Synthesis of Soluble and Size-Controlled SnO2 and CeO2 Nanocrystals: Application of a General Concept for the Low-Temperature, Hydrolytic Synthesis of Organically Capped Oxide Nanoparticles

Advances in SnO2 for Efficient and Stable n-i-p Perovskite Solar Cells

Perovskite solar cells (PSCs) based on the regular n-i-p device architecture have reached above 25% certified efficiency with continuously reported improvements in recent years. A key common factor for these recent breakthroughs is the development of SnO₂ as an effective electron transport layer in these devices. In this article, the key advances in SnO₂ development are reviewed, including various deposition approaches and surface treatment strategies, to enhance the bulk and interface properties of SnO₂ for highly efficient and stable n-i-p PSCs. In addition, the general materials chemistry associated with SnO₂ along with the corresponding materials challenges and improvement strategies are discussed, focusing on defects, intrinsic properties, and impact on device characteristics. Finally, some SnO₂ implementations related to scalable processes and flexible devices are highlighted, and perspectives on the future development of efficient and stable large-scale perovskite solar modules are also provided.

Inorganic Photocatalytic Enhancement: Activated RhB Photodegradation by Surface Modification of SnO2 Nanocrystals with V2O5-like species

SnO₂ nanocrystals were prepared by precipitation in dodecylamine at 100 °C, then they were reacted with vanadium chloromethoxide in oleic acid at 250 °C. The resulting materials were heat-treated at various temperatures up to 650 °C for thermal stabilization, chemical purification and for studying the overall structural transformations. From the crossed use of various characterization techniques, it emerged that the as-prepared materials were constituted by cassiterite SnO₂ nanocrystals with a surface modified by isolated V(IV) oxide species. After heat-treatment at 400 °C, the SnO₂ nanocrystals were wrapped by layers composed of vanadium oxide (IV-V mixed oxidation state) and carbon residuals. After heating at 500 °C, only SnO₂ cassiterite nanocrystals were obtained, with a mean size of 2.8 nm and wrapped by only V₂O₅-like species. The samples heat-treated at 500 °C were tested as RhB photodegradation catalysts. At 10^-7 M concentration, all RhB was degraded within 1 h of reaction, at a much faster rate than all pure SnO₂ materials reported until now.