The preparation of a strawberry-like super-hydrophilic surface on the molybdenum substrate

A super-hydrophilic surface was prepared on the molybdenum substrate via a hydrothermal method. The scanning electron microscope (SEM) images show that many crystal grains with the size of about a hundred nanometers grown on the surface, which look like the seeds on the strawberry surface. The analysis by energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) proves that the seeds are MoO2 crystals. The results of wetting test reveal that the water contact angle is nearly 0° and the super-hydrophilicity can stably keep for more than 105 days. The mechanism of the super-hydrophilicity was discussed according to the Wenzel theory.