A method of forming nanostructures may include forming a block copolymer composition within a trench in a material on a substrate, wherein the block copolymer composition may comprise a block copolymer material and an activatable catalyst having a higher affinity for a first block of the block copolymer material compared to a second block of the block copolymer material; self-assembling the block copolymer composition into first domains comprising the first block and the activatable catalyst, and second domains comprising the second block; generating catalyst from the activatable catalyst in at least one portion of the first domains to produce a structure comprising catalyst-containing domains and the second domains, the catalyst-containing domains comprising the first block and the catalyst; and reacting a metal oxide precursor with the catalyst in the catalyst-containing domains to produce a metal oxide-containing structure comprising the first block and metal oxide.