Figure 2.

(a) Schematic diagram of the electron depletion layer in n-type oxide semiconductor nanowires decorated with p-type oxide semiconductor nanoclusters; TEM images of (b,c) Cr₂O₃-decorated ZnO nanowires; (d) Cr₂O₃-decorated SnO₂ nanowires; (e,f) Co₃O₄-decorated ZnO nanowires; (g) NiO-decorated ZnO nanowires; and (h) Mn₃O₄-decorated ZnO nanowires. Reproduced from [80,81,82,83,84] with permission; (a,e–g) [82,83] Copyright (2011,2012) The Royal Society of Chemistry; (b,c) [80] Copyright (2012) IOP Publishing Ltd.; (d) [81] Copyright (2014) Elsevier; (h) [84] Copyright (2012) American Chemical Society.