scholarly journals Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
I. Abdul Rahman ◽  
M. T. M. Ayob ◽  
S. Radiman

ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment.

2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


NANO ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. 1650129 ◽  
Author(s):  
Xinlin Liu ◽  
Yingying Qin ◽  
Mingjun Zhou ◽  
Yongsheng Yan

A unique CdS/Fe3O4/rGO composite photocatalyst is successfully synthesized by the microwave method. It displays promising photocatalytic activity towards the photo-degrading of tetracycline (TC) in aqueous solution, the degradation rate of TC is 69% with adding 0.1[Formula: see text]g CdS/Fe3O4/rGO photocatalyst into 20[Formula: see text]mg/L tetracycline for 2[Formula: see text]h under visible light irradiation. Furthermore, the mechanism was systematically investigated by active species trapping experiment. It can be known that [Formula: see text] the major active species in the photodegradation process and the possible process of charge transfer for CdS/Fe3O4/rGO was proposed based on the experimental results. The as-prepared samples were carefully evaluated by XRD, TEM, XPS, VSM, PL spectra, Raman spectrometer.


2012 ◽  
Vol 508 ◽  
pp. 259-262 ◽  
Author(s):  
Cheng Zhi Jiang ◽  
Rui Yang ◽  
Sen Bai ◽  
Xu Dong Lu

Pure BiVO4, single doped and co-doped BiVO4 have been prepared by chemical precipitation method and characterized by the techniques such as XRD and SEM/EDAX. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate pure BiVO4, single doped BiVO4 and co-doped BiVO4 photocatalytic activity. The results show that doping of single doped and co-doped significantly enhance the photocatalytic activity of BiVO4. When the 0.1%Gd3+ and 0.2%Sm co-doped, the BiVO4 degradation rate reaches 91%.


2013 ◽  
Vol 726-731 ◽  
pp. 429-434
Author(s):  
Wei Wang ◽  
Chun Hua Lu ◽  
Ya Ru Ni ◽  
Zhong Zi Xu

Anatase TiO2 nanosheets with different percentage of exposed high-reactive {001} facets were synthesized successfully. Besides the FESEM and TEM anslysis, XRD, Raman, and PL analysis were also conducted systematically to give a new insight on analyzing the as-prepared {001} facets dominated TiO2 photocatalysts. Photocatalytic activities of the photocatalysts were tested by the degradation of methylene blue (MB) aqueous solution under UV irradiation. The results indicated that there was an optimal percentage of the exposed {001} facets existed to give the highest photocatalytic activity of as-prepared TiO2 nanosheets. A possible mechanism for the enhanced photocatalytic activity of the {001} facets dominated anatase TiO2 was also proposed.


2021 ◽  
Author(s):  
Preethi Sudarsan ◽  
Vivek Seethapathy ◽  
Priya Ranganathan ◽  
Balakumar S ◽  
Suresh Babu Krishnamoorthy

Abstract Development of heterostructures is one of the constructive strategies for enhancing the photocatalytic activity. Here, novel CuFeO 2 -ZnO heterostructures with different weight percentage (CuFeO 2 = 0.5, 1, 5, 10%) were prepared by two-step precipitation-hydrothermal process. The structural confirmation was done by XRD and Raman analysis. The photocatalytic efficiency of the heterostructures was assessed by the degradation of methylene blue under sunlight. CuFeO 2 -ZnO heterostructures enhanced the photocatalytic performance compared to pure ZnO and CuFeO 2 . Among all, 5 wt % of CuFeO 2 on ZnO exhibited 100% degradation with 16 fold faster kinetics than ZnO. Time-resolved photoluminescent analysis revealed the increase in lifetime of charge carriers in the heterostructure. The band alignments of ZnO and CuFeO 2 , evaluated by Mott–Schottky revealed the existence of Type 1 heterostructures. Further, the heterostructures exhibited good recyclability. Thus, the present work demonstrates the use of p-type CuFeO 2 and n-type ZnO heterostructures as potential photocatalysts.


2011 ◽  
Vol 239-242 ◽  
pp. 1045-1048
Author(s):  
Xu Dong Lu ◽  
Cheng Zhi Jiang

Pure TiO2, Sm3+and Gd3+co-doping TiO2have been prepared by sol-gel method and characterized by the techniques such as XRD and SEM. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate Pure TiO2, Sm3+and Gd3+co-doping TiO2photocatalytic activity. The matrix distortion of TiO2increases after co-doping of Sm3+and Gd3+are clearly observed. The results show that co-doping of Sm3+and Gd3+inhibits the phase transformation of TiO2from anatase to rutile, decreases the diameter of TiO2nano-particles and significantly enhance the photocatalytic activity of TiO2. When the co-doped amounts for Sm3+and Gd3+are 0.1% and 0.2%, its degradation rate reaches 99%.


2011 ◽  
Vol 391-392 ◽  
pp. 1283-1286
Author(s):  
Cheng Zhi Jiang ◽  
Xu Dong Lu ◽  
Yan Qiu Tan ◽  
Sen Bai

Pure BiVO4, Sm doped BiVO4have been prepared by chemical precipitation method and characterized by the techniques such as XRD and SEM. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate pure BiVO4, Sm doped BiVO4photocatalytic activity. The results show that doping of Sm decreases the diameter of BiVO4 nano-particles and significantly enhance the photocatalytic activity of BiVO4. When the 0.2% Sm doped, the BiVO4degradation rate reaches 92.8%.


2020 ◽  
Vol 11 (3-2020) ◽  
pp. 145-151
Author(s):  
K. A. Pozhivina ◽  

In this article powdered composites of titanium dioxide and silica with high-developed surface(183–534 m2 / g), synthesized from industrial wastes, are considered as photocatalytic concrete additives. Their composition was studied, and the photocatalytic performance was evaluated by decomposition of the dye “Methylene blue” under UV-irradiation. The surfactant’s concentration at which the photocatalytic activity reaches its highest values was determined.


2021 ◽  
Vol 333 ◽  
pp. 11002
Author(s):  
Tippabust Eksangsri ◽  
Chaweewan Sapcharoenkun ◽  
Siripond Phromma

Titanium dioxide (TiO2) has been extensively studied as photo-catalyst for water treatment, air purification and antibacterial applications due to its challenging properties such as chemical stability, environmental friendly and strong photocatalytic activity. However, the limitation of TiO2 on its dependent to ultraviolet radiation for photocatalytic activity is still aroused. In this study, silver doped titanium dioxide (Ag-TiO2) was synthesized by wet-ball milling sol–gel method (WBMS). Ag-TiO2 molar ratio was varied from 0% to 10% to study the effect of silver content on the synthesized Ag-TiO2 characteristics and the ability to apply on antibacterial applications. The objective of this work was to find an optimal concentration of Ag in Ag-TiO2. Characterization of the particle size, morphology, and surface area of synthesized Ag-TiO2 were discussed by techniques of transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). Photocatalytic activity was investigated from degradation of methylene blue. Antibacterial activity was conducted by finding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under dark condition and under visible light. The results demonstrated that the doping of Ag inhibited crystal growth of Ag-TiO2. The smallest particle size and the highest surface area were obtained from 5% Ag-TiO2. Also, it was found that methylene blue degradation rate increased to the highest number of 1.62x10−3 min−1 when Ag concentration reached 5%, and methylene blue degradation rate reduced when Ag concentration was higher than 5%. The antibacterial activity of Ag-TiO2 was better than TiO2. The optimal concentration of 3-5% Ag-TiO2 was observed from the MIC and MBC tests.


2014 ◽  
Vol 699 ◽  
pp. 53-58
Author(s):  
Zatil Amali Che Ramli ◽  
Wan Nor Roslam Wan Isahak ◽  
Mohd Ambar Yarmo ◽  
Nilofar Asim

In this paper the photocatalytic activity of TiO2-PANi nanocomposites prepared using two differentIn-situpolymerization methods have been investigated. The same pressure, temperature, precursors, mole ratio, and solvent have been employed for preparation of nanocomposites. The synthesized nanocomposites were characterized by FESEM, XRD and FTIR. Results revealed the successful preparation of TiO2- PANI nanocomposites. TiO2-PANi nanocomposite synthesized using method 2 showed very well dispersed TiO2nanoparticles on the surface of PANi. There is no agglomeration of TiO2nanoparticles in PANi matrix. The photocatalytic activities of nanocomposites were evaluated by using photo degradation of Methylene Blue (MB) in aqueous solution under UV irradiation. These nanocomposites exhibit much higher photocatalytic activity compared with TiO2.


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