1-Propanol on WO3(100)

After exposure of the tungsten oxide surface to 1-propanol at room temperature than annealing to 400 K to form an alkoxide, white "balls" appear on the surface (a,b). Interestingly, the balls display no preference to decorate the dark trenches which are defects that resemble steps, rather the molecules bond to the terraces. High biases (2-3 V) were required to image the alkoxide. When the bias is reduced the image becomes blurry (c) and the interaction with the tip causes the molecules to swept away by the tip (d). When the bias is increased and we pan out we see a denuded square corresponding to the area we were imaging (e). We can now see the underlying c(2x2) structure of the tungsten oxide surface. Thus we now have a method to image the molecules and identify their location, and then remove the molecules and characterize the structure of the adsorption site.