Durable, optically transparent, and superhydrophobic coating

A method for preparing a coated substrate, comprising:

• providing a carbon layer disposed on a substrate, the carbon layer having a first side adjacent the substrate and an opposed second side having a textured surface, the carbon layer comprising at least 10 wt. % graphitic carbon and at least 10 wt. % diamond-like carbon, such that the carbon layer comprises at least 80 wt. % of a combined amount of the graphitic carbon and diamond-like carbon;
• providing a hydrophobic silane on the carbon layer, wherein the hydrophobic silane is covalently linked to the graphitic carbon and/or diamond-like carbon, and wherein providing the hydrophobic silane on the carbon layer comprises treating at least a portion of the textured surface of the carbon layer with one or more compounds selected from the group consisting of organosilanes, fluorinated silanes, and disilazanes;
• and
• disposing aerogel adjacent to at least a portion of the textured surface after providing the hydrophobic silane on the carbon layer,
• wherein the textured surface comprises a plurality of spaced features extending perpendicularly to the substrate and comprising at least a portion of the graphitic carbon and diamond-like carbon, the features having an average spacing of 10-2000 nm.