Potential of Nb2O5 nanofibers in photocatalytic degradation of organic pollutants

Abstract

Due to the pollution caused by different organic pollutants, various photocatalytic nanomaterials for environmental remediation have been promoted. In this study, Nb 2 O 5 nano bers were obtained by electrospinning technique, presenting controlled crystallinity and high speci c surface area to improve the photoactivity response. The structural characterization indicated Nb 2 O 5 nano bres with orthorhombic phase formation, and the photoluminescence measurements showed different energy levels contributing to the electronic transition events. The nano bers with a bandgap up to 3.6 eV were applied to photocatalysis of dyes [Rhodamine B (RhB) or Methylene Blue (MB)], and Prozac®, listed as an emergent pollutant. In the optimized condition (pH = 9), the RhB and MB photocatalysis was 59% and 93% more e cient than photolysis due to ζ = − 50 ± 5 mV for EtOH_550 sample that increased the interaction with MB (cationic) compared to RhB unprotonated (pKa = 3.7). Therefore, Prozac® (pKa = 10.7) was selected due to protonated form at pH = 9 and showed 68% ±1 adsorption in 30 min for EtOH_550. The Prozac® photocatalytic degradation under UV light irradiation was up to 17% higher than the photolytic degradation. The formation of hydroxyl radicals in the photocatalytic system (EtOH_550) was proven by the Coumarine probe assay, corroborating with the greater amount of α-[2-(Methylamino)ethyl]benzylalcohol (MAEB), a by-product obtained after Prozac® oxidation. Additionally, the material achieved speci c catalytic activity for the different organic compounds (RhB, MB, or Prozac®), showing that only using dyes may not be ideal to conclude the great material applicability in environmental remediation studies. Therefore, Nb 2 O 5 nano bers were e cient for the degradation of three different pollutants under UV light, proving to be a viable alternative for environmental remediation.

Preparation and Application of Nb2O5 Nanofibers in CO2 Photoconversion

“…Recent literature [18,19] has focused on producing niobium-based fibers for photodegradation of the organic pollutants, using polyvinylpyrrolidone (PVP) as a polymeric precursor. The results indicate that the pseudohexagonal TT-Nb 2 O 5 phase showed greater efficiency, more than 62% degradation.…”

A Transparent, High-Strength, and Recyclable Core–Shell Structured Wood Hydrogel Integrated with Carbon Dots for Photodegradation of Rhodamine B

“…It is reported that TC has p K a1 = 3 and p K a2 = 9, suggesting that TC presents in the form of zwitterions at 3 < pH < 9 . At pH = 7, both surface charges of PAA and Bi-N-CDs/BiOBr are negative (Figure S6); hence, electrostatic repulsion may be the main interaction between Bi-N-CDs/BiOBr@TW and zwitterionic TC and RhB, thus restraining the removal of contaminants. ,, Nevertheless, positively charged CV (p K a = 9.4) and MB (cationic) are readily absorbed onto Bi-N-CDs/BiOBr@TW because of electrostatic attraction, thus facilitating elimination reactions. , Impressively, the lower removal efficiency of MB compared to CV may be caused by the weak photosensitivity of MB due to its maximum absorption at 664 nm (Figure S7). TC, as an achromatic molecule, shows only 46.3% removal rate after 300 min, which is due to the absence of a photosensitization process, so it is not susceptible to photodegradation .…”

“…39,40,45 Nevertheless, positively charged CV (pK a = 9.4) and MB (cationic) are readily absorbed onto Bi-N-CDs/BiOBr@TW because of electrostatic attraction, thus facilitating elimination reactions. 46,47 Impressively, the lower removal efficiency of MB compared to CV may be caused by the weak photosensitivity of MB due to its maximum absorption at 664 nm (Figure S7). TC, as an achromatic molecule, shows only 46.3% removal rate after 300 min, which is due to the absence of a photosensitization process, so it is not susceptible to photodegradation.…”

Alumina Coatings Containing Niobium Pentoxide Polymorphs Prepared by Plasma Electrolytic Oxidation of Aluminum

“…In the present case, we cannot assure that this was the cause of the formation of a mixture of crystalline T‐Nb 2 O 5 and H‐Nb 2 O 5 . Nevertheless, several studies connect the presence of T‐Nb 2 O 5 to an increase in photocatalytic activity, depicting results for RhB, [ 59 ] methyl blue (MB), [ 58 ] methyl orange (MO), [ 64 ] and fluoxetine (FLX) [ 65 ] above 40% of the photodegradation.…”