Visible-light-driven removal of mixed dye pollutants by a novel ZnO/CNT/GO ternary nanocomposite: Synergistic degradation of Congo red and methylene blue
Journal
Environmental Research
Journal Volume
283
Start Page
122156
ISSN
0013-9351
Date Issued
2025-10
Author(s)
Abstract
Photocatalysis offers a cost-effective solution for addressing industrial wastewater treatment, provided its efficiency is further enhanced. One effective strategy to achieve this is by expanding the light absorption range of photocatalysts through the incorporation of nanomaterial composites. In this work, we have devised a sustainable method to overcome the photocatalytic limitations facing nanostructured zinc oxide nanorods (ZnO NRs), by compositing it with multi-walled carbon nanotubes (CNT) decorated on graphene oxide (GO) nanosheets through a cost effective and easy ultrasonication method. The structural, morphological, electronic, and optical properties of the synthesized nanocomposites were confirmed through physicochemical analyses, and its photocatalytic performance is tested using individual and mixed dyes pollutants; i.e., Congo red (CR) and methylene blue (MB). BET and BJH analysis confirms an increase of surface area (11.19 m2/g) and porosity (25.12 nm) in ZnO/CNT/GO nanocomposite with an average pore volume of 0.0651 cc/g. The ZnO/CNT/GO composite shows significantly higher degradation rates (kCR = 0.0253 min−1 and kMB = 0.0978 min−1) compared to pure ZnO nanorods (kCR = 0.0149 min−1 and kMB = 0.0143 min−1) and ZnO/CNT binary composite (kCR = 0.0223 min−1 and kMB = 0.0227 min−1). The improved photocatalytic activity can be attributed to the material's strong visible light absorption, efficient charge carrier separation, extensive surface area, and the synergistic interaction between ZnO nanorods, CNTs, and GO. Additionally, scavenging tests are conducted to evaluate the role of the primary reactive species responsible for dye degradation. The ZnO/CNT/GO ternary photocatalyst maintained excellent stability after 3 cycles, highlighting its promise as a stable, highly efficient, and sustainable solution for wastewater treatment and water pollution mitigation.
Subjects
Adsorption process
Nanocomposite
Photocatalytic activity
Scavengers
Wastewater treatment
ZnO nanorods
Publisher
Elsevier BV
Type
journal article