Visible‐light driven photodegradation of phenol over niobium oxide‐loaded fibrous silica titania composite catalyst

Abstract

BACKGROUND Heterogeneous photocatalysis has been demonstrated to be a promising alternative to treating emerging pollutants in wastewater. Phenol, an extremely toxic substance among existing pollutants, can cause long‐term unintended effects when improperly disposed. An effective measure to address this problem is to develop suitable heterojunctions. Among various photocatalyst, titanium dioxide (TiO2) appears to be an excellent photocatalyst in the degradation of organic pollutants. RESULTS Synthetization of well‐constructed heterojunction composite of niobium oxide (Nb2O5) and fibrous silica titania (FST) for enhanced photocatalytic degradation of phenol has been investigated. The photocatalytic performance demonstrated that 5 wt% Nb2O5 loaded on FST (5 Nb/FST) gave the maximum phenol degradation rate (1.70 × 10−2 mM min−1) of 10 mg L−1 phenol at pH 5 using 1000 mg L−1 catalyst within 180 min. Meanwhile, under the same conditions, 1 Nb/FST, FST, 10 Nb/FST and Nb2O5 only delivered 1.51 × 10−2, 1.30 × 10−2, 1.01 × 10−2 and 0.07 × 10−2 mM min−1, respectively. Further phenol photocatalytic degradation routes by 5 Nb/FST reveal that the main intermediates detected are hydroquinone, catechol, maleic, fumaric, and malonic acid. CONCLUSION In this work, 5 Nb2O5/FST composite, as an effective‐performance photocatalyst for phenol degradation, was well‐constructed. The advanced activity can primarily be attributed to the regulated Nb2O5 loading with FST and the effect of Nb/FST microsphere heterojunctions, synergistically. Besides, larger crystallite size, high impurity levels and Si‐O‐Nb and Nb–O–Ti bonds, offers excellent phenol degradation. © 2020 Society of Chemical Industry (SCI)

Response Surface Methodology: Photocatalytic Degradation Kinetics of Basic Blue 41 Dye Using Activated Carbon with TiO2

“…Consequently, activation of TiO 2 nanoparticles by the UV-light produced reactive species (OH), which facilitated the degradation of organics in the solution [ 12 , 33 ]. As shown in Figure 3 b, the degradability followed the first-order kinetics for irradiation time less than 60 min.…”

“…The positive sign represents the synergistic effect of the term on the response, whereas, the negative sign points out an antagonistic effect. In this view, the increasing order of the effect of the terms for the removal of colour follows AC > B 2 > AB > B > A > C, whereas that of the turbidity removal is AC > AB > B > C 2 > A > C. Also, the optimal values of the parameters are obtained by estimating the regression equation and the analysis of the surface response: Consequently, activation of TiO 2 nanoparticles by the UV-light produced reactive species (OH), which facilitated the degradation of organics in the solution [12,33]. As shown in Figure 3b, the degradability followed the first-order kinetics for irradiation time less than 60 min.…”

Adsorption and Photocatalytic Mineralization of Bromophenol Blue Dye with TiO2 Modified with Clinoptilolite/Activated Carbon

“…Notwithstanding, the dominating phase of the TiO 2 pattern in all the samples by the XRD peaks ( Figure 1) within the angle range of 2θ (5 • > 2θ > 70 • ) is anatase corresponding to the JCPDS Files No.21-1272 [33,34]. The peaks observed at 2θ values of 25 (Figure 1) by the broad bump of A-TiO 2 around 2θ = 25.28 • . Adding to this, the reflection peak in the A-TiO 2 of the anatase around 2θ = 25.67 • decreased, whereas the rutile peak at 2θ = 27.45 • (002) became sharper and stronger.…”

PVP‐assisted synthesis of P‐Bi4O5Br2/AgI heterojunction with enhanced photocatalytic activity for degradation of rhodamine B

“…9 Meanwhile, its photogenerated carriers are easy to recombine, reducing the photocatalytic performance. 10,11 Constructing heterojunctions could effectively constrain the recombination of carriers, boosting the photocatalytic performance of Bi 4 O 5 Br 2 by combining with another semiconductor (such as BiOBr, AgBr, g-C 3 N 4 , etc.). 12 For example, Chen et al reported that the AgBr/Bi 4 O 5 Br 2 Z-scheme heterojunction was prepared by hydrothermal combination and ion exchange method for nitrogen fixation reaction, which greatly suppressed the recombination of photo-generated carriers.…”