Theoretical insight into the roles of cocatalysts in the Ni–NiO/β-Ga2O3 photocatalyst for overall water splitting

Linear conjugated polymers have potential as photocatalysts for hydrogen production from water but so far, most studies have involved non-scalable sacrificial reagents. Z-schemes comprising more than one semiconductor are a potential solution, but it is challenging to design these systems because multiple components must work together synergistically. Here, we show that a conjugated polymer photocatalyst for proton reduction can be coupled in a Z-scheme with an inorganic water oxidation photocatalyst to promote overall water splitting without any sacrificial reagents. First, a promising combination of an organic catalyst, an inorganic catalyst, and a redox mediator was identified by using high-throughput screening of a library of components. A Z-scheme system composed of P10 (homopolymer of dibenzo[b,d]thiophene sulfone)-Fe2+/Fe3+-BiVO4 was then constructed for overall water splitting under visible light irradiation. Transient absorption spectroscopy was used to assign timescales to the various steps in the photocatalytic process. While the overall solar-to-hydrogen efficiency of this first example is low, it provides proof of concept for other hybrid organic-inorganic Z-scheme architectures in the future.

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Photocatalyst Z-Scheme System Composed of a Linear Conjugated Polymer and BiVO4 for Overall Water Splitting Under Visible Light

10.26434/chemrxiv.12252317.v1 ◽

2020 ◽

Author(s):

Yang Bai ◽

Keita Nakagawa ◽

Alexander Cowan ◽

Catherine Aitchison ◽

Yuichi Yamaguchi ◽

...

Keyword(s):

Visible Light ◽

Water Splitting ◽

Water Oxidation ◽

Conjugated Polymer ◽

High Throughput Screening ◽

Transient Absorption ◽

Transient Absorption Spectroscopy ◽

Proton Reduction ◽

Overall Water Splitting ◽

Multiple Components

Linear conjugated polymers have potential as photocatalysts for hydrogen production from water but so far, most studies have involved non-scalable sacrificial reagents. Z-schemes comprising more than one semiconductor are a potential solution, but it is challenging to design these systems because multiple components must work together synergistically. Here, we show that a conjugated polymer photocatalyst for proton reduction can be coupled in a Z-scheme with an inorganic water oxidation photocatalyst to promote overall water splitting without any sacrificial reagents. First, a promising combination of an organic catalyst, an inorganic catalyst, and a redox mediator was identified by using high-throughput screening of a library of components. A Z-scheme system composed of P10 (homopolymer of dibenzo[b,d]thiophene sulfone)-Fe2+/Fe3+-BiVO4 was then constructed for overall water splitting under visible light irradiation. Transient absorption spectroscopy was used to assign timescales to the various steps in the photocatalytic process. While the overall solar-to-hydrogen efficiency of this first example is low, it provides proof of concept for other hybrid organic-inorganic Z-scheme architectures in the future.

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Rational introduction of S and P in multi-stage electrocatalyst to drive a large-current-density water oxidation reaction and overall water splitting

Journal of Power Sources ◽

10.1016/j.jpowsour.2021.230757 ◽

2022 ◽

Vol 518 ◽

pp. 230757

Author(s):

Yijie Zhang ◽

Leran Liu ◽

Jinwei Wang ◽

Rui Yao ◽

Yun Wu ◽

...

Keyword(s):

Water Splitting ◽

Current Density ◽

Water Oxidation ◽

Oxidation Reaction ◽

Overall Water Splitting ◽

Large Current ◽

Multi Stage ◽

Large Current Density

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Single-atom cobalt-hydroxyl modification of polymeric carbon nitride for highly enhanced photocatalytic water oxidation: ball milling increased single atom loading

Chemical Science ◽

10.1039/d1sc06555f ◽

2022 ◽

Author(s):

Fei Yu ◽

Tingting Huo ◽

Quanhua Deng ◽

Guoan Wang ◽

Yuguo Xia ◽

...

Keyword(s):

Ball Milling ◽

Water Splitting ◽

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Water Oxidation ◽

Carbon Nitride ◽

Single Atom ◽

Overall Water Splitting ◽

Polymeric Carbon

Expediting the oxygen evolution reaction (OER) is the key to achieving efficient photocatalytic overall water splitting. Herein, single-atom Co−OH modified polymeric carbon nitride (Co-PCN) was synthesized with single-atom loading increased...

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Molecular Catalysts Immobilized on Semiconductor Photosensitizers for Proton Reduction toward Visible‐Light‐Driven Overall Water Splitting

ChemSusChem ◽

10.1002/cssc.201900441 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1807-1824 ◽

Cited By ~ 10

Author(s):

Takeshi Morikawa ◽

Shunsuke Sato ◽

Keita Sekizawa ◽

Takeo Arai ◽

Tomiko M. Suzuki

Keyword(s):

Visible Light ◽

Water Splitting ◽

Proton Reduction ◽

Overall Water Splitting ◽

Visible Light Driven ◽

Molecular Catalysts

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Integration of Bio-inspired lanthanide-transition metal cluster and P-doped carbon nitride for efficient photocatalytic overall water splitting

National Science Review ◽

10.1093/nsr/nwaa234 ◽

2020 ◽

Author(s):

Rong Chen ◽

Gui-Lin Zhuang ◽

Zhi-Ye Wang ◽

Yi-Jing Gao ◽

Zhe Li ◽

...

Keyword(s):

Transition Metal ◽

Water Splitting ◽

Water Oxidation ◽

Transient Absorption ◽

Metal Cluster ◽

Photoexcited Electron ◽

Ps Ii ◽

Heterometallic Cluster ◽

Overall Water Splitting ◽

Oxygen Evolving

Abstract Photosynthesis in nature uses the Mn4CaO5 cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II (PS II). Herein, we demonstrate a bio-inspired heterometallic cluster LnCo3 (Ln = Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of CaMn4O5 cluster. Anchoring LnCo3 on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents. The NdCo3/PCN-c photocatalyst exhibits excellent water splitting activity and a quantum efficiency of 2.0% at 350 nm. Ultrafast transient absorption (TA) spectroscopy revealed the transfer of photoexcited electron and hole into the PCN and LnCo3 for hydrogen and oxygen evolution reactions, respectively. DFT calculation showed the cooperative water activation on lanthanide and O-O bond formation on transition metal for water oxidation. This work not only prepares a synthetic model of bio-inspired oxygen-evolving center but also provides an effective strategy to realize light-driven overall water splitting.

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Mediator-assisted water oxidation by the ruthenium “blue dimer” cis,cis-[(bpy)2(H2O)RuORu(OH2)(bpy)2]4+

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0807153105 ◽

2008 ◽

Vol 105 (46) ◽

pp. 17632-17635 ◽

Cited By ~ 92

Author(s):

Javier J. Concepcion ◽

Jonah W. Jurss ◽

Joseph L. Templeton ◽

Thomas J. Meyer

Keyword(s):

Carbon Dioxide ◽

Electron Transfer ◽

Renewable Energy ◽

Photosystem Ii ◽

Water Splitting ◽

Water Oxidation ◽

Oxygenic Photosynthesis ◽

Reduced Water ◽

Insight Into ◽

Recent Insight

Light-driven water oxidation occurs in oxygenic photosynthesis in photosystem II and provides redox equivalents directed to photosystem I, in which carbon dioxide is reduced. Water oxidation is also essential in artificial photosynthesis and solar fuel-forming reactions, such as water splitting into hydrogen and oxygen (2 H2O + 4 hν → O2 + 2 H2) or water reduction of CO2 to methanol (2 H2O + CO2 + 6 hν → CH3OH + 3/2 O2), or hydrocarbons, which could provide clean, renewable energy. The “blue ruthenium dimer,” cis,cis-[(bpy)2(H2O)RuIIIORuIII(OH2)(bpy)2]4+, was the first well characterized molecule to catalyze water oxidation. On the basis of recent insight into the mechanism, we have devised a strategy for enhancing catalytic rates by using kinetically facile electron-transfer mediators. Rate enhancements by factors of up to ≈30 have been obtained, and preliminary electrochemical experiments have demonstrated that mediator-assisted electrocatalytic water oxidation is also attainable.

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