Combination effect of ZnO and activated carbon for solar assisted photocatalytic degradation of Direct Blue 53

Sobana, N.; Swaminathan, M.

doi:10.1016/j.solmat.2006.12.013

Cited by 152 publications

(57 citation statements)

References 30 publications

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“…[1][2][3] Metal oxides, such as ZnO, TiO 2 , TiO 2 :N and WO 3 have been widely utilized for photovoltiac (PV), photocatalytic and photoelectrochemical (PEC) cell devices. [4][5][6][7][8][9][10][11][12] Water splitting utilizing PEC cells has been an area of intense research, starting from the seminal work of Fujishima et al and followed by the work of Morisaki et al with TiO 2 . [3,13] The examination of III-V semiconductors is also of interest for hydrogen production.…”

Section: Introductionmentioning

confidence: 99%

Photoelectrochemical Study of Nanostructured ZnO Thin Films for Hydrogen Generation from Water Splitting

Wolcott

Smith

Kuykendall

et al. 2009

Adv Funct Materials

447

246

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Photoelectrochemical cells based on traditional and nanostructured ZnO thin films are investigated for hydrogen generation from water splitting. The ZnO thin films are fabricated using three different deposition geometries: normal pulsed laser deposition, pulsed laser oblique‐angle deposition, and electron‐beam glancing‐angle deposition. The nanostructured films are characterized by scanning electron microscopy, X‐ray diffraction, UV‐vis spectroscopy and photoelectrochemical techniques. Normal pulsed laser deposition produces dense thin films with ca. 200 nm grain sizes, while oblique‐angle deposition produces nanoplatelets with a fishscale morphology and individual features measuring ca. 900 by 450 nm on average. In contrast, glancing‐angle deposition generates a highly porous, interconnected network of spherical nanoparticles of 15–40 nm diameter. Mott‐Schottky plots show the flat band potential of pulsed laser deposition, oblique‐angle deposition, and glancing‐angle deposition samples to be −0.29, −0.28 and +0.20 V, respectively. Generation of photocurrent is observed at anodic potentials and no limiting photocurrents were observed with applied potentials up to 1.3 V for all photoelectrochemical cells. The effective photon‐to‐hydrogen efficiency is found to be 0.1%, 0.2% and 0.6% for pulsed laser deposition, oblique‐angle deposition and glancing‐angle deposition samples, respectively. The photoelectrochemical properties of the three types of films are understood to be a function of porosity, crystal defect concentration, charge transport properties and space charge layer characteristics.

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Section: Introductionmentioning

confidence: 99%

Photoelectrochemical Study of Nanostructured ZnO Thin Films for Hydrogen Generation from Water Splitting

Wolcott

Smith

Kuykendall

et al. 2009

Adv Funct Materials

447

246

View full text Add to dashboard Cite

show abstract

“…It is also abundant in nature and is environmental friendly (Wahab et al 2011). Moreover, ZnO is a better semiconductor as compared to commonly used TiO 2 , because widespread use of TiO 2 has been proved to be uneconomical for large scale water treatment operations (Sobana and Swaminathan 2007). Nevertheless, ZnO can also effectively degrade dyes in acidic or basic medium, and is cheaper than TiO 2 (Yang et al 2010;Xie and Wu 2010).…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and photocatalytic activity of PVP stabilized ZnO and modified ZnO nanostructures

et al. 2013

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In the present study, ZnO nanostructures have been successfully synthesized by hydrothermal, sonochemical and precipitation methods using polyvinyl pyrrolidone (PVP) as the capping agent. The ZnO nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-Visible spectroscopy and photoluminescence (PL) techniques. The XRD results revealed the hexagonal wurtzite structure of the ZnO nanostructures for all the samples. Furthermore, the morphology of the ZnO particles was obtained from FESEM micrographs. Particles prepared by hydrothermal method were found to be rice grain shaped and that prepared by precipitation and sonochemical methods were spherical shaped. Sunlight driven photocatalytic degradation of methylene blue (MB) was studied for ZnO nanostructures synthesized by various methods. The ZnO nanostructures were further decorated with Ag nanoparticles to enhance its dye degradation efficiency. The Ag decorated ZnO nanoparticles exhibited a higher degradation rate as compared to pure ZnO nanoparticles which was independent of pH. Since this process of dye degradation relies on the degradation of dye due to oxidation by highly reactive hydroxyl radicals, there are many factors which affect the efficiency of this process. Hence a study was conducted on the effect of various parameters on ZnO viz amount of catalyst, reaction pH and concentration of MB dye.

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“…Pollutant concentration was adsorbed by the walnut and almond shells and it was degraded by ZnO nano-particles, which are on the absorbents' surface [31]. The results are shown in Figure 4.…”

Section: Simultaneous Use Of Adsorption-photocatalytic Processesmentioning

confidence: 99%

An investigation on Removal Efficiency of Direct Blue 71 by ZnO Nano-Particles and Activated Carbon Produced from Agricultural Wastes

Larimi

Ayati

2017

IJEE

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Keywords:pH dye removal COD photocatalytic process adsorption A B S T R A C TThe present study used the adsorption process of activated carbon produced from agricultural wastes and the photocatalytic process of nano-ZnO to break down complex compounds available in removing Direct Blue 71 (henceforth, DB71). The two processes were done under three varied circumstancesadsorption/photocatalytic, photocatalytic/ adsorption, and simultaneous use of the processes. First, DB71 was exposed to activated carbon produced from walnut and almond shells and the efficiency achieved at equilibrium time (45 and 60 minutes) was 55 and 60 percent, respectively. Then, DB71 was exposed to different dosages of nano-ZnO to remove the dye completely. The result showed that amount of AC/ZnO in an optimum condition for two walnut and almond shell absorbents were 0.75/0.096 and1/0.096 g/L. Second, (photocatalytic/ adsorption) the complex compound of DB71 with a dosage of 0.024 g/L was broken down as a result of UV radiation. The experiment proceeded with different dosages of walnut and almond shells after achieving the efficiency of 50% in removing DB71 in the second process. The amounts of AC/ZnO were 0.75/0.024 and 1/0.024 for walnut and almond shells respectively under the optimum condition for the second process. In the third process advantages of the simultaneous use of photocatalytic and adsorption processes were taken in which different dosages of AC/ ZnO were used. Given the smaller dosages of nano-ZnO and less dye removal time, amounts of 0.75/ 0.288 g/L and 0.75/0.288 g/L were measured for walnut and almond shells. The findings show that photocatalytic/adsorption process was the more optimal process because of the less dosages of nano-ZnO, efficiency of removing DB71 and shorter dye removing time. Furthermore, the effect of the intensity of UV radiant on the efficiency and time of removing DB71 was also examined. The experiment revealed that removing COD in the optimum conditions were 47.22 and 49.6 and 62.23 and 63.15 percent using walnut and almond shell respectively both in the first experiment and the simulations use of adsorption and photocatalytic processes after 30 hours. While, in the second experiment (photocatalytic/ adsorption) 42.21 and 39.18 percent of COD were removed using walnut and almond shell respectively after 30 hours. The LC-mass test of photocatalytic/adsorption process also showed the degradation of DB 71 complex compounds.

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Combination effect of ZnO and activated carbon for solar assisted photocatalytic degradation of Direct Blue 53

Cited by 152 publications

References 30 publications

Photoelectrochemical Study of Nanostructured ZnO Thin Films for Hydrogen Generation from Water Splitting

Photoelectrochemical Study of Nanostructured ZnO Thin Films for Hydrogen Generation from Water Splitting

Synthesis, characterization and photocatalytic activity of PVP stabilized ZnO and modified ZnO nanostructures

An investigation on Removal Efficiency of Direct Blue 71 by ZnO Nano-Particles and Activated Carbon Produced from Agricultural Wastes

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