Multilevel characterization of SnO2 nanostructures toward enhanced photocatalytic activity

Abstract

Abstract: Recent studies have explored SnO2 nanostructures as photo/electrocatalysts substitutes for TiO2 in environmental remediation and energy applications, due to this material sustainability and promising photo/electrocatalytic properties. This surge in interest is driving research endeavors aimed at unraveling the structure–function relationship, which remains not yet fully understood. Here, we present a multilevel characterization of SnO2 nanostructures synthesized by colloidal approaches into either spherical or rod-like shape, through established and low-cost synthetic hydrothermal and precipitation methods. We carefully investigate the synthesized SnO2 nanostructures via a multidisciplinary approach encompassing structural, textural, chemical, and optical characterization tools, unveiling and comparing their distinctive physical–chemical properties. Furthermore, the synthesized materials are assessed in the photocatalytic decolorization of methylene blue dye as a model compound, using commercial TiO2 P25 as a reference. The results highlight that the performance of the material derives from the combination of effects originating from the structure, electronic, and surface properties. Therefore, a multilevel characterization approach can pave the way to decipher which properties at the atomic or microscopic or macroscopic scale, originating from the specific synthesis method and conditions, influence the photocatalytic performance of materials. Impact statement: This manuscript presents a multidisciplinary approach to investigate colloidal SnO2 nanostructures prepared by both hydrothermal and precipitation approaches, with tailored morphology and size, and the relationship among electronic properties and surface characteristics, affecting the materials function as photocatalysts. Although significant literature already exists on SnO2 nanostructures, there is a burgeoning interest in this material as (photo/electro) catalysts due to its sustainability and remarkable photo/electrocatalytic properties. This surge in interest is driving research endeavors aimed at unraveling the intricacies of the structure–function relationship, which remains not yet fully understood. Valuable knowledge of the distinct physical-chemical properties of synthesized SnO2 NPs have been gained by integrating different characterization tools, currently available for investigation of photo(electro)catalyst semiconductors. Thanks to a multilevel approach, it has been highlighted how synthesis methodologies, NP structure, electronic and surface properties, and confirmed that their deliberate manipulation can enhance material (photo)catalytic performance. The manuscript delves into the realms of materials science, engineering, and chemistry, aiming to unravel crucial aspects that bridge materials to design and function.