on ZnO (101¯0) surface: A first principles study

In a first principles study of the formaldehyde adsorption on ZnO surface, we found a novel chain adsorption structure on ZnO (101¯0) plane. This adsorption structure results from the electrostatic interactions between those adsorbed formaldehyde molecules and the unique arrangement of Zn-O surface dimers on (101¯0) plane. This adsorption mechanism has the potential to extend to other wurtzite materials’ (101¯0) plane and other similar cases. As the physical adsorption configurations are unstable, the chemical adsorption has to happen. The electronic properties show that the C[dbnd]O double bond in CH ₂ O turns into C–O single bond and the highest occupied molecule orbital (HOMO) of formaldehyde is lifted into ZnO band gap becoming the hole trapping center. These results may be meaningful for formaldehyde degradation and detection.