scholarly journals Combination of rGO/S, N/TiO2 for the Enhancement of Visible Light-Driven Toluene Photocatalytic Degradation

Author(s):  
Birgitta Narindri Rara Winayu ◽  
Wan-Hua Mao ◽  
Hsin Chu

Abstract Toluene is one type of common volatile organic compound (VOC) that is produced by daily products and is harmful to human health. Therefore, the degradation of toluene is critical to improving indoor air quality value. Photocatalytic degradation is considered an efficient and safe method to convert toluene into water and carbon dioxide without the formation of a secondary pollutant. Performance improvement of TiO2, a typically applied photocatalyst, has advantages in light absorption and electron transfer process. In this study, the TiO2 improvement was carried out by the doping of sulfur and nitrogen (S, N) elements along with various reduced graphene oxide (rGO). The composition of 0.1wt%rGO/S0.05N0.1TiO2 performed higher photocatalytic degradation of toluene due to the elevation of specific surface area, formation of oxygen-containing functional group, and chemical defect structure. However, a higher amount of rGO addition creates the shielding effect and inhibits the light penetration. Moreover, the relative humidity and applied temperature influence the photocatalytic activity through the competitive adsorption or increase the collisions frequency, respectively. During the photocatalytic degradation using 0.1wt%rGO/S0.05N0.1TiO2, toluene will be converted into benzyl alcohol, benzaldehyde, benzoic acid, water, and carbon dioxide.

2015 ◽  
Vol 2 (1) ◽  
pp. 70 ◽  
Author(s):  
Feng-Chyi Duh

This study investigated transient effects on the air quality of parked cars and moving cars with and without operating air conditioning. Carbon dioxide, carbon monoxide, volatile organic compounds, and formaldehyde concentrations were measured for comparative analysis. The results showed that simply changing the air conditioning system from internal circulation to external circulation to introduce air from outside reduces carbon dioxide concentrations by more than 50%, volatile organic compound concentrations by more than 77%, and the heat index from 0.1℃/min to less than 0.05 ℃/min. In order to conserve energy and improve car indoor air quality, this study can serve as a reference on healthy car environments.


2019 ◽  
Vol 11 (9) ◽  
pp. 1263-1270 ◽  
Author(s):  
Zhanguo Li ◽  
Chao Shi ◽  
Lijuan Wang ◽  
Lijing Sun ◽  
Qiang Sun

Photocatalytic nanocomposites of titanium dioxide (TiO2) were prepared by hydrothermal method. Reduced graphene oxide (RGO) was applied to prepare various TiO2 composites of doped nanoparticles by using NH4Cl and FeCl3 as sources. The structure and morphology of these composites showed that TiO2 was loaded on surface of RGO. Meanwhile, the agglomeration of TiO2 decreased and the dispersion became uniform for doped materials. Under ultraviolet (UV) light irradiation, the photocatalytic degradation of volatile organic compounds (VOC) by RGO/TiO2 composites with codoping of N and Fe reached to 90.5%. The photocatalytic degradation was higher than RGO/TiO2 composites and pure TiO2 by 1.8 and 5.9 times, respectively. The role of co-doping composites may have a possible mechanism for toluene under UV light irradiation. The enhanced photocatalytic properties were attributed to N and Fe doping which generated intermediate energy level, extended absorption and decreased band gap of UV light.


2019 ◽  
Vol 11 (9) ◽  
pp. 1263-1270
Author(s):  
Zhanguo Li ◽  
Chao Shi ◽  
Lijuan Wang ◽  
Lijing Sun ◽  
Qiang Sun

Photocatalytic nanocomposites of titanium dioxide (TiO2) were prepared by hydrothermal method. Reduced graphene oxide (RGO) was applied to prepare various TiO2 composites of doped nanoparticles by using NH4Cl and FeCl3 as sources. The structure and morphology of these composites showed that TiO2 was loaded on surface of RGO. Meanwhile, the agglomeration of TiO2 decreased and the dispersion became uniform for doped materials. Under ultraviolet (UV) light irradiation, the photocatalytic degradation of volatile organic compounds (VOC) by RGO/TiO2 composites with codoping of N and Fe reached to 90.5%. The photocatalytic degradation was higher than RGO/TiO2 composites and pure TiO2 by 1.8 and 5.9 times, respectively. The role of co-doping composites may have a possible mechanism for toluene under UV light irradiation. The enhanced photocatalytic properties were attributed to N and Fe doping which generated intermediate energy level, extended absorption and decreased band gap of UV light.


2014 ◽  
Vol 07 (02) ◽  
pp. 1450013 ◽  
Author(s):  
Jie Zhu ◽  
Wanhong He ◽  
Lu Zhang ◽  
Xu Xiang ◽  
Zhiwei Li

A new protocol was developed to obtain a composite photocatalyst by incorporating indium to ZnO and subsequently assembling it with reduced graphene oxide (RGO) sheets. The incorporation of indium led to lattice distortion of ZnO and introduction of defect levels. The hybridization with RGO could improve the electron transport and extend the lifetime of photo-generated carriers, leading to enhanced activity for dye degradation driven by visible light. The photocatalytic activity appeared to be dependent on the relative quantity of RGO. The optimized quantity resulted in the highest activity due to the dual role of electron shuttle and "shielding effect" of RGO. In addition, the composite photocatalyst exhibited excellent repeatable use performance, suggestive of its high stability. This study proposed a promising strategy to construct photocatalysts by rational bandgap engineering and tunable composite technology.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 471
Author(s):  
Ye Qin ◽  
Fei Qi ◽  
Zhiping Wang ◽  
Xianbao Cheng ◽  
Botao Li ◽  
...  

Volatile organic compounds (VOCs) in wood furniture are an important factor that affects indoor air quality. In this study, radiata pine (Pinus radiata D. Don) was treated with sodium bicarbonate and ozone aqueous solution to reduce the VOC contents without sacrificing mechanical properties. The VOCs of radiata pine were identified by gas chromatography-mass spectrometry (GC-MS), and the functional group changes of wood samples were characterized by Fourier-transform infrared spectroscopy (FTIR). The results showed that the main VOCs of radiata pine include alkenes, aldehydes, and esters. The sodium bicarbonate and ozone treatments almost eliminated the VOC contents of radiata pine. The two treatments mentioned above had little effect on compressive strength and surface color of radiata pine.


Author(s):  
Manpreet Singh ◽  
Athulya S. Palakkal ◽  
Renjith S. Pillai ◽  
Subhadip Neogi

Metal-organic frameworks (MOFs) have surfaced as incipient class of multifaceted materials for selective carbon dioxide (CO2) adsorption and luminescent detection of assorted classes of lethal organo-aromatics, where functional group assisted...


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