Enhanced photocatalytic degradation of methyl orange by coconut shell–derived biochar composites under visible LED light irradiation

Author(s):  
Yean Ling Pang ◽  
Zhi Xuan Law ◽  
Steven Lim ◽  
Yin Yin Chan ◽  
Siew Hoong Shuit ◽  
...  
2012 ◽  
Vol 512-515 ◽  
pp. 1677-1682 ◽  
Author(s):  
Fu Sheng Liu ◽  
Sheng Wang ◽  
Lian Lian Liu ◽  
Huan Du

In this paper, p-n coupled photocatalyst CoO/CdS/TiO2 was prepared by method of impregnation. The structure and optical properties of CdS/TiO2 and CoO/CdS/TiO2 were characterized by XRD, SEM, BET and UV–vis DRS. The photocatalytic activities of the photocatalysts were evaluated by photocatalytic degradation of methyl orange, and the effect of photocorrosion of CdS in CoO/CdS/TiO2 was investigated by analyzing the cadmium concentration in the supernate collected after photocatalytic reactions. The results showed that p-n coupled photocatalyst CoO/CdS/TiO2 not only showed higher efficiency in degradation of methyl orange than CdS/TiO2, but also exhibited resistance against cadmium leakage under light irradiation. The mechanism of the photocorrosion-delaying by p–n junction was also discussed.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1059
Author(s):  
Piangjai Peerakiatkhajohn ◽  
Teera Butburee ◽  
Jung-Hoon Sul ◽  
Supphasin Thaweesak ◽  
Jung-Ho Yun

ZnO and Aluminum doped ZnO nanoparticles (Al/ZnO NPs) were successfully synthesized by the sol-gel method. Together with the effect of calcination temperatures (200, 300 and 400 °C) and Al dosage (1%, 3%, 5% and 10%) on structural, morphological and optical properties of Al/ZnO NPs, their photocatalytic degradation of methyl orange (MO) dye was investigated. The calcination temperatures at 200, 300 and 400 °C in forming structure of ZnO NPs led to spherical nanoparticle, nanorod and nanoflake structures with a well-crystalline hexagonal wurtzite, respectively. The ZnO NPs calcined at 200 °C exhibited the highest specific surface area and light absorption property, leading to the MO removal efficiency of 80% after 4 h under the Ultraviolet (UV) light irradiation. The MO removal efficiency was approximately two times higher than the nanoparticles calcined at 400 °C. Furthermore, the 5% Al/ZnO NPs exhibited superior MO removal efficiency of 99% in only 40 min which was approximately 20 times enhancement in photocatalytic activity compared to pristine ZnO under the visible light irradiation. This high degradation performance was attributed to the extended light absorption, narrowed band gap and effective suppression of electron–hole recombination through an addition of Al metal.


2015 ◽  
Vol 33 (2) ◽  
pp. 456-464 ◽  
Author(s):  
Venkata Ramana Posa ◽  
Viswadevarayalu Annavaram ◽  
Janardhan Reddy Koduru ◽  
Varada Reddy Ammireddy ◽  
Adinarayana Reddy Somala

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