Broge Nils Lau Nyborg, Bertelsen Andreas Dueholm, Nielsen Ida Gjerlevsen, Kløve Magnus, Roelsgaard Martin, Dippel Ann-Christin, Jørgensen Mads Ry Vogel, Iversen Bo Brummerstedt
Center for Integrated Materials Research, Department of Chemistry and iNANO, Aarhus University, DK-8000 Aarhus C, Denmark.
Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany.
Phys Chem Chem Phys. 2024 Apr 17;26(15):12121-12132. doi: 10.1039/d4cp00541d.
Solvothermal synthesis presents a facile and highly flexible approach to chemical processing and it is widely used for preparation of micro- and nanosized inorganic materials. The large number of synthesis parameters in combination with the richness of inorganic chemistry means that it is difficult to predict or design synthesis outcomes, and it is demanding to uncover the effect of different parameters due to the sealed and complex nature of solvothermal reactors along with the time demands related to reactor cleaning, sample purification, and characterization. This study explores the effect on formation of crystalline products of six common anions in solvothermal treatment of aqueous and ethanolic precursors. Three different cations are included in the study (Mn, Co, Cu) representing chemical affinities towards different regions of the periodic table with respect to the hard soft acid base (HSAB) classification and the Goldschmidt classification. They additionally belong to the commonly used 3d transition metals and display a suitable variety in solvothermal chemistry to highlight anion effects. The results of the solvothermal experiments demonstrate a clear effect of the precursor anions, with respect to whether crystallization occurs or not and the characteristics of the formed phases. Additionally, some of the anions are shown to be redox active and to influence the formation temperature of certain phases which in turn relates to the observed average crystallite sizes.
溶剂热合成提供了一种简便且高度灵活的化学处理方法，被广泛用于制备微米和纳米级无机材料。大量的合成参数与无机化学的丰富性相结合，意味着难以预测或设计合成结果，而且由于溶剂热反应器的密封和复杂性质以及与反应器清洗、样品纯化和表征相关的时间要求，要揭示不同参数的影响颇具挑战性。本研究探讨了在水相和乙醇相前驱体的溶剂热处理中，六种常见阴离子对结晶产物形成的影响。研究中包含了三种不同的阳离子（锰、钴、铜），根据硬软酸碱（HSAB）分类和戈尔德施密特分类，它们代表了对元素周期表不同区域的化学亲和力。它们还属于常用的3d过渡金属，在溶剂热化学中表现出适当的多样性，以突出阴离子的影响。溶剂热实验结果表明，前驱体阴离子对是否发生结晶以及所形成相的特征有明显影响。此外，一些阴离子显示出具有氧化还原活性，并影响某些相的形成温度，这反过来又与观察到的平均微晶尺寸有关。
