Oman Zuas; Harry Budiman; Nuryatini Hamim
Abstract
The ZnO nanoparticles (ZnO NPs) were synthesized by co-precipitating method followed by calcining at 500 o C for 4 h. The characterization data show that the synthesized ZnO NPs were present in hexagonal wurtzite structure and space group P63mc with high purity and good crystalline nature. The synthesized ...
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The ZnO nanoparticles (ZnO NPs) were synthesized by co-precipitating method followed by calcining at 500 o C for 4 h. The characterization data show that the synthesized ZnO NPs were present in hexagonal wurtzite structure and space group P63mc with high purity and good crystalline nature. The synthesized ZnO NPs were tested for decolorization of congo red (CR) dye under microwave irradiation using microwave induced catalytic (MIC) method. The investigation results showed that the microwave induced ZnO NPs process could effectively decolorize the CR dye with the efficiency approaches 90.63% in a short contact time under given condition of 10 mg/l CR dye, 300 watt of microwave power, 3 min of contact time, and 3 g/l of catalyst dosage. Since the microwave-induced catalytic process in this study is noticeable, the microwave technology coupled with ZnO NPs as catalyst may have synergistic effects on the decolorization of CR dye giving high degradation ratio in short reaction time. Therefore, the microwave technology can be used as an alternative option to enhance the catalytic activity of metal nanoparticles dealing with removal of various industrial dyes containing wastewater.
Surender Duhan; B.S. Dehiya;Vijay Tomer
Abstract
Sol–gel chemistry has recently attracted a large attention with a view of preparation of silver-silica nano-composites for photo-catalytic applications. This method of synthesis allows glassy materials to be prepared at a much lower temperature than the traditional melt-glass techniques. Moreover, ...
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Sol–gel chemistry has recently attracted a large attention with a view of preparation of silver-silica nano-composites for photo-catalytic applications. This method of synthesis allows glassy materials to be prepared at a much lower temperature than the traditional melt-glass techniques. Moreover, it enables higher doping concentrations and a more uniform distribution of silver in the glass host matrix to be achieved. This method produces large quantities of amorphous gels that are thermal treated in air at the temperature of 500°C for one hour. The silver-silica samples were investigated through X-ray diffraction (XRD for the determination of their microstructure, phase and compositions. It is found that the microstructure depends closely on the solution pH and the extent of silver-doping. MB dye degradation by undoped and Ag doped SiO2 was studied under UV and Visible light irradiation. The results are intriguing as the doping by Ag produces opposite effects on photocatalytic degradation rates under the two conditions.