Impact of morphology on defect related properties and photocatalytic activity of tin oxide structures

Tin dioxide (SnO₂), with diverse morphological structures, stands out as a key candidate among wide bandgap semiconductors. This study examines how fabrication conditions influence the morphology of SnO₂ and the subsequent effects on its physical properties across different structures, such as highly crystalline SnO₂ Quantum Dots (QDs), cauliflower (CF), and kadam flower (KF). Optical and Raman studies confirm the presence of singly charged oxygen vacancies, leading to green emission in both QDs and CF. The increased surface area of QDs offers more active sites for dye adsorption, thereby enhancing photocatalytic activity. The oxygen vacancies in QDs and CF act as electron acceptors, reducing the surface recombination of electron-hole pairs. Comparative analysis shows that QDs are more effective catalysts for the photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes compared to flower-like SnO₂ microstructures. The rate of dye photodegradation is slower under solar light than under UV light.