We report the synthesis of diopside (CaMgSi₂O₆) ceramic powder, a multifunctional material, through an energy efficient, quick and one-step solution combustion (SC) method. Synthesis of diopside by SC method requires oxidizers, especially metal-nitrates, and a suitable fuel. However, unavailability of the silicon-nitrate makes the process of diopside formation by SC method challenging, which forces researchers to synthesize diopside by alternate high temperature solid state reaction route. Here, we demonstrate a simple way to overcome this difficulty by using an extra amount of ammonium nitrate (AN, as the suitable oxidizer), but still using the fumed-silica (an economical ceramic powder) and the solution of Ca-nitrate, Mg-nitrate and the fuel. A systematic investigation was carried out using different extra amounts (0, 5 or 10 mol) of AN, in combination with stoichiometric amounts of one of the three chosen fuels, viz., urea, glycine and alanine. For a specific combination of the fuel and extra oxidizer, namely ‘alanine and 10 mol of AN’, we observed the formation of nano-crystalline diopside phase, which generates enough heat for the incorporation of Si atoms from the SiO₂ precursor into diopside phase directly during the combustion process in one-step. This one-step process does not require any extra high temperature calcination step, thereby saving time, cost and complex equipments, whereas all other powders synthesized using other fuels require an extra calcination step, although the calcination temperature is low (≤ 900 °C), for crystalline diopside phase formation. Hence, our work demonstrates the one-step synthesis of diopside nanopowders by SC method through the direct use of the earth abundant SiO₂ ceramics.

我们报告了一种高效节能，快速且一步一步的固溶燃烧（SC）方法合成了透辉石（CaMgSi ₂ O ₆）陶瓷粉末，一种多功能材料。通过SC方法合成透辉石需要氧化剂，尤其是金属硝酸盐，以及合适的燃料。然而，硝酸硅的不可利用性使得通过SC法形成透辉石的过程具有挑战性，这迫使研究人员通过替代的高温固态反应路线来合成透辉石。在这里，我们展示了一个简单的方法来克服使用硝酸铵（AN的过剩这一困难，为适合氧化剂），但仍使用热解法二氧化硅（一种经济的陶瓷粉末）以及硝酸钙，硝酸镁和燃料的溶液。使用不同的额外量（0、5或10摩尔）的AN与化学计量的三种所选燃料之一（尿素，甘氨酸和丙氨酸）结合进行了系统的研究。对于燃料和额外氧化剂的特定组合，即“丙氨酸和10摩尔的AN”，我们观察到了纳米晶透辉石相的形成，产生了足够的热量，可将SiO ₂前驱体中的Si原子掺入透辉石相中。直接在燃烧过程中一步一步完成。这一步该方法不需要任何额外的高温煅烧步骤，从而节省了时间，成本和复杂的设备，而使用其他燃料合成的所有其他粉末都需要额外的煅烧步骤，尽管煅烧温度低（≤900°C），但对于晶体透辉石相形成。因此，我们的工作证明了直接使用富含土壤的SiO ₂陶瓷通过SC法一步法合成透辉石纳米粉的方法。