Polymer Gel Templating Synthesis of Nanocrystalline Oxide Anodes

The synthesis of macroporous perovskite La 0.65 Sr 0.3 CoO 3 - δ and spinel NiCo 2 O 4 electrodes was achieved by infiltration of La 0.65 Sr 0.3 CoO 3 - δ and NiCo 2 O 4 colloid solutions inside a polymer gel template followed by calcination at 1100 °C to obtain single-phase materials. Resulting inorganic materials are porous and have a high specific surface area up to 90 m 2 g - 1, average pore diameter ∼450 nm, and 20−50 nm particle size. The structure of inorganic networks shows obvious similarities to the initial polymer gel network. Porous NiCo 2 O 4 spinel can also be obtained from a precursor salt solution, whereas La 0.65 Sr 0.3 CoO 3 - δ perovskite formed after template impregnation from a precursor salt solution has a dense structure with a low specific surface area. Macroporous inorganic networks exhibit high electrocatalytic activity toward oxygen evolution from alkaline water solutions with the efficiency substantially better than that of the film electrodes having a similar composition. The highest activity was observed for the La 0.65 Sr 0.3 CoO 3 - δ perovskite network.