Controllable HCHO and CH3OH catalytic reduction on the surfaces of ferroelectric In2Se3 monolayer with intrinsic defect

In this work, we studied different behaviors of the chemical reaction on the two surfaces of two-dimensional ferroelectric In2Se3 which is used as the catalyst. The reduction reactions of organic formaldehyde and meth-anol on the In2Se3 surface with single In vacancy are investigated from first-principles. We found that the conductive electron states are localized in the region of vacancies originated from the un-paired electrons of the dangling bonds. Considering the acidic environment of the reaction, the hydrogen atoms are used to saturate the three dangling bonds in each In vacancy. By reporting the evolution of total free energy of the reaction, we show the features that the reduction reactions are more readily at one surface than the one at the other surface of substrates. Since the asymmetric two surfaces can be equivalently switched by external electric fields, the results of our work suggest an effective approach of controlling catalytic reaction in practical applications.