Improved Training in Mathematics for Engineering Students: E-Courses

Rozhkova, S. V.; Rozhkova, V. I.; Lasukov, Vladimir; Chervach, Maria

doi:10.21125/inted.2017.1511

Cited by 2 publications

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“…Artificial photosynthesis is the concept of replicating the natural process of photosynthesis by capturing solar energy in chemical bonds. − Although the concept dates back to the early 20th century, there has been increasing recent interest in developing artificial photosynthesis schemes which could create a sustainable energy supply and combat the effects of climate change due to fossil fuel combustion. − In this context, photoelectrochemical (PEC) water splitting is an artificial photosynthesis approach which performs solar to fuel conversion through the generation of hydrogen and oxygen. − …”

Section: Introductionmentioning

confidence: 99%

Undoped and Ni-Doped CoO_x Surface Modification of Porous BiVO₄ Photoelectrodes for Water Oxidation

et al. 2016

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ABSTRACT:Surface modification of photoanodes with oxygen evolution reaction (OER) catalysts is an effective approach to enhance water oxidation kinetics, to reduce external bias, and to improve the energy harvesting efficiency of photoelectrochemical (PEC) water oxidation. Here, the surface of porous BiVO4 photoanodes was modified by the deposition of undoped and Ni-doped CoOx via nitrogen flow assisted electrostatic spray pyrolysis. This newly developed atmospheric pressure deposition technique allows for surface coverage throughout the porous structure with thickness and composition control. PEC testing of modified BiVO4 photoanodes show that after deposition of an undoped CoOx surface layer, the onset potential shifts negatively by ca. 420 mV and the photocurrent density reaches 2.01 mA·cm -2 at 1.23 vs. VRHE under AM 1.5G illumination.Modification with Ni-doped CoOx produces even more effective OER catalysis and yields a photocurrent density of 2.62 mA·cm -2 at 1.23 VRHE under AM 1.5G illumination. The valence band X-ray photoelectron spectroscopy and synchrotron-based X-ray absorption spectroscopy results show the Ni doping reduces the Fermi level of the CoOx layer; the increased surface band bending produced by this effect is partially responsible for the superior PEC performance.3

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Section: Introductionmentioning

confidence: 99%

Undoped and Ni-Doped CoO_x Surface Modification of Porous BiVO₄ Photoelectrodes for Water Oxidation

et al. 2016

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“…The construction of artificial mimics of PS II presents a major challenge and has been the subject of a large body of work. − One crucial problem in designing any such system is to find a suitable mimic for P 680 . This species must act as a photosensitizer and have an oxidation midpoint potential that is high enough to remove electrons from water.…”

Section: Introductionmentioning

confidence: 99%

Phosphorus(V) Porphyrin-Manganese(II) Terpyridine Conjugates: Synthesis, Spectroscopy, and Photo-Oxidation Studies on a SnO₂Surface

et al. 2016

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A major challenge in designing artificial photosynthetic systems is to find a suitable mimic of the highly oxidizing photoactive species P in photosystem II. High-potential phosphorus(V) porphyrins have many attractive properties for such a mimic but have not been widely studied. Here, we report the synthesis and photophysical characterization of a novel phosphorus(V) octaethylporphyrin-oxyphenyl-terpyridine conjugate (PPor-OPh-tpy, 1) and its corresponding manganese(II) complex (PPor-OPh-Mn(tpy)Cl, 2). The X-ray structure of 2 shows that the Mn(II) and P(V) centers are 11.783 Å apart and that the phenoxy linker is not fully conjugated with the terpyridine ligand. The porphyrin fluorescence in 1 and 2 is strongly quenched and has a shorter lifetime compared to a reference compound without the terpyridine ligand. This suggests that electron transfer from tpy or Mn(tpy) to the excited singlet state of the PPor may be occurring. However, femtosecond transient absorbance data show that the rate of relaxation to the ground state in 1 and 2 is comparable to the fluorescence lifetimes. Thus, if charge separation is occurring, its lifetime is short. Because both 1 and 2 are positively charged, they can be electrostatically deposited onto the surface of negatively charged SnO nanoparticles. Freeze-trapping EPR studies of 2 electrostatically bound to SnO suggest that excitation of the porphyrin results in electron injection from PPor* into the conduction band of SnO and that the resulting PPor species acquires enough potential to photo-oxidize the axially bound Mn(II) (tpy) moiety to Mn(III) (tpy).

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Improved Training in Mathematics for Engineering Students: E-Courses

Cited by 2 publications

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Undoped and Ni-Doped CoO_x Surface Modification of Porous BiVO₄ Photoelectrodes for Water Oxidation

Undoped and Ni-Doped CoO_x Surface Modification of Porous BiVO₄ Photoelectrodes for Water Oxidation

Phosphorus(V) Porphyrin-Manganese(II) Terpyridine Conjugates: Synthesis, Spectroscopy, and Photo-Oxidation Studies on a SnO₂Surface

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Improved Training in Mathematics for Engineering Students: E-Courses

Cited by 2 publications

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Undoped and Ni-Doped CoOx Surface Modification of Porous BiVO4 Photoelectrodes for Water Oxidation

Undoped and Ni-Doped CoOx Surface Modification of Porous BiVO4 Photoelectrodes for Water Oxidation

Phosphorus(V) Porphyrin-Manganese(II) Terpyridine Conjugates: Synthesis, Spectroscopy, and Photo-Oxidation Studies on a SnO2Surface

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Undoped and Ni-Doped CoO_x Surface Modification of Porous BiVO₄ Photoelectrodes for Water Oxidation

Undoped and Ni-Doped CoO_x Surface Modification of Porous BiVO₄ Photoelectrodes for Water Oxidation

Phosphorus(V) Porphyrin-Manganese(II) Terpyridine Conjugates: Synthesis, Spectroscopy, and Photo-Oxidation Studies on a SnO₂Surface