Defect engineering of Nb2O5 nanoparticles is an approachable way to improve photocatalytic performance. TT-Nb2O5 nanoparticles were synthesized using the Pechini method followed by calcination, producing line defects in the crystalline structure and single-electron-trapped oxygen vacancies (SETOVs). The structural results demonstrate that TT-Nb2O5 calcined at 500 °C presents a superlattice orthorhombic structure with a specific surface area between 45 and 90 m2 g−1 and mesoporous network structure. Electronic properties analysis revealed that the TT-Nb2O5 nanoparticles synthesized by the Pechini method (NbPEG and NbEG) have different concentrations of SETOVs in their structure according to the polymerizing agent used in the synthesis, ethylene glycol and polyethylene glycol for NbEG and NbPEG, respectively. The unprecedented photochemical acetalization of glycerol into solketal, employing isopropyl alcohol instead of acetone, was described. The textural properties and the higher concentration of SETOVs significantly improved the photocatalytic performance of NbEG, allowing a synergistic dual catalytic behavior, where the electron accumulation process on the surface of the semiconductor took place, inducing proton generation, which improved the conversion of glycerol (47.8%) as well as the selectivity to solketal (69.8%).
Read full abstract