Thermal Reduction of MoO3 Particles and Formation of MoO2 Nanosheets Monitored by In Situ Transmission Electron Microscopy

• DOI: 10.1021/acs.jpcc.3c05159
• Publication Date: 2023-10-26T13:25:04Z
• Authors: Xiaodan Chen; Roos M. de Boer; Ali Kosari; Heleen van Gog; Marijn A. van Huis
• Keywords: General Energy; Physical and Theoretical Chemistry; Electronic, Optical and Magnetic Materials; Surfaces, Coatings and Films

Nanoscale forms of molybdenum trioxide have found widespread use in optoelectronic, sensing, and battery applications. Here, we investigate the thermal evolution micrometer-sized particles during situ heating vacuum using transmission electron microscopy observed drastic structural chemical changes that are strongly dependent on rate. Rapid (flash heating) MoO3 to a temperature 600 °C resulted large-scale formation MoO2(001) nanosheets were formed wide area around reducing particles, within few minutes time frame. In contrast, when heated more gently, initially single-crystal reduced into hollow nanostructures with polycrystalline MoO2 shells. Using density functional theory calculations employing DFT-D3 functional, surface energy MoO3(010) was calculated be 0.187 J m–2, activation for exfoliation van der Waals bonded (010) layers 0.478 m–2. Ab initio molecular dynamics simulations show strong fluctuations distance between layers, where vibrations lead additional separations up 1.8 Å at °C. This study shows efficient pathways generation either or very high effective areas beneficial