scholarly journals A molecular tandem cell for efficient solar water splitting

2020 ◽  
Vol 117 (24) ◽  
pp. 13256-13260 ◽  
Author(s):  
Degao Wang ◽  
Jun Hu ◽  
Benjamin D. Sherman ◽  
Matthew V. Sheridan ◽  
Liang Yan ◽  
...  
Keyword(s):  
Water Splitting ◽  
Water Oxidation ◽  
Photoelectrochemical Cell ◽  
Applied Bias ◽  
Tandem Cell ◽  
Solar Water Splitting ◽  
Dye Sensitized ◽  
Solar Conversion ◽  
Artificial Photosynthetic ◽  
Natural Photosynthesis

Artificial photosynthesis provides a way to store solar energy in chemical bonds. Achieving water splitting without an applied external potential bias provides the key to artificial photosynthetic devices. We describe here a tandem photoelectrochemical cell design that combines a dye-sensitized photoelectrosynthesis cell (DSPEC) and an organic solar cell (OSC) in a photoanode for water oxidation. When combined with a Pt electrode for H2evolution, the electrode becomes part of a combined electrochemical cell for water splitting, 2H2O → O2+ 2H2, by increasing the voltage of the photoanode sufficiently to drive bias-free reduction of H+to H2. The combined electrode gave a 1.5% solar conversion efficiency for water splitting with no external applied bias, providing a mimic for the tandem cell configuration of PSII in natural photosynthesis. The electrode provided sustained water splitting in the molecular photoelectrode with sustained photocurrent densities of 1.24 mA/cm2for 1 h under 1-sun illumination with no applied bias.

scholarly journals Stabilization of a molecular water oxidation catalyst on a dye−sensitized photoanode by a pyridyl anchor

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Zhu ◽  
Degao Wang ◽  
Qing Huang ◽  
Jian Du ◽  
Licheng Sun ◽  
...  
Keyword(s):  
Water Splitting ◽  
Phosphonic Acid ◽  
Water Oxidation ◽  
Oxidation Catalyst ◽  
Molecular Water ◽  
Applied Bias ◽  
Surface Loading ◽  
Dye Sensitized ◽  
Monomeric Structure ◽  
Molecular Catalysts

Abstract Understanding and controlling the properties of water-splitting assemblies in dye-sensitized photoelectrosynthesis cells is a key to the exploitation of their properties. We demonstrate here that, following surface loading of a [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) chromophore on nanoparticle electrodes, addition of the molecular catalysts, Ru(bda)(L)2 (bda  =  2,2′-bipyridine-6,6′-dicarboxylate) with phosphonate or pyridyl sites for water oxidation, gives surfaces with a 5:1 chromophore to catalyst ratio. Addition of the surface-bound phosphonate derivatives with L = 4-pyridyl phosphonic acid or diethyl 3-(pyridin-4-yloxy)decyl-phosphonic acid, leads to well-defined surfaces but, following oxidation to Ru(III), they undergo facile, on-surface dimerization to give surface-bound, oxo-bridged dimers. The dimers have a diminished reactivity toward water oxidation compared to related monomers in solution. By contrast, immobilization of the Ru-bda catalyst on TiO2 with the 4,4′-dipyridyl anchoring ligand can maintain the monomeric structure of catalyst and gives relatively stable photoanodes with photocurrents that reach to 1.7 mA cm−2 with an optimized, applied bias photon-to-current efficiency of 1.5%.

scholarly journals Visible photoelectrochemical water splitting into H2 and O2 in a dye-sensitized photoelectrosynthesis cell

2015 ◽  
Vol 112 (19) ◽  
pp. 5899-5902 ◽  
Author(s):  
Leila Alibabaei ◽  
Benjamin D. Sherman ◽  
Michael R. Norris ◽  
M. Kyle Brennaman ◽  
Thomas J. Meyer
Keyword(s):  
Water Splitting ◽  
Single Molecule ◽  
Water Oxidation ◽  
Shell Thickness ◽  
Atomic Layer ◽  
Oxidation Catalyst ◽  
Core Shell ◽  
Hybrid Strategy ◽  
Solar Water Splitting ◽  
Dye Sensitized

A hybrid strategy for solar water splitting is exploited here based on a dye-sensitized photoelectrosynthesis cell (DSPEC) with a mesoporous SnO2/TiO2 core/shell nanostructured electrode derivatized with a surface-bound Ru(II) polypyridyl-based chromophore–catalyst assembly. The assembly, [(4,4’-(PO3H2)2bpy)2Ru(4-Mebpy-4’-bimpy)Ru(tpy)(OH2)]4+ ([RuaII-RubII-OH2]4+, combines both a light absorber and a water oxidation catalyst in a single molecule. It was attached to the TiO2 shell by phosphonate-surface oxide binding. The oxide-bound assembly was further stabilized on the surface by atomic layer deposition (ALD) of either Al2O3 or TiO2 overlayers. Illumination of the resulting fluorine-doped tin oxide (FTO)|SnO2/TiO2|-[RuaII-RubII-OH2]4+(Al2O3 or TiO2) photoanodes in photoelectrochemical cells with a Pt cathode and a small applied bias resulted in visible-light water splitting as shown by direct measurements of both evolved H2 and O2. The performance of the resulting DSPECs varies with shell thickness and the nature and extent of the oxide overlayer. Use of the SnO2/TiO2 core/shell compared with nanoITO/TiO2 with the same assembly results in photocurrent enhancements of ∼5. Systematic variations in shell thickness and ALD overlayer lead to photocurrent densities as high as 1.97 mA/cm2 with 445-nm, ∼90-mW/cm2 illumination in a phosphate buffer at pH 7.

3.17% efficient Cu2ZnSnS4–BiVO4 integrated tandem cell for standalone overall solar water splitting

2021 ◽  
Author(s):  
Dingwang Huang ◽  
Kang Wang ◽  
Lintao Li ◽  
Kuang Feng ◽  
Na An ◽  
...  
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Tandem Cell ◽  
Solar Water ◽  
Solar Water Splitting ◽  
First Time

3.17% efficient Cu2ZnSnS4–BiVO4 integrated tandem cell and a large scale 5 × 5 cm integrated CZTS–BiVO4 tandem device for standalone overall solar water splitting was assembled for the first time.

Electrodeposited Thin Conformal TiO2 Coating Enabling Stable Operation of BiVO4 Photoanodes in Basic Media

2018 ◽  
Vol MA2018-01 (31) ◽  
pp. 1917-1917
Author(s):  
Dongho Lee ◽  
Kyoung-Shin Choi
Keyword(s):  
Oxygen Evolution ◽  
Water Oxidation ◽  
Synthesis Method ◽  
Protective Layer ◽  
Photoelectrochemical Cell ◽  
Semiconductor Surface ◽  
Stable Operation ◽  
Solar Water Splitting ◽  
Wide Range ◽  
Basic Solutions

Producing hydrogen via solar water splitting using a photoelectrochemical cell (PEC) persists as one of the most exciting research topics in the field of solar fuels. The construction of efficient PECs requires the integration of multiple components including a photoanode, a photocathode, an oxygen evolution catalyst, and a hydrogen evolution catalyst. Therefore, the compatibility and stability of all of these elements in a given operating condition are crucial. When the stability of a semiconductor electrode used as the photoanode or photocathode is limited in an acidic or basic condition which is optimum for the operation of the other components, a thin protective layer has been deposited on the semiconductor surface to prevent its chemical dissolution. Surface coating of a thin and conformal TiO2 layer has been proven to be successful for protecting photoelectrodes since TiO2 is chemically and electrochemically stable in a wide range of pH conditions under both anodic and cathodic conditions. In order to prevent the semiconductor surface from coming into direct contact with the corrosive electrolyte, complete coverage of the photoelectrode with TiO2 is required. At the same time, the TiO2 layer should be thin enough not to interfere with the charge transport properties of the photoelectrode. As a result, atomic layer deposition (ALD) has been the only successful tool used to date to produce an effective protective layer. However, the slow processing time and economic viability of ALD methods motivated us to develop an inexpensive and facile solution-based synthesis method for the deposition of high quality TiO2 coating layers. In this presentation, we report a new electrochemical method to deposit a thin and conformal TiO2 layer on nanoporous BiVO4 that has an intricate, high surface area morphology. BiVO4 is a promising n-type photoanode material with a relatively low bandgap (2.4~2.5 eV). However, its usage has been limited to neutral and mildly basic conditions (pH 5~9) because it is chemically unstable in strongly acidic and basic conditions. Our method allows for the deposition of a 5~6 nm thick TiO2 layer on BiVO4 within 1 min and the resulting BiVO4/TiO2 electrodes exhibit chemical stability in basic solutions (pH 12~13). Sulfite oxidation measurements of BiVO4 and BiVO4/TiO2 electrodes show that the thin TiO2 protective layer does not significantly reduce the hole transfer to the electrolyte. Finally, we demonstrate the photoelectrochemical stability of the BiVO4/TiO2 electrode for photoelectrochemical water oxidation in basic solutions by coupling the BiVO4/TiO2 electrode with appropriate oxygen evolution catalysts.

Two photon tandem photoanode with black phosphorous quantum dot sensitized BiVO4 for solar water splitting

2022 ◽  
Author(s):  
Bingjun Jin ◽  
Yoonjun Cho ◽  
Cheolwoo Park ◽  
Jeehun Jeong ◽  
Sungsoon Kim ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Water Splitting ◽  
Water Oxidation ◽  
Oxidation Kinetics ◽  
Light Harvesting ◽  
Charge Recombination ◽  
Solar Water ◽  
Two Photon ◽  
Solar Water Splitting ◽  
Pec Water Splitting

The photoelectrochemical (PEC) water splitting efficiency is profoundly restricted by the limited light harvesting, rapid charge recombination, and sluggish water oxidation kinetics, in which the construction of a photoelectrode requires...

scholarly journals Integrated Membrane-Electrode-Assembly Photoelectrochemical Cell under Various Feed Conditions for Solar Water Splitting

2018 ◽  
Vol 166 (5) ◽  
pp. H3020-H3028 ◽  
Author(s):  
Tobias A. Kistler ◽  
David Larson ◽  
Karl Walczak ◽  
Peter Agbo ◽  
Ian D. Sharp ◽  
...  
Keyword(s):  
Water Splitting ◽  
Membrane Electrode Assembly ◽  
Photoelectrochemical Cell ◽  
Membrane Electrode ◽  
Solar Water ◽  
Solar Water Splitting

scholarly journals Ferroelectric Materials: A Novel Pathway for Efficient Solar Water Splitting

2018 ◽  
Vol 8 (9) ◽  
pp. 1526 ◽  
Author(s):  
Sangmo Kim ◽  
Nguyen Nguyen ◽  
Chung Bark
Keyword(s):  
Solar Energy ◽  
Water Splitting ◽  
Conversion Efficiency ◽  
Water Oxidation ◽  
Complex Structure ◽  
Ferroelectric Materials ◽  
Promising Candidate ◽  
Solar Water ◽  
Solar Water Splitting ◽  
The Past

Over the past few decades, solar water splitting has evolved into one of the most promising techniques for harvesting hydrogen using solar energy. Despite the high potential of this process for hydrogen production, many research groups have encountered significant challenges in the quest to achieve a high solar-to-hydrogen conversion efficiency. Recently, ferroelectric materials have attracted much attention as promising candidate materials for water splitting. These materials are among the best candidates for achieving water oxidation using solar energy. Moreover, their characteristics are changeable by atom substitute doping or the fabrication of a new complex structure. In this review, we describe solar water splitting technology via the solar-to-hydrogen conversion process. We will examine the challenges associated with this technology whereby ferroelectric materials are exploited to achieve a high solar-to-hydrogen conversion efficiency.

(Invited) Surface Modification of Dye-Sensitized Hydrogen-Evolving Photocatalyst for Z-Scheme Solar Water Splitting

2021 ◽  
Vol MA2021-01 (15) ◽  
pp. 696-696
Author(s):  
Atsushi Kobayashi ◽  
Nobutaka Yoshimura ◽  
Masaki Yoshida ◽  
Masako Kato
Keyword(s):  
Surface Modification ◽  
Water Splitting ◽  
Solar Water ◽  
Solar Water Splitting ◽  
Dye Sensitized
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