A New Route for Surface Modification: Fluorine-Induced Superhydrophilicity

Surface energy and roughness are well-known to be the two key factors for fabricating surfaces with superhydrophilicity or superwettability, and thousands of outstanding achievements have been reported on the basis of these two aspects in recent decades. However, for the physical chemistry community, it is still a challenge for making man-made superhydrophilic surface with universal and easy operating. Here, we describe the development of fluorine-induced superhydrophilicity (FIS) method to fabricate superhydrophilic interfaces via oxy-fluoridation process, in which the fluorine atoms are linked to metal or semimetal atoms in the form of −O–M–F (M is metal or semimetal atom), and a superhydrophilic interface can be obtained owing to the strong polarity bond of (semi)metal oxy-fluoride. Simulation results showed that hydrogen bonds are formed between water molecules and oxy-fluoridized (semi)­metallic interfaces. The value of this FIS has been demonstrated through the successful surface treatment for Ti, Zn, Fe, Co, Ni, and Si and can be expanded to fabricate various superhydrophilic interfaces in the form of −Y–M–X (X = F, Cl, et al.; M = (semi)­metals; Y = O, S, N, et al.) theoretically.