HAADF-STEM tomography of a CoPc/ZnO nanowire. (a) HAADF-STEM image of the CoPc/ZnO NW taken at 0° tilt angle. (b) Voxel projection visualisation of the SIRT reconstruction, showing the integrity of the organic core (*) and the nanocolumnar structure of the ZnO shell (**). (c) xy cross-sectional slice, showing a 30° inclination of the branches in the shell. (d) xz cross-sectional slice, showing the rectangular shape of the core and the porous structure of the shell.