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O: Fachverband Oberflächenphysik
O 33: Nanostructures at Surfaces: Metals, Oxides and Semiconductors I
O 33.6: Talk
Tuesday, March 21, 2017, 11:45–12:00, REC/PHY C213
Capability of oxygen related defects in controlling the water wetting properties of metal oxide nanostructure — •Kavita Yadav and J. P. Singh — Department of physics, IIT Delhi, New Delhi-110016, India
The water wetting of metal oxide surfaces is generally governed by the surface topography, surface crystallography and the surface defects. A detailed study suggests that the surface defects are most powerful tool for controlling the water wetting properties on metal oxide nanostructures rapidly and economically. The effect of surface crystallography on water wetting properties of metal oxides was studied using first-principles-based DFT calculations for metal oxide crystallographic planes. On the basis of DFT analysis, we conclude that the water dissociation does not depends on the crystallographic surface planes but depends strongly on the surface stoichiometry. Also, the defects related study further support the DFT results and reveals a truth that the highly oxygen deficient metal oxide nanowires show highly water repellent nature similar to a lotus leaf. By utilizing this idea, we have demonstrated a facile approach for the preparation of metal oxide nanowires with tunable surface wettability. The surface wetting properties can be manipulated reversibly in a controlled manner from a superhydrophilic state to a superhydrophobic state by using hydrogen and oxygen gas annealing treatments. The water resistant properties of the metal oxide nanowires coating is found to be durable and can be applied to a variety of substrates.