Effect of synthesis parameters on the structural characteristics and photocatalytic activity of ZnO

2012 ◽  
Vol 136 (2-3) ◽  
pp. 505-511 ◽  
Author(s):  
Tania R. Giraldi ◽  
Georgia V.F. Santos ◽  
Vagner R. de Mendonca ◽  
Caue Ribeiro ◽  
Ingrid T. Weber
Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1873
Author(s):  
Petronela Pascariu ◽  
Niculae Olaru ◽  
Aurelian Rotaru ◽  
Anton Airinei

A new type of material based on carbon/ZnO nanostructures that possesses both adsorption and photocatalytic properties was obtained in three stages: cellulose acetate butyrate (CAB) microfiber mats prepared by the electrospinning method, ZnO nanostructures growth by dipping and hydrothermal methods, and finally thermal calcination at 600 °C in N2 for 30 min. X-ray diffraction (XRD) confirmed the structural characteristics. It was found that ZnO possesses a hexagonal wurtzite crystalline structure. The ZnO nanocrystals with star-like and nanorod shapes were evidenced by scanning electron microscopy (SEM) measurements. A significant decrease in Eg value was found for carbon/ZnO hybrid materials (2.51 eV) as compared to ZnO nanostructures (3.21 eV). The photocatalytic activity was evaluated by studying the degradation of three dyes, Methylene Blue (MB), Rhodamine B (RhB) and Congo Red (CR) under visible-light irradiation. Therefore, the maximum color removal efficiency (both adsorption and photocatalytic processes) was: 97.97% of MB (C0 = 10 mg/L), 98.34% of RhB (C0 = 5 mg/L), and 91.93% of CR (C0 = 10 mg/L). Moreover, the value of the rate constant (k) was found to be 0.29 × 10−2 min−1. The novelty of this study relies on obtaining new photocatalysts based on carbon/ZnO using cheap and accessible raw materials, and low-cost preparation techniques.


2019 ◽  
Vol 91 (3) ◽  
pp. 539-551 ◽  
Author(s):  
Ahmed Mudhafar Mohammed ◽  
Michael Sebek ◽  
Carsten Kreyenschulte ◽  
Henrik Lund ◽  
Jabor Rabeah ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Nora S. Portillo-Vélez ◽  
Monserrat Bizarro

There is an increasing interest on the application of ZnO nanorods in photocatalysis and many growth methods have been applied, in particular the spray pyrolysis technique which is attractive for large scale production. However it is interesting to know if the nanorod morphology is the best considering its photocatalytic activity, stability, and cost effectiveness compared to a nonoriented growth. In this work we present a systematic study of the effect of the precursor solution (type of salt, solvent, and concentration) on the morphology of sprayed ZnO films to obtain nanoflakes and nanorods without the use of surfactants or catalysts. The surface properties and structural characteristics of these types of films were investigated to elucidate which morphology is more favorable for photocatalytic applications. Wettability and photocatalytic experiments were carried out in the same conditions. After UV irradiation both morphologies became hydrophilic and achieved a dye discoloration efficiency higher than 90%; however, the nanoflake morphology provided the highest photocatalytic performance (99% dye discoloration) and stability and the lowest energy consumption during the synthesis process. The surface-to-volume ratio revealed that the nanoflake morphology is more adequate for photocatalytic water treatment applications and that the thin nanorods should be preferred over the large ones.


2021 ◽  
Vol 10 (4) ◽  
pp. xx-xx
Author(s):  
Hoa Nguyen Thi ◽  
Tien Nguyen Trung ◽  
Phong Le Hong ◽  
Tai Vu Van ◽  
Hung Nguyen Van ◽  
...  

In this research, Ag-Ag3PO4/Cellulose aerogel composite was synthesized using hydrothermal reduction and freeze-drying methods. By combining the photocatalytic activity of the semiconductor Ag-Ag3PO4 and cellulose aerogel synthesized from agricultural waste sources, the synthesized Ag-Ag3PO4/Cellulose aerogel composite has overcome the disadvantages of pure Ag3PO4 and significantly improved the photocatalytic activity. Structural characteristics, morphology, surface area of the materials were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption and UV–vis diffuse reflectance spectroscopy (UV-vis DRS) methods. From the obtained results, composite has narrow bandgap energy (2.275 eV) and excellent catalytic performance in the photodegradation of dye pollutants (99% MB and 77% RY 145 degraded after 4 h, and only a minor change in the efficiency observed after four consecutive tests). It  demonstrates the development of new catalysts made from agricultural waste sources that show high stability, ease of fabrication and can operate in natural light for environmental remediation.


2016 ◽  
Vol 12 (1) ◽  
pp. 45-61 ◽  
Author(s):  
Mahdi Shahrezaei ◽  
Sajjad Habibzadeh ◽  
Ali Akbar Babaluo ◽  
Hossein Hosseinkhani ◽  
Mohammad Haghighi ◽  
...  

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