Study on the dissociation properties and spectra of chlorodifluoromethane under an external electric field

[Display omitted] •The study of dichloromethane under a weak electric field has been carried out for the first time.•The study of potential energy surface was carried out to do further research on dissociation property of dichloromethane.•The degradation of dichloromethane under a certain electric field was verified for the first time.•Concerted dissociation in the dichloromethane molecule was found and calculated for the first time. Chlorodifluoromethane (HCFC-22) is a kind of greenhouse gas, the study of its properties and dissociation methods is of great value to reduce its pollution. Based on the density functional theory (DFT), the structure, spectra and dissociation characteristics of HCFC-22 gas molecules under applied electric field (0 V·nm−1–12.856 V·nm−1) are discussed at the 6–311 G++ (d, p) level. The results all show that HCFC-22 molecule is more easily dissociated under an external electric field. The dissociation characteristic of the molecule is as follow: the dissociation barrier decreases gradually with the increase of external electric field. In addition, the UV–Vis spectrum of HCFC-22 is redshifted and the excitation energy decreases gradually under the action of external electric field. The results of this study provide theoretical support for the application of electric field to degrade HCFC-22 molecules, which can help solve the problem of air pollution.