Can this be used within a Static method?

We can't use this in static method because keyword this returns a reference to the current instance of the class containing it.

Static methods (or any static member) do not belong to a particular instance. They exist without creating an instance of the class and call with the name of a class not by instance so we can't use this keyword in the body of static Methods, but in case of Extension Methods we can use it as the functions parameters.