Improving on the very high temperatures used in solid-state synthesis routes to prepare CCTO ignited the idea of using oxalate routes which make use of organic solvents in the synthesis of CCTOX as oxalate intermediates to the decomposition product, CCTO. The use of commercial oxalic acids and oxalate has not only recorded a solubility problem which reflects on the size, shape, homogeneity, and morphology of the final product but also has an environmental impact originating from the solvents used. Both the composition and morphology of these inhomogeneities play a role in the behaviour of the final product, pointing out the need to assess the dependence of size, shape, homogeneity, and morphology and the material performance on the sample synthesis history. In this study, nanosized particles of calcium copper titanium oxide, CaCu₃Ti₄O₁₂ (CCTO), were successfully synthesized by pyrolysis of the corresponding heterometal oxalate precursors obtained via coprecipitation using the edible carambola fruit juice as a precipitating agent and investigated in detail. The precursors were characterized, and the results revealed the formation of a single molecular precursor represented by the formula CaCu₃(TiO)₄(C₂O₄)₈·9H₂O (CCTOX). The decomposition products, obtained via calcination in air, were subsequently subjected to thermal treatments at different temperatures for 4 hours. The morphology and microstructure were characterized, and analysis showed the formation of a single phase, CaCu₃Ti₄O₁₂ (CCTO) with CuO and CaTiO₃ as impurity. It was observed from microscopy that the samples obtained from sintering at 600°C for four hours had discrete particles with regular morphology, limited size distribution, high degree of homogeneity, and multiple dimensions ranging between 10 and 35 nm and showed some degree of ellipticity in shape. Increasing the sintering temperature from 600°C to 700°C and 800°C increased the grain growth in the ceramic as well as the densification. The method makes advantage of the fact that oxalate precursors decomposed at relatively lower temperatures and the fact that the oxalate in the juice is in the solution which downplays both the solubility and environmental pollution problems since no additional solvents are used.

中文翻译：

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洋杨桃果汁中草酸前驱体的纳米级CaCu3Ti4O12的绿色合成，表征及对钙钛矿的热分解。

改进用于制备CCTO的固态合成路线所用的极高温度，激发了使用草酸盐路线的想法，该路线在CCTOX的合成中利用有机溶剂作为分解产物CCTO的草酸盐中间体。使用商业草酸和草酸盐不仅记录了溶解度问题，反映了最终产品的大小，形状，均质性和形态，而且还对所用溶剂产生了环境影响。这些不均匀性的组成和形态均在最终产品的行为中起作用，指出需要评估尺寸，形状，均质性和形态以及材料性能对样品合成历史的依赖性。在这项研究中，钙铜钛氧化物CaCu的纳米颗粒使用食用杨桃果汁作为沉淀剂，通过共沉淀获得的相应杂草酸草酸盐前驱体热解，成功合成了₃ Ti ₄ O ₁₂（CCTO），并进行了详细研究。对前体进行了表征，结果表明形成了由分子式CaCu ₃（TiO）₄（C ₂ O ₄）₈ ·9H ₂表示的单分子前体O（CCTOX）。通过在空气中煅烧获得的分解产物随后在不同温度下经受热处理4小时。表征了形貌和微观结构，分析表明形成了单相CaCu ₃ Ti ₄ O ₁₂（CuTO）和CaTiO ₃作为杂质。从显微镜下观察到，在600℃下烧结4小时获得的样品具有离散的颗粒，其具有规则的形态，有限的尺寸分布，高度的均质性以及在10至35nm之间的多个尺寸，并且在一定程度上具有椭圆度。形状。将烧结温度从600℃提高到700℃和800℃会增加陶瓷中的晶粒生长以及致密化。该方法利用以下事实：草酸盐前体在相对较低的温度下分解；以及汁液中的草酸盐存在于溶液中的事实，由于不使用额外的溶剂，因此降低了溶解性和环境污染的问题。