scholarly journals Comparative photocatalytic activity of sol–gel derived rare earth metal (La, Nd, Sm and Dy)-doped ZnO photocatalysts for degradation of dyes

RSC Advances ◽  
2018 ◽  
Vol 8 (31) ◽  
pp. 17582-17594 ◽  
Author(s):  
Umair Alam ◽  
Azam Khan ◽  
Danish Ali ◽  
Detlef Bahnemann ◽  
M. Muneer

In this study, we compared the photocatalytic activity of sol–gel derived rare earth metal (La, Nd, Sm and Dy)-doped ZnO photocatalysts by studying the degradation of MB and RhB under UV light irradiation.

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Baolin Xing ◽  
Changliang Shi ◽  
Chuanxiang Zhang ◽  
Guiyun Yi ◽  
Lunjian Chen ◽  
...  

Photocatalysts comprising nanosized TiO2particles on activated carbon (AC) were prepared by a sol-gel method. The TiO2/AC composites were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, nitrogen adsorption, scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X-ray (EDX). Their photocatalytic activities were studied through the degradation of Rhodamine B (RhB) in photocatalytic reactor at room temperature under ultraviolet (UV) light irradiation and the effect of loading cycles of TiO2on the structural properties and photocatalytic activity of TiO2/AC composites was also investigated. The results indicate that the anatase TiO2particles with a crystal size of 10–20 nm can be deposited homogeneously on the AC surface under calcination at 500°C. The loading cycle plays an important role in controlling the loading amount of TiO2and morphological structure and photocatalytic activity of TiO2/AC composites. The porosity parameters of these composite photocatalysts such as specific surface area and total pore volume decrease whereas the loading amount of TiO2increases. The TiO2/AC composite synthesized at 2 loading cycles exhibits a high photocatalytic activity in terms of the loading amount of TiO2and as high as 93.2% removal rate for RhB from the 400 mL solution at initial concentration of 2 × 10−5 mol/L under UV light irradiation.


2009 ◽  
Vol 620-622 ◽  
pp. 679-682 ◽  
Author(s):  
Dae Yong Shin ◽  
Kyung Nam Kim

Thin films of various composition in the system of TiO2•SiO2 have been fabricated by the sol-gel process using Si(OC2H5) and Ti(OC3H7i)4 as precursors. TiO2•SiO2 films were formed on the glass substrate by spin-coating technique and heated at 500°C for 1 h. The relationship between hydrophilicity, photocatalytic properties and self-cleaning property with SiO2 addition and UV light irradiation were investigated. Photocatalytic activity of TiO2•SiO2 films showed decomposition of ~97% of acetaldehyde in 2 h and a water contact angle of ~10°. TiO2•SiO2 films can have more hydrophilic activity and less photocatalytic activity by increasing of SiO2 addition. XPS measurements revealed that the amount of organic compounds adsorbed on the films decreased with the UV light irradiation and SiO2 addition, because of the increased of both OH group contents in films and decomposed organic contaminants of the films surface.


Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1622
Author(s):  
Xiao-Pin Guo ◽  
Peng Zang ◽  
Yong-Mei Li ◽  
Dong-Su Bi

2-methylisoborneol (2-MIB) is a common taste and odor compound caused by off-flavor secondary metabolites, which represents one of the greatest challenges for drinking water utilities worldwide. A TiO2-coated activated carbon (TiO2/PAC) has been synthesized using the sol-gel method. A new TiO2/PAC photocatalyst has been successfully employed in photodegradation of 2-MIB under UV light irradiation. In addition, the combined results of XRD, SEM-EDX, FTIR and UV-Vis suggested that the nano-TiO2 had been successfully loaded on the surface of PAC. Experimental results of 2-MIB removal indicated that the adsorption capacities of PAC for 2-MIB were higher than that of TiO2/PAC. However, in the natural organic matter (NOM) bearing water, the removal efficiency of 2-MIB by TiO2/PAC and PAC were 97.8% and 65.4%, respectively, under UV light irradiation. Moreover, it was shown that the presence of NOMs had a distinct effect on the removal of MIB by TiO2/PAC and PAC. In addition, a simplified equivalent background compound (SEBC) model could not only be used to describe the competitive adsorption of MIB and NOM, but also represent the photocatalytic process. In comparison to other related studies, there are a few novel composite photocatalysts that could efficiently and rapidly remove MIB by the combination of adsorption and photocatalysis.


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