The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Mohammed A. Gondal - One of the best experts on this subject based on the ideXlab platform.
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Laser-induced removal of a dye C.I. Acid Red 87 using n-type WO3 Semiconductor Catalyst.
Journal of hazardous materials, 2009Co-Authors: Mohammad Qamar, Mohammed A. Gondal, K. Hayat, Zain H. Yamani, Khalid AlhooshaniAbstract:Water contamination by organic substances such as dyes is of great concern worldwide due to their utilization in many industrial processes and environmental concerns. To cater the needs for waste water treatment polluted with organic dyes, laser-induced photocatalytic process was investigated for removal of a dye derivative namely Acid Red 87 using n-type WO3 Semiconductor Catalyst. The degradation was investigated in aqueous suspensions of tungsten oxide under different experimental conditions using laser instead of conventional UV lamp as an irradiation source. The degradation process was monitored by measuring the change in dye concentration as a function of laser irradiation time by employing UV spectroscopic analysis. The degradation of dye was studied by varying different parameters such as laser energy, reaction pH, substrate concentration, Catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H2O2), and potassium bromate (KBrO3). The degradation rates were found to be strongly dependent on all the above-mentioned parameters. Our experimental results revealed that the dye degradation process was very fast (within few minutes) under laser irradiation as compared to conventional setups using broad spectral lamps (hours or days) and this laser-induced photocatalytic degradation method could be an effective means to eliminate the pollutants present in liquid phase. The experience gained through this study could be beneficial for treatment of waste water contaminated with organic dyes and other organic pollutants.
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Efficient removal of phenol from water using Fe2O3 Semiconductor Catalyst under UV laser irradiation
Journal of environmental science and health. Part A Toxic hazardous substances & environmental engineering, 2009Co-Authors: Mohammed A. Gondal, Mohammad N. Sayeed, Zain H. Yamani, Abdul Rahman Al-arfajAbstract:Efficient removal of phenol was carried out using laser induced photocatalyis process in the presence of Fe2O3 Semiconductor Catalysts, and under UV laser irradiation. Parametric dependence of the removal process was investigated carefully by variation of laser irradiation time, laser energy, and concentration of the Catalysts. pH measurements were also carried out to understand the photocatalytic process for removal of phenol. Maximum phenol removal achieved in this process was more than 90% during 1 hour of laser irradiation. This is considered highly efficient as compared to conventional setups using lamps. Reaction kinetics for the removal of phenol was also studied, and a reaction rate of 0.017 min− 1 was estimated, following first order kinetics.
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Rapid disinfection of E-Coliform contaminated water using WO3 Semiconductor Catalyst by laser-induced photo-catalytic process
Journal of Environmental Science and Health - Part A Toxic Hazardous Substances and Environmental Engineering, 2008Co-Authors: Mohammed A. Gondal, Amjad . KhalilAbstract:Laser-induced photo-catalysis process using WO(3) Semiconductor Catalyst was applied for the study of disinfection effectiveness of E-coliform-contaminated water. For this purpose, wastewater polluted with E-coliform bacteria was exposed to 355 nm UV radiations generated by third harmonic of Nd: YAG laser in special glass cell with and without WO(3) Catalyst. E-Coliform quantification was performed by direct plating method to obtain the efficiency of each disinfection treatment. The dependence of disinfection process on laser irradiation energy, amount of Catalyst and duration of laser irradiation was also investigated. The disinfection with WO(3) was quite efficient inactivating E-coliforms. For inactivation of E-coliforms, less than 8 minutes' laser irradiation was required, so that, the treated water complies with the microbial standards for drinking water. This study opens the possibility of application of this simple method in rural areas of developing countries using solar radiation.
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Laser-enhanced photocatalytic degradation of organic pollutants from water using ZnO Semiconductor Catalyst.
Journal of environmental science and health. Part A Toxic hazardous substances & environmental engineering, 2007Co-Authors: Mohammed A. Gondal, Mohammad N. SayeedAbstract:Wastewater contaminated with organic pollutants creates serious environmental problems. Laser induced photocatalysis has been investigated for removal of organic pollutant like phenol from water. The important mechanism for degradation of phenol by UV laser irradiation is redox reactions triggered by Semiconductor Catalyst in presence of water. In this study the potential of a ZnO Semiconductor Catalyst has been explored as an effective Catalyst for the photodegradation of phenol using a Nd:YAG laser-emitting at 355 nm in UV-radiation in a batch reactor. The influences of different parameters such as Catalyst concentration, UV-radiation intensity, and pH on the extent of photo degradation have been investigated. Overall degradation of phenol achieved was 70% after 60 minutes of laser irradiation of 100 ppm phenol solution in water. The reaction rate constant fit a first-order reaction model for phenol degradation and was estimated as 0.0088 min− 1. This study proved that laser induced photocatalytic remov...
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Laser enhanced photo-catalytic removal of phenol from water using p-type NiO Semiconductor Catalyst.
Journal of hazardous materials, 2007Co-Authors: Mohammed A. Gondal, Mohammad N. Sayeed, Zaki S. SeddigiAbstract:Abstract Phenol is a carcinogen to humans and is a serious health concern, even at low concentrations. The efficient removal of phenol inside waste water is highly desirable. Laser induced photo-catalysis has been applied for removal of phenol from waste water using p-type NiO Semiconductor Catalyst for the first time. The characteristics of phenol removal using laser induced photo-catalytic process were investigated. The dependence of phenol removal on laser energy (100–250 mJ) and laser irradiation time (0–60 min) was studied. The rate of phenol removal process was characterized using UV absorption spectrometry, Raman spectroscopy and gas chromatography. In addition, the role of pH changes during the removal process was also investigated. Laser induced photo-catalytic process is highly efficient in removal of phenol in water over a short period of time (in minutes) as compared to conventional methods using lamps (hours). The phenol removal process pursued the first order kinetics with decay constant = 0.0125 min −1 .
Chunshan Song - One of the best experts on this subject based on the ideXlab platform.
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cr doped zns Semiconductor Catalyst with high catalytic activity for hydrogen production from hydrogen sulfide in non thermal plasma
Catalysis Today, 2019Co-Authors: Anjie Wang, Chunshan Song, Lu Zhao, Yao WangAbstract:Abstract A series of Al2O3 supported Cr-doped ZnS Semiconductor Catalysts with various Cr/Zn molar ratios were prepared by co-impregnation method, and investigated in non-thermal plasma induced H2S decomposition. The as-synthesized Catalysts were characterized using XRD, N2 adsorption/desorption, UV-visible spectroscopy, TEM, Raman, ICP and XPS techniques. Cr-doped ZnS with different amount of Cr possessed the significantly enhanced catalytic performance, compared to undoped ZnS. Variations in catalytic activity are discussed in terms of modification on the chemical and physical properties of the Cr–doped ZnS Catalysts. Among all the Catalysts, the Cr0.20-ZnS Catalyst showed the best catalytic behavior with full H2S conversion at lowest energy cost. Furthermore, the long-term study demonstrates that Cr–doped ZnS exhibits good stability in H2S decomposition.
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Hydrogen production via decomposition of hydrogen sulfide by synergy of non-thermal plasma and Semiconductor catalysis
International Journal of Hydrogen Energy, 2013Co-Authors: Lu Zhao, Anjie Wang, Chunshan Song, Xiang Li, Yao Wang, Yongkang HuAbstract:Abstract Direct H2S decomposition induced by plasma with an aid of alumina-supported metal sulfide Semiconductors (ZnS/Al2O3 and CdS/Al2O3) for the production of hydrogen was investigated in a dielectric barrier discharge (DBD) reactor. Effects of specific input energy (SIE), feed flow rate, metal sulfide loading, and added hydrogen on the performance of H2S decomposition were studied. With the aids of ZnS/Al2O3 and CdS/Al2O3, full conversion was obtained at reasonably low energy costs. The 100-h test runs indicated that both ZnS/Al2O3 and CdS/Al2O3 were stable in the course of H2S decomposition. A supported metal sulfide solid solution (Zn0.4Cd0.6S/Al2O3) exhibited higher performance than ZnS/Al2O3 and CdS/Al2O3, achieving full conversion at a reduced energy cost. The mechanism of the plasma-induced H2S decomposition with an aid of a Semiconductor Catalyst was tentatively proposed.
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New insight into the mechanism of enhanced photo-Fenton reaction efficiency for Fe-doped Semiconductors: A case study of Fe/g-C3N4
Catalysis Today, 1Co-Authors: Yan Liang, Chunshan Song, Hong Yang, Hainan Shi, Xinwen GuoAbstract:Abstract Visible light has shown to greatly enhance the activity of iron-doped Semiconductor Catalyst in a Fenton reaction system, however, the mechanism for this activity enhancement remains unclear. This work attempts to reveal the origin of this visible light driven activity enhancement by studying the iron doped Semiconductor Catalyst Fe/g-C3N4 in both photo-Fenton and dark Fenton reactions. Through analysis of XPS spectra of Catalyst, it is found that Fe2+/Fe3+ ratio for Fe/g-C3N4 Catalyst remains unchanged and sustained during the photo-Fenton reaction cycles. This is in direct contrast to the progressively decreased Fe2+/Fe3+ ratio observed in the dark Fenton reaction. It is clear that under visible light, Fe3+ is able to capture the photo-generated electrons from the Semiconductor and revert back to Fe2+, thus sustain the catalytic activity during the photo-Fenton reaction. This new mechanistic insight will guide the future design and optimization of high performance Catalysts by immobilizing transition metal ions in Semiconductors for advanced oxidation processes.
Zaki S. Seddigi - One of the best experts on this subject based on the ideXlab platform.
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Laser enhanced photo-catalytic removal of phenol from water using p-type NiO Semiconductor Catalyst.
Journal of hazardous materials, 2007Co-Authors: Mohammed A. Gondal, Mohammad N. Sayeed, Zaki S. SeddigiAbstract:Abstract Phenol is a carcinogen to humans and is a serious health concern, even at low concentrations. The efficient removal of phenol inside waste water is highly desirable. Laser induced photo-catalysis has been applied for removal of phenol from waste water using p-type NiO Semiconductor Catalyst for the first time. The characteristics of phenol removal using laser induced photo-catalytic process were investigated. The dependence of phenol removal on laser energy (100–250 mJ) and laser irradiation time (0–60 min) was studied. The rate of phenol removal process was characterized using UV absorption spectrometry, Raman spectroscopy and gas chromatography. In addition, the role of pH changes during the removal process was also investigated. Laser induced photo-catalytic process is highly efficient in removal of phenol in water over a short period of time (in minutes) as compared to conventional methods using lamps (hours). The phenol removal process pursued the first order kinetics with decay constant = 0.0125 min −1 .
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Laser-induced photo-catalytic removal of phenol using n-type WO3 Semiconductor Catalyst
Chemical Physics Letters, 2005Co-Authors: Mohammed A. Gondal, Zaki S. SeddigiAbstract:Abstract Laser-induced photo-catalytic degradation of phenol using WO3 was investigated for the first time. Effect of WO3 concentrations and laser energy on photo-catalytic removal of phenol from waste water was studied. Laser enhanced Photo-degradation can be an efficient method for the removal of phenol present in waste waters. The phenol removal process obeyed the first-order kinetics.
Z.h. Yamani - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen generation by laser transformation of methanol using n-type WO3 Semiconductor Catalyst
Journal of Molecular Catalysis A-chemical, 2004Co-Authors: Mohammed A. Gondal, Abdul Hameed, Z.h. YamaniAbstract:Abstract A laser based method for photocatalytic reforming of methanol at ambient temperature using n-type WO3 Semiconductor Catalyst has been investigated for the first time. A non-explosive mixture of gases containing hydrogen, carbon monoxide and methane with high concentration of hydrogen was observed. The amount of Catalyst and laser energy was optimized for maximum yield of hydrogen. The effect of aging of the Catalyst proved that there was no deactivation of Catalyst; instead, an increase in the activity of the Catalyst was observed. The effect of addition of water to methanol in various proportions as feedstock on the hydrogen yield during this laser induced photocatalytic process was also studied.
Lu Zhao - One of the best experts on this subject based on the ideXlab platform.
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cr doped zns Semiconductor Catalyst with high catalytic activity for hydrogen production from hydrogen sulfide in non thermal plasma
Catalysis Today, 2019Co-Authors: Anjie Wang, Chunshan Song, Lu Zhao, Yao WangAbstract:Abstract A series of Al2O3 supported Cr-doped ZnS Semiconductor Catalysts with various Cr/Zn molar ratios were prepared by co-impregnation method, and investigated in non-thermal plasma induced H2S decomposition. The as-synthesized Catalysts were characterized using XRD, N2 adsorption/desorption, UV-visible spectroscopy, TEM, Raman, ICP and XPS techniques. Cr-doped ZnS with different amount of Cr possessed the significantly enhanced catalytic performance, compared to undoped ZnS. Variations in catalytic activity are discussed in terms of modification on the chemical and physical properties of the Cr–doped ZnS Catalysts. Among all the Catalysts, the Cr0.20-ZnS Catalyst showed the best catalytic behavior with full H2S conversion at lowest energy cost. Furthermore, the long-term study demonstrates that Cr–doped ZnS exhibits good stability in H2S decomposition.
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Hydrogen production via decomposition of hydrogen sulfide by synergy of non-thermal plasma and Semiconductor catalysis
International Journal of Hydrogen Energy, 2013Co-Authors: Lu Zhao, Anjie Wang, Chunshan Song, Xiang Li, Yao Wang, Yongkang HuAbstract:Abstract Direct H2S decomposition induced by plasma with an aid of alumina-supported metal sulfide Semiconductors (ZnS/Al2O3 and CdS/Al2O3) for the production of hydrogen was investigated in a dielectric barrier discharge (DBD) reactor. Effects of specific input energy (SIE), feed flow rate, metal sulfide loading, and added hydrogen on the performance of H2S decomposition were studied. With the aids of ZnS/Al2O3 and CdS/Al2O3, full conversion was obtained at reasonably low energy costs. The 100-h test runs indicated that both ZnS/Al2O3 and CdS/Al2O3 were stable in the course of H2S decomposition. A supported metal sulfide solid solution (Zn0.4Cd0.6S/Al2O3) exhibited higher performance than ZnS/Al2O3 and CdS/Al2O3, achieving full conversion at a reduced energy cost. The mechanism of the plasma-induced H2S decomposition with an aid of a Semiconductor Catalyst was tentatively proposed.
