TY - JOUR
T1 - Ultrasound-assisted heterogeneous degradation of tetracycline over flower-like rGO/CdWO4 hierarchical structures as robust solar-light-responsive photocatalysts
T2 - Optimization, kinetics, and mechanism
AU - Ghoreishian, Seyed Majid
AU - Raju, G. Seeta Rama
AU - Pavitra, E.
AU - Kwak, Cheol Hwan
AU - Han, Young Kyu
AU - Huh, Yun Suk
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/9/30
Y1 - 2019/9/30
N2 - Novel hybrid decontamination processes based on visible-light-responsive photocatalysts (VLPHS) have recently become a focus of environmental research. In this study, the sonophotocatalytic degradation of the antibiotic tetracycline (TC) using a binary rGO/CdWO4 composite under simulated visible-light irradiation was demonstrated for the first time. Structural characterization confirmed that flower-like CdWO4 particles with a wolframite phase structure were successfully immobilized on the surface of the graphene oxide (GO). Subsequently, reduced GO/CdWO4 (rGO/CdWO4) VLPHS were prepared via the facile photocatalytic reduction of GO/CdWO4. A Box-Behnken design based on response surface methodology (RSM) was employed to determine the maximum efficiency of sonophotocatalytic degradation by optimizing the process parameters (pH, initial TC concentration, treatment time, and catalyst dosage). The high determination coefficients (R2 = 0.9818 and adjusted-R2 = 0.9636) indicated that the experimental values fitted the proposed RSM model well. Compared with CdWO4, rGO/CdWO4 VLPHS exhibited significant photoelectrochemical (PEC) performance, superior sonophotocatalytic activity, and mineralization efficiency. The enhanced catalytic activity was mainly due to the larger optical adsorption range, greater photo-induced charge carrier transfer, and higher surface area. In addition, rGO/CdWO4 exhibited a catalytic activity that was 1.5 and 3 times higher than that of commercial nano–ZnO and –TiO2, respectively. The kinetic analysis indicated that the degradation rate of TC follows the Langmuir–Hinshelwood kinetic model. The possible photocatalytic mechanism behind the degradation of TC by rGO/CdWO4 was also tentatively proposed. This study provides a simple and scalable pathway to produce highly efficient rGO-based VLPHS for photocatalytic and PEC applications.
AB - Novel hybrid decontamination processes based on visible-light-responsive photocatalysts (VLPHS) have recently become a focus of environmental research. In this study, the sonophotocatalytic degradation of the antibiotic tetracycline (TC) using a binary rGO/CdWO4 composite under simulated visible-light irradiation was demonstrated for the first time. Structural characterization confirmed that flower-like CdWO4 particles with a wolframite phase structure were successfully immobilized on the surface of the graphene oxide (GO). Subsequently, reduced GO/CdWO4 (rGO/CdWO4) VLPHS were prepared via the facile photocatalytic reduction of GO/CdWO4. A Box-Behnken design based on response surface methodology (RSM) was employed to determine the maximum efficiency of sonophotocatalytic degradation by optimizing the process parameters (pH, initial TC concentration, treatment time, and catalyst dosage). The high determination coefficients (R2 = 0.9818 and adjusted-R2 = 0.9636) indicated that the experimental values fitted the proposed RSM model well. Compared with CdWO4, rGO/CdWO4 VLPHS exhibited significant photoelectrochemical (PEC) performance, superior sonophotocatalytic activity, and mineralization efficiency. The enhanced catalytic activity was mainly due to the larger optical adsorption range, greater photo-induced charge carrier transfer, and higher surface area. In addition, rGO/CdWO4 exhibited a catalytic activity that was 1.5 and 3 times higher than that of commercial nano–ZnO and –TiO2, respectively. The kinetic analysis indicated that the degradation rate of TC follows the Langmuir–Hinshelwood kinetic model. The possible photocatalytic mechanism behind the degradation of TC by rGO/CdWO4 was also tentatively proposed. This study provides a simple and scalable pathway to produce highly efficient rGO-based VLPHS for photocatalytic and PEC applications.
KW - Langmuir–Hinshelwood
KW - Photoelectrochemistry
KW - Response surface methodology
KW - Sonophotocatalysis
KW - Tetracycline
KW - rGO/CdWO
UR - http://www.scopus.com/inward/record.url?scp=85067039074&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2019.05.299
DO - 10.1016/j.apsusc.2019.05.299
M3 - Article
AN - SCOPUS:85067039074
SN - 0169-4332
VL - 489
SP - 110
EP - 122
JO - Applied Surface Science
JF - Applied Surface Science
ER -