3DOM precursor solution

In order to produce 3DOM perovskite mixed metal oxides, selection of precursor solutions is the most important. The precursor solutions should fulfill the following criteria (1) Reactivity of the metal precursor solution should be mild so that it can infiltrate into the voids. If the metal precursor reacts with a functional group on the surface of the template or moisture in the air before it infiltrates the voids, the voids are not filled by the precursor solution. (2) Sufficient metal should be present in the voids to form a macroporous wall, and the metal concentration should therefore be high (usually more than 1 M). When metal concentration is not high enough, repeated infiltration and solidification process should be done. (3) The metal precursor should be solidified in the voids before the template changes their size. In the case of polymer spheres, the polymer... 

Qiu s group reported that 3DOM Er- and Yb-doped CaTiOs was obtained using a precursor solution of Ti(OBu)4 and nitrate salts of Ca, Er, and Yb in EtOH (entry 4) [15]. The solution was infiltrated in voids of the PS template, and calcination of composite at 670 °C in air produced 3DOM Er- and Yb-doped CaTiOs. They reported reduction of upconversion emission if the photonic bandgap overlaps with the Er " emission band. 

Niinez s group reported that HNO3 aqueous solution of La(N03)3, Mn(N03)2, and Sr(N03)2 in the presence of citric acid was also a good precursor solution for the production of 3DOM Lao.8Sro,2Mn03 (entry 15) [31]... 

He s group reported that 3DOM LaFeOs was produced by using a precursor solution of La(NOs)3 and Fe(NOs)3 dissolved in EtOH in the presence of citric acid (entry 32) [46,47]. They reported that the formed 3DOM LaFeOs showed higher performance for chemical looping steam reforming of methane. 

We reported that 3DOM LaA103 was prepared using a precursor solution of La (N03)s and Al(NOs)3 dissolved in eth)dene glycol and MeOH (entry 42) [30]. 

As an example, methods using ethylene glycol-methanol mixed solution of metal nitrates as a precursor solution for the production of 3DOM LaFe03 perovskite mixed oxides with different pore sizes are presented in detail. Physicochemical properties of the products are summarized in Table 6.2. 

Perovskite mixed metal oxides are prepared by solid-state reactions and solution methods. In the solid-state reaction, mixtures of precursors (metal oxides or carbonates) are calcined at near 1000 °C. There has been no report to prepare 3DOM perovskite mixed metal oxides by the solid-state reaction. It is difficult to fill the nanometer-scale voids in the template with solid precursors. 

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