Fabrication of diameter-modulated and ultrathin porous nanowires in anodic aluminum oxide templates

► AAO templates with modulated pore diameter were fabricated by pulse anodization. ► HA pulse duration tunes the shape of pores and the structure of AAO channels. ► Au, Ag, Ni and Ag-Au diameter-modulated nanowires were synthetized. ► Porous ultrathin Au nanowires were obtained by dealloying Ag-Au nanowires.