Green Synthesis of Zinc Oxide-Graphene Oxide Composite via Ex Situ and In Situ Methods for the Photoassisted Removal of Congo Red Dye: A Comparative Study

作者：Asadullah, Aleena Aleena, Abbas Khan, Ubaid Ur Rahman, Muhammad Humayun, Ali Akbar, Amal Faleh Alanazi, M. Bououdina · 发表于：ACS Omega · 年份：2025 · DOI：10.1021/acsomega.5c02342 · 被引用次数：21 · 研究领域：Graphene and Nanomaterials Applications、Advanced Nanomaterials in Catalysis

High Resolution Image Download MS PowerPoint Slide Industrial chemical pollutants, such as Congo red (CR) dye, are released into water in large amounts, posing a serious threat to the ecosystem. To deal with this issue, we aimed to synthesize an environmentally friendly nanocatalyst, especially zinc oxide (ZnO) and in situ ZnO-decorated graphene oxide (I-ZnO@GO), using Aloe vera extract as a reducing agent, graphene oxide (GO) was synthesized by a modified hummer method, while ex situ ZnO-decorated-GO (E-ZnO@GO) was prepared via a simple coprecipitation method. These nanocomposites were then used for the photoassisted removal of Congo red dye from wastewater. The optical properties, chemical composition, morphology, thermal stability, and crystallinity of the synthesized nanocomposites were characterized by employing ultraviolet–visible spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), thermogravimetric analysis (TGA) with differential scanning calorimetry (DSC), and X-ray Diffraction (XRD) analysis. The photoassisted dye removal efficiency of the synthesized nanocomposites was assessed using batch processing methodology across multiple experimental parameters to eliminate CR dye from wastewater. Notably, I-ZnO@GO exhibited higher photocatalytic degradation of CR (84.78%) compared to ZnO (54.9%), GO (62.17%), and E-ZnO@GO (74.78%) after 100 min under identical e...