Prediction of Flatband Potentials at Semiconductor‐Electrolyte Interfaces from Atomic Electronegativities

Butler, M. A.; Ginley, David S.

doi:10.1149/1.2131419

Cited by 1,171 publications

(611 citation statements)

References 15 publications

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“…36 The relevant E c and E v levels, which were calculated by the Nernst relation, under neutral conditions are shown in Table S3. 37 In general, ROS can be generated using the incident photon energy and interfacial electron (e cb •− generation. 39 As an N-type semiconductor, 40 nFe 2 O 3 may have an upward-bending conduction band owing to the accumulation of positive charge within the space charge region of the electrostatic double layer.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Quantitative Analysis of Reactive Oxygen Species Photogenerated on Metal Oxide Nanoparticles and Their Bacteria Toxicity: The Role of Superoxide Radicals

Wang

Zhao

et al. 2017

Environ. Sci. Technol.

169

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Ecotoxicity of engineered nanoparticles (NPs) has become the focus of considerable attention because of their wide applications. Reactive oxygen species (ROS) play important roles in the toxicity mechanisms of engineered metal oxide NPs. This work aimed to understand quantitatively the contribution of photogenerated ROS on metal oxide NPs to their toxicity. The dynamic generation of O 2•− , • OH, and H 2 O 2 in aqueous suspensions of photoilluminated metal oxide nano-and bulk particles (TiO 2 , ZnO, V 2 O 5 , CeO 2 , Fe 2 O 3 , and Al 2 O 3 ) was measured by a continuous-flow chemiluminescence (CFCL) detection system. Superoxides were generated on all six nanoparticles as well as bulk TiO 2 and ZnO, with nano TiO 2 producing the highest concentration (180 nM). Hydroxyl radicals were detected on both nano-and bulk TiO 2 and ZnO, whereas H 2 O 2 was detected only on TiO 2 and ZnO nanoparticles. The generation of ROS can in general be interpreted by the electronic structures and surface defects of the NPs and the ROS redox potentials. Furthermore, acute toxicity of the six metal oxide particles to a luminescent bacterium, P. phosphoreum 502 was assessed after photoillumination. The toxicity effect was attributed to the long-lived O 2 •− radicals on the nanoparticlce, and its potency follows the order of TiO 2 > ZnO > V 2 O 5 > Fe 2 O 3 > CeO 2 > Al 2 O 3 , which is the same as the order of the O 2•− concentration measured by CFCL. Our work revealed quantitatively the important role superoxide radicals play in the toxicity of various metal oxide nanoparticles after photoillumination.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Quantitative Analysis of Reactive Oxygen Species Photogenerated on Metal Oxide Nanoparticles and Their Bacteria Toxicity: The Role of Superoxide Radicals

Wang

Zhao

et al. 2017

Environ. Sci. Technol.

169

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“…Similarly, adsorption of other ions from solution or the intentional modification of the surface with adsorbants with a large dipole moment [114] will shift the photocatalyst potentials relative to those of the solution red-ox reactions and can be used to engineer the potentials of a photocatalyst beyond what is possible by changing the bulk chemical composition alone. Please see work by Butler et al [115] and Stevanovic et al [89] on how this influences the comparison between computational prediction and experimental measurement.…”

Section: Thermodynamic Driving Forcementioning

confidence: 99%

Modelling materials for solar fuel synthesis by artificial photosynthesis; predicting the optical, electronic and redox properties of photocatalysts

Guiglion

Berardo

Butchosa

et al. 2016

J. Phys.: Condens. Matter

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In this mini-review, we discuss what insight computational modelling can provide into the working of photocatalysts for solar fuel synthesis and how calculations can be used to screen for new promising materials for photocatalytic water splitting and carbon dioxide reduction. We will extensively discuss the different relevant (material) properties and the computational approaches (DFT, TD-DFT, GW/BSE) available to model them. We illustrate this with examples from the literature, focussing on polymeric and nanoparticle photocatalysts. We finish with a perspective on the outstanding conceptual and computational challenges.

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“…As reviewed by Xu and Schoonen (24), the Fermi level and absolute energy positions of conduction and valence bands of pristine semiconductor minerals can be closely estimated using the method proposed by Bulter and Ginley (25). According to this method, the Fermi level energy of ferrihydrite can be calculated from the geometric mean of the electronegativities of its constituent atoms.…”

Section: Evaluation Of a Mechanism Involving Electron Transfer Reactimentioning

confidence: 99%

Kinetics of Fe(II)-Catalyzed Transformation of 6-line Ferrihydrite under Anaerobic Flow Conditions

Yang

Steefel

Marcus

et al. 2010

Environ. Sci. Technol.

137

138

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The readsorption of ferrous ions produced by the abiotic and microbially-mediated reductive dissolution of iron oxy-hydroxides drives a series of transformations of the host minerals. To further understand the mechanisms by which these transformations occur and their kinetics within a microporous flow environment, flow-through experiments were conducted in which capillary tubes packed with ferrihydrite-coated glass spheres were injected with inorganic Fe(II) solutions under circumneutral pH conditions at 25ºC. Synchrotron X-ray diffraction was used to identify the secondary phase(s) formed and to provide data for quantitative kinetic analysis. At concentrations at and above 1.8 mM Fe(II) in the injection solution, magnetite was the only secondary phase formed (no intermediates were detected), with complete transformation following a nonlinear rate law requiring 28 hours and 150 hours of reaction at 18 and 1.8 mM Fe(II), respectively. However, when the injection solution consisted of 0.36 mM Fe(II), goethite was the predominant reaction product and formed much more slowly according to a linear rate law, while only minor magnetite was formed. When the rates are normalized based on the time to react half of the ferrihydrite on a reduced time plot, it is apparent that the 1.8 mM and 18 mM input Fe(II) experiments can be described by the same reaction mechanism, while the 0.36 input Fe(II) experiment is distinct. The analysis of the transformation kinetics suggest that the transformations involved an electron transfer reaction between the aqueous as well as sorbed Fe(II) and ferrihydrite acting as a semiconductor, rather than a simple dissolution and recrystallization mechanism. A transformation mechanism involving sorbed inner sphere Fe(II) alone is not supported, since the essentially equal coverage of sorption sites in the 18 mM and 1.8 mM Fe(II) injections cannot explain the difference in the transformation rates observed.

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Prediction of Flatband Potentials at Semiconductor‐Electrolyte Interfaces from Atomic Electronegativities

Cited by 1,171 publications

References 15 publications

Quantitative Analysis of Reactive Oxygen Species Photogenerated on Metal Oxide Nanoparticles and Their Bacteria Toxicity: The Role of Superoxide Radicals

Quantitative Analysis of Reactive Oxygen Species Photogenerated on Metal Oxide Nanoparticles and Their Bacteria Toxicity: The Role of Superoxide Radicals

Modelling materials for solar fuel synthesis by artificial photosynthesis; predicting the optical, electronic and redox properties of photocatalysts

Kinetics of Fe(II)-Catalyzed Transformation of 6-line Ferrihydrite under Anaerobic Flow Conditions

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