Undesired Role of Sacrificial Reagents in Photocatalysis

Schneider, Jenny; Bahnemann, Detlef W.

doi:10.1021/jz4018199

Cited by 472 publications

(379 citation statements)

References 34 publications

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“…The photoinduced holes from VB of TiO2 NRs are irreversibly scavenged by methanol to produce various oxidation intermediates and products such as  OH radical,  CH2OH, HCHO, HCOOH and CO2. 31,35,50 Meanwhile, the photogenerated electrons simultaneously reduce the protons and water to generate H2 gas.…”

Section: Sem Images Inmentioning

confidence: 99%

Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods

et al. 2015

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The immobilization of miniscule quantities of RuO2 (~ 0.1%) onto one-dimensional (1D) TiO2 nanorods (NRs) allows H2 evolution from water under the irradiation of visible light.Rod-like rutile TiO2 structures, exposing preferentially (110) surfaces, are shown to be critical for the deposition of RuO2 to enable photocatalytic activity in the visible region. This performance is rationalized based on fundamental experimental studies and theoretical calculations, demonstrating that RuO2(110) grown as 1D nanowires on rutile TiO2(110), which occurs only at extremely low loads of RuO2, leads to the formation of a heterointerface that efficiently adsorbs visible light.

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Section: Sem Images Inmentioning

confidence: 99%

Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods

et al. 2015

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“…3(b), showing irreversible oxidation of CH 3 OH by photogenerated holes from the valence band of InGaN. 38 In an oxygen (O 2 ) free environment, the intermediate compound eventually injects e − into the conduction band of the semiconductor, leading to the formation of formaldehyde (HCHO) as a stable product which could further be oxidized to methanoic acid (HCOOH) and subsequently to CO 2 along with H 2 generation. 16,38,39 Rh nanoparticles on the nanowire surfaces behave as an electron sink and reduce protons to H 2 .…”

mentioning

confidence: 99%

“…38 In an oxygen (O 2 ) free environment, the intermediate compound eventually injects e − into the conduction band of the semiconductor, leading to the formation of formaldehyde (HCHO) as a stable product which could further be oxidized to methanoic acid (HCOOH) and subsequently to CO 2 along with H 2 generation. 16,38,39 Rh nanoparticles on the nanowire surfaces behave as an electron sink and reduce protons to H 2 . Figure 3(c) depicts the average H 2 evolution rate derived from ∼6 h of photocatalytic reaction for In 0.23 Ga 0.77 N nanowires with an optimum Mg doping level (T Mg = 200 • C) under illumination by a 300 W xenon lamp with AM1.5G filter and with various long-pass filters.…”

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confidence: 99%

Group III-nitride nanowire structures for photocatalytic hydrogen evolution under visible light irradiation

Chowdhury

Kibria

et al. 2015

APL Materials

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The performance of photochemical water splitting over the emerging nanostructured photocatalysts is often constrained by their surface electronic properties, which can lead to imbalance in redox reactions, reduced efficiency, and poor stability. We have investigated the impact of surface charge properties on the photocatalytic activity of InGaN nanowires. By optimizing the surface charge properties through controlled p-type dopant (Mg) incorporation, we have demonstrated an apparent quantum efficiency of ∼17.1% and ∼12.3% for InGaN nanowire arrays under visible light irradiation (400 nm–490 nm) in aqueous methanol and in the overall neutral-pH water splitting reaction, respectively.

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“…to sulfate radicals), and the QE values may not reflect the true photonic efficiency, as quoted in the literature. 53 The choice of the reagent was, however, carefully conducted to be able to carry out the reactions under alkaline conditions (pH [12][13][14] and an internal comparison of QE should be still valid. Separate experiments confirmed that no O2 was evolved under dark in the presence of photocatalyst or under illumination in the absence of photocatalyst.…”

Section: Figure 1 (A) Time Courses Of Photocatalytic Oermentioning

confidence: 99%

Enhanced Kinetics of Hole Transfer and Electrocatalysis during Photocatalytic Oxygen Evolution by Cocatalyst Tuning

et al. 2016

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Understanding photophysical and electrocatalytic processes during photocatalysis in a powder suspension system is crucial for developing efficient solar energy conversion systems. We report a substantial enhancement by a factor of 3 in photocatalytic efficiency for the oxygen evolution reaction (OER) by adding trace amounts (~0.05 wt%) of noble metals (Rh or Ru) to a 2 wt% cobalt oxide-modified Ta3N5 photocatalyst particulate. The optimized system exhibited high quantum efficiencies (QEs) of up to 28 and 8.4% at 500 and 600 nm in 0.1 M Na2S2O8 at pH 14. By isolating the electrochemical components to generate doped cobalt oxide electrodes, the electrocatalytic activity of cobalt oxide when doped with Ru or Rh was improved compared with cobalt oxide, as evidenced by the onset shift for electrochemical OER. Density functional theory (DFT) calculation shows that the effects of a second metal addition perturbs the electronic structure and redox properties in such a way that both hole transfer kinetics and electrocatalytic rates improve. Time resolved terahertz spectroscopy (TRTS) measurement provides evidence of long-lived electron populations (>1 ns; with mobilities μe ~0.1-3 cm 2 V -1 s -1 ), which are not perturbed by the addition of CoOx-related phases. Furthermore, we find that Ta3N5 phases alone suffer ultrafast hole trapping (within 10 ps); the CoOx and M-CoOx decorations most likely induce a kinetic competition between hole transfer toward the CoOx-related phases and trapping in the Ta3N5 phase, which is consistent with the improved OER rates. The present work not only provides a novel way to improve electrocatalytic and photocatalytic performance but also gives additional tools and insight to understand the characteristics of photocatalysts that can be used in a suspension system.

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Undesired Role of Sacrificial Reagents in Photocatalysis

Cited by 472 publications

References 34 publications

Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods

Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods

Group III-nitride nanowire structures for photocatalytic hydrogen evolution under visible light irradiation

Enhanced Kinetics of Hole Transfer and Electrocatalysis during Photocatalytic Oxygen Evolution by Cocatalyst Tuning

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Undesired Role of Sacrificial Reagents in Photocatalysis

Cited by 472 publications

References 34 publications

Visible Light-Driven H2 Production over Highly Dispersed Ruthenia on Rutile TiO2 Nanorods

Visible Light-Driven H2 Production over Highly Dispersed Ruthenia on Rutile TiO2 Nanorods

Group III-nitride nanowire structures for photocatalytic hydrogen evolution under visible light irradiation

Enhanced Kinetics of Hole Transfer and Electrocatalysis during Photocatalytic Oxygen Evolution by Cocatalyst Tuning

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Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods

Visible Light-Driven H₂ Production over Highly Dispersed Ruthenia on Rutile TiO₂ Nanorods