A method for manufacturing a plurality of nanostructures (101) on a substrate (102). The method comprises the steps of: depositing a bottom layer (103) on an upper surface of the substrate (102), the bottom layer (103) comprising grains having a first average grain size; depositing a catalyst layer (104) on an upper surface of the bottom layer (103), the catalyst layer (104) comprising grains having a second average grain size different from the first average grain size, thereby forming a stack of layers comprising the bottom layer (103) and the catalyst layer (104); heating the stack of layers to a temperature where nanostructures (101) can form; and providing a gas comprising a reactant such that the reactant comes into contact with the catalyst layer (104).