In Situ Studies of Solvothermal Synthesis of Energy Materials

• Published in: ChemSusChem 2014-06, Vol.7 (6), p.1594-1611
• Main Authors: Jensen, Kirsten M. Ø., Tyrsted, Christoffer, Bremholm, Martin, Iversen, Bo B.
• Format: Article
• Language: English
• Subjects: Electric Power Supplies; energy materials; hydrothermal; in situ; Neutron Diffraction; Powder Diffraction; Solvents - chemistry; solvothermal; Temperature; X-Ray Diffraction
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201301042

Solvothermal and hydrothermal synthesis, that is, synthesis taking place in a solvent at elevated temperature and pressure, is a powerful technique for the production of advanced energy materials as it is versatile, cheap, and environmentally friendly. However, the fundamental reaction mechanisms dictating particle formation and growth under solvothermal conditions are not well understood. In order to produce tailor‐made materials with specific properties for advanced energy technologies, it is essential to obtain an improved understanding of these processes and, in this context, in situ studies are an important tool as they provide real time information on the reactions taking place. Here, we present a review of the use of powder diffraction and total scattering methods for in situ studies of synthesis taking place under solvothermal and hydrothermal conditions. The experimental setups used for in situ X‐ray and neutron studies are presented, and methods of data analysis are described. Special attention is given to the methods used to extract structural information from the data, for example, Rietveld refinement, whole powder pattern modelling and pair distribution function analysis. Examples of in situ studies are presented to illustrate the types of chemical insight that can be obtained. In the thick of it: In situ X‐ray and neutron studies of solvothermal and hydrothermal reactions can yield new information on the synthesis of energy material and map the structure–synthesis relationship. Various approaches to in situ powder diffraction and total scattering are reviewed. This review discusses experimental methods as well as strategies for data analysis and highlights the chemical insights that can be obtained from in situ experiments.