The objective of this study is a detailed investigation into the preparation of V₂O₅ inverse opals using electrodeposition into preformed colloidal opal templates as a function of electrodeposition parameters (sphere size, voltage, time and substrate). Inverse opals have a range of applications(1-3) and many materials can now be formed into 3D macroporous IO structures.(4-6) Electrodeposition of a VOSO₄ aqueous solution in to the inverse opal template is investigated on three different substrates; transparent conducting oxide glass, stainless steel, and thermally oxidized stainless steel. The electrodeposition follows a diffusion limited growth mode to form 3D porous crystalline V₂O₅ after removal of the colloid photonic crystal template of self-assembled polystyrene spheres. Inverse opals were grown using spheres ranging in diameter from 0.5 µm to 6 µm, and binary inverse opals are also electrodeposited using binary mixtures of sphere size. Analysis of the electrodeposition growth profiles show that IO growth in single and binary opal templates is diffusion limited and that pre-heating stainless steel forms an oxide coating that forces the initial current to increase to a steady state to overcome the resistive oxide, allowing IO to electrodeposit at relatively constant rate. Tortuosity is significantly increased when large sphere diameter templates are used, and especially pronounced when binary opal templates are used, because of interstitial void filling by small spheres in binary opal templates. Raman scattering and X-ray diffraction confirm phase pure, high crystalline quality V₂O₅ is generally formed in all cases (voltages and substrates). Electrodeposition ensures electrical interconnection within the 3D structured material by definition.

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