Effect of pH on solar photocatalytic reduction and deposition of Cu(II), Ni(II), Pb(II) and Zn(II): Speciation modeling and reaction kinetics

Kabra, Kavita; Chaudhary, Rubina; Sawhney, Ravinder Singh

doi:10.1016/j.jhazmat.2007.04.028

Cited by 43 publications

(18 citation statements)

References 6 publications

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“…While electrostatics between ammonium ion and the surface did not appear to play a major role in the observed pH dependence, it did play a role in the photooxidation of nitrite to nitrate. Dependences on pH have also been observed in various photoreduction reactions [1001,1142,[1298][1299][1300]. In many cases, the influence of pH on photochemical reactions relates to adsorbate stabilities and not necessarily to electron transfer events [993,1290,1298,1299,[1301][1302][1303][1304][1305].…”

Section: Acidic and Basic Conditionsmentioning

confidence: 97%

“…Examples of metal cation systems examined in the literature include: Ag + [524,525,[1105][1106][1107][1108][1109][1110][1111][1112][1113][1114][1115][1116][1117][1118]; Au 3+ [1117,[1119][1120][1121]; Cd 2+ [1122][1123][1124]; Cr 6+ [233,1119,[1125][1126][1127][1128][1129][1130][1131][1132][1133][1134][1135][1136][1137][1138][1139][1140]; Cu 2+ [1119,1125,1128,1130,1135,[1141][1142][1143]…”

Section: Photoreduction Reactantsmentioning

confidence: 99%

“…Numerous groups have also shown that these potentials can be shifted (to increase or decrease activity) by pH, by electrolyte concentration or by coadsorbates. Kabra and coworkers [1125,1141,1142] The boundary region between active and inactive metal cations in the assessment of Rajeshwar et al [1119] is the TiO 2 CB minimum position. However, potential energy can be lost due to electron trapping (see Section 2.4), which places an additional limitation on the reductive power of TiO 2 .…”

Section: Photoreduction Reactantsmentioning

confidence: 99%

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A surface science perspective on TiO2 photocatalysis

Henderson

2011

Surface Science Reports

1,857

1,634

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a b s t r a c tThe field of surface science provides a unique approach to understanding bulk, surface and interfacial phenomena occurring during TiO 2 photocatalysis. This review highlights, from a surface science perspective, recent literature that provides molecular-level insights into photon-initiated events occurring at TiO 2 surfaces. Seven key scientific issues are identified in the organization of this review. These are: (1) photon absorption, (2) charge transport and trapping, (3) electron transfer dynamics, (4) the adsorbed state, (5) mechanisms, (6) poisons and promoters, and (7) phase and form. This review ends with a brief examination of several chemical processes (such as water splitting) in which TiO 2 photocatalysis has made significant contributions in the literature.

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Section: Acidic and Basic Conditionsmentioning

confidence: 97%

Section: Photoreduction Reactantsmentioning

confidence: 99%

Section: Photoreduction Reactantsmentioning

confidence: 99%

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A surface science perspective on TiO2 photocatalysis

Henderson

2011

Surface Science Reports

1,857

1,634

View full text Add to dashboard Cite

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“…However, it is difficult to remove the total ions by sole adsorption due to an accompanying desorption process. In order to compensate for the drawback, subsequent photoelectrodeposition of adsorbed Pb (II) ions has been attempted by TiO 2 -photocatalytic oxidation [3,4] or reduction [5][6][7][8][9]. According to thermodynamic constraints, photocatalytic reduction of Pb (II) ions is a minor route and requires a hole scavenger for the reaction to proceed, whereas Pb (II) ions are mainly oxidized to PbO 2 by TiO 2 -photocatalysis under O 2 or O 3 [3,4].…”

Section: Introductionmentioning

confidence: 99%

Improving Effect of MnO<sub>2</sub> Addition on TiO<sub>2</sub>-Photocatalytic Removal of Lead Ion from Water

Kobayashi

Kanasaki

Nozaki

et al. 2017

J. of Wat. & Envir. Tech.

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Removal of Pb (II) ions from water was carried out by a coupling approach of adsorption and photoelectrodeposition over a porous TiO 2 photocatalyst loaded with MnO 2 . The addition of MnO 2 onto the porous TiO 2 accelerated the photocatalytic oxidation of Pb (II) ions, which was caused by a strong interaction between MnO 2 and Pb (II) ions. Since the same effect was not observed on the photocatalytic degradation of methylene blue over MnO 2 /TiO 2 photocatalysts, the photoelectrodeposition reaction rate appears to be determined by the amount of Pb (II) ions adsorbed on the surface of porous TiO 2 loaded with MnO 2 .

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“…Its binding forms are effected by soil properties including pH, cation exchange capacity, oxidation-reduction status, contents of organic matter, calcium carbonate and Fe and Mn oxides (Kabra et al, 2007;Usman, 2008). The soil moisture condition controls both the soil redox potentials (Eh) and the biological activity, and led to change in the transformation and repartitioning of the heavy metals in soil (Shuman, 1980;Han et al, 2001;Tack et al, 2006;Makino et al, 2000;Zheng and Zhang, 2011;Xu et al, 2014) and plant uptakes (Xu et al, 2013a).…”

Section: Introductionmentioning

confidence: 99%

Water Saving Irrigation Improves the Solubility and Bioavailability of Zinc in Rice Paddy

YuPing²,

Sung-Bum³

et al. 2015

IJAB

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Fields experiment was done to investigate the effect of a typical water saving irrigation technique, namely non-flooding controlled irrigation (NFI), on the extractability, solubility, and bioavailability of zinc (Zn) in a non-polluted paddy soil. The Zn contents in the soil solutions, soil extractions by modified BCR (European Community Bureau of Reference) sequential extraction procedure, and the plant digestions were measured. Compared with the Zn in flooding irrigation (FI) soil, Zn contents in extractable (EXT) form and Zn contents in soil solutions was increased in 0-20 cm NFI soil, accompanied with a little reduction of soil Zn in oxidizable (OXD) form. That confirmed the Zn in OXD form was released into soil solution under the wetting-drying cycle condition in NFI fields, and hence resulted in high extractability and solubility of Zn in top surface soil. As a result, Zn contents in the rice plant parts in NFI fields were higher than in FI fields. It can be concluded that NFI irrigation is help to enhance soil Zn bioavailability and food Zn nutrients status in the soil without Zn-pollution and Zn deficiency, but might led to soil Zn depletion in Zn deficient soil or rice foodstuffs pollution in Zn-polluted soil.

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Effect of pH on solar photocatalytic reduction and deposition of Cu(II), Ni(II), Pb(II) and Zn(II): Speciation modeling and reaction kinetics

Cited by 43 publications

References 6 publications

A surface science perspective on TiO2 photocatalysis

A surface science perspective on TiO2 photocatalysis

Improving Effect of MnO<sub>2</sub> Addition on TiO<sub>2</sub>-Photocatalytic Removal of Lead Ion from Water

Water Saving Irrigation Improves the Solubility and Bioavailability of Zinc in Rice Paddy

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