Cost-effective efficient materials for dye degradation using non-aqueous sol-gel route
Yogendra Yadawa1, Divanshu Jha2, Nitesh Joshi2
1Department of Chemical Engineering & Biochemical Engineering, Rajiv Gandhi Institute of Petroleum Technology, Jais, 229304, India. pms19002@rgipt.ac.in.
Environmental Science and Pollution Research International
|November 29, 2023
Summary
Pure zinc oxide (ZnO) nanoparticles exhibit superior photocatalytic degradation of Rhodamine 6G dye under visible light. Doping ZnO with magnesium (Mg) or sulfur (S) decreased degradation efficiency, contrary to expectations for enhanced photocatalysis.
Area of Science:
- Materials Science
- Nanotechnology
- Photocatalysis
Background:
- Zinc oxide (ZnO) nanoparticles are widely studied for photocatalytic applications.
- Doping is a common strategy to enhance the properties of semiconductor nanoparticles.
- Understanding the effect of doping on ZnO's photocatalytic activity is crucial for developing efficient catalysts.
Purpose of the Study:
- To synthesize pure ZnO, Mg-doped ZnO, and S-doped ZnO nanoparticles using a non-aqueous sol-gel method.
- To characterize the synthesized nanoparticles using various analytical techniques.
- To evaluate the photocatalytic degradation of Rhodamine 6G dye using the synthesized nanoparticles under visible light.
Main Methods:
- Non-aqueous sol-gel synthesis of ZnO, Mg-ZnO, and S-ZnO nanoparticles.
- Characterization using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray spectroscopy (EDX), Fourier-Transform Infrared Spectroscopy (FTIR), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis-DRS), X-ray Photoelectron Spectroscopy (XPS), Photoluminescence (PL), and Brunauer-Emmett-Teller (BET) surface area analysis.
- Photocatalytic degradation experiments using Rhodamine 6G dye under visible light-emitting diode (Vis-LED) irradiation.
Main Results:
- Mg-ZnO and S-ZnO showed c-axis compression and smaller crystallite sizes compared to pure ZnO.
- The optical band gaps of Mg-ZnO and S-ZnO were lower (2.93 eV and 2.32 eV) than pure ZnO (3.05 eV).
- Pure ZnO nanoparticles demonstrated the highest photocatalytic degradation rate constant (0.00344 min⁻¹) for Rhodamine 6G, outperforming Mg-ZnO (0.00104 min⁻¹) and S-ZnO (0.00108 min⁻¹).
Conclusions:
- Pure ZnO nanoparticles exhibit superior photocatalytic activity for Rhodamine 6G degradation under visible light compared to Mg- and S-doped ZnO.
- The enhanced performance of pure ZnO is attributed to its superior surface area (18.30 m²/g) and effective electron-hole separation.
- Doping with Mg and S did not enhance, but rather decreased, the visible light photocatalytic efficiency in this study.
