Stable p‐type Cu:CdS1−xSex/Pt Thin‐Film Photocathodes with Fully Tunable Bandgap for Scavenger‐Free Photoelectrochemical Water Splitting

Ye, Zi; Hu, Zhuofeng; Yang, Lixia; Xiao, Xudong

doi:10.1002/solr.201900567

Cited by 13 publications

(4 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14 While the most-investigated photovoltaic materials (Si, III-Vs, and II-VI compounds) have promising properties for PEC applications, all corrode rapidly under electrochemical operation, a result of their low Pourbaix stability. 7,[15][16][17] Substantial efforts have been dedicated to limiting such corrosion, 18,19 but these have failed to generate photoelectrodes with surfaces which are durable for more than tens of hours of operation. While these issues can be partially addressed via application of a protection layer, such approaches are undesirable due to complex processing 20 and the propensity for degradation from electrolyte infiltration at pinholes or grain boundaries.…”

Section: Introductionmentioning

confidence: 99%

Zinc Titanium Nitride Semiconductor toward Durable Photoelectrochemical Applications

Greenaway

Culman

et al. 2022

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Photoelectrochemical fuel generation is a promising route to sustainable liquid fuels produced from water and captured carbon dioxide with sunlight as the energy input. Development of such technologies requires photoelectrode materials that are both photocatalytically active and operationally stable in harsh oxidative and/or reductive electrochemical environments. Such photocatalysts can be discovered based on co-design principles, wherein design for stability is based on the propensity for the photocatalyst to self-passivate under operating conditions and design for photoactivity is based on the ability to integrate the photocatalyst with established semiconductor substrates. Here we report on synthesis and characterization of zinc titanium nitride (ZnTiN 2 ) that follows these design rules by having a wurtzite-derived crystal structure and showing self-passivating surface oxides created by electrochemical polarization. The sputtered ZnTiN 2 thin films have optical absorption onsets below 2 eV and n-type electrical conduction of 0.1 S/cm. The band gap of this material is reduced from the 3.5 eV theoretical value by cation site disorder, and the impact of cation antisites on the band structure of ZnTiN 2 is explored using density functional theory. Under electrochemical polarization, the ZnTiN 2 surfaces have TiO 2 -or ZnO-like character, consistent with Materials Project Pourbaix calculations predicting the formation of stable solid phases under near-neutral pH. These results show that ZnTiN 2 is a promising candidate for photoelectrochemical liquid fuel generation and demonstrate a new materials design approach to other photoelectrodes with self-passivating native operational surface chemistry. Broader ImpactPhotoelectrochemical fuel generation has been stymied by a lack of photoelectrode materials which are both highly active and stable under long-term operation. Searches for new photoelectrodes have typically selected either stability or activity, with the intent to improve the other characteristic after the fact. Inspired by technologies that employ designed surface transformations for operational stability, such as the precipitation strengthening of Ni-based superalloys in gas turbines, here we employ co-design principles to identify a candidate photoelectrode material which can fill both stability and activity requirements. We synthesize this promising candidate photoelectrode material, ZnTiN2, which forms stable protective oxides under electrochemical operation, providing a route to stability, while being structurally compatible with established semiconductors, enabling good optoelectronic properties. We investigate the optoelectronic properties and electrochemical stability of ZnTiN2 both experimentally and computationally. These results confirm the promise of ZnTiN2 as a photoelectrode material and point to a successful new materials design strategy for photoelectrode development.

show abstract

Section: Introductionmentioning

confidence: 99%

Zinc Titanium Nitride Semiconductor toward Durable Photoelectrochemical Applications

Greenaway

Culman

et al. 2022

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…degrade under most illuminated, aqueous electrochemical conditions, especially as photocathodes. [6,[14][15][16][17] Protection schemes for PEC electrodes require a layer that (1) has minimal parasitic absorption above the semiconductor bandgap; (2) facilitates charge transfer to and from solution; and (3) prevents direct interaction of the electrolyte with the semiconductor, minimizing deleterious, non-fuel-forming reactions. These criteria have led to a proliferation of protection strategies that have been well-reviewed in the literature.…”

Section: Introductionmentioning

confidence: 99%

“…While the design of new semiconductors that do not degrade under operation remains attractive, [12,13] the highly optimized semiconductors deployed in PV (e. g. Si, III‐Vs, etc.) degrade under most illuminated, aqueous electrochemical conditions, especially as photocathodes [6,14–17] . Protection schemes for PEC electrodes require a layer that (1) has minimal parasitic absorption above the semiconductor bandgap; (2) facilitates charge transfer to and from solution; and (3) prevents direct interaction of the electrolyte with the semiconductor, minimizing deleterious, non‐fuel‐forming reactions.…”

Section: Introductionmentioning

confidence: 99%

Transparent Conductive Encapsulants for Photoelectrochemical Applications

et al. 2023

View full text Add to dashboard Cite

Utilizing sunlight to directly perform photoelectrochemical reactions is a promising route to renewable, net carbon‐neutral fuels. However, a common problem with solar fuel production is semiconductor degradation in aqueous environments. An ideal protection layer should (1) prevent solution from reaching the semiconductor, (2) maintain charge transfer to and from solution, and (3) be transparent to light above the semiconductor band gap. While there have been substantial advances toward layers that meet these requirements, they are not easily adapted to new surfaces or new reactions, which can make protection difficult for newly developed photoabsorbers and (photo)electrochemical reaction pairings. In this work, we demonstrate the use of transparent conductive encapsulants (TCEs) to meet these requirements while also allowing for photoelectrode‐ and reaction‐agnostic adaptability. TCEs are composed of an ethyl‐vinyl acetate matrix with embedded conductive metal‐coated microspheres that can be laminated to semiconductors. First, the electrochemical behavior of TCE‐coated electrodes for the reduction of methyl viologen is characterized, demonstrating through‐TCE electrical conduction. Then, photoelectrochemical measurements on TCE‐protected semiconductors demonstrate the flexibility of this protection scheme. Finally, long‐term photoelectrochemical measurements probe the efficacy of TCEs as protection layers. These findings demonstrate the potential of TCEs as adaptable protection layers in various photoelectrochemical applications.

show abstract

“…Combining sunlight with the conventional electrolysis method can improve this process environmentally. [1][2][3] This technology is called photoelectrochemical (PEC), whereby, the photoelectrode utilizes photonic energy to split water in this technique. Semiconductors can convert the solar light energy to the electrical potential that can be used for dissociating water molecules in the PEC technology.…”

mentioning

confidence: 99%

A New Photoelectrochemical Reactor with Special Photocathode Design for Hydrogen Production

Ismael

Dinçer

2022

Adv Eng Mater

View full text Add to dashboard Cite

Population inflation and life development are leading to increased world energy needs. In addition, fossil fuel resources are depleting dramatically, including oil, natural gas, and coal. The global carbon dioxide concentration is rising with the increase in energy usage. Thus, researchers seek to find alternative energy resources to overcome global warming issues and cover the gap in energy demands. Hydrogen is one of the main inexhaustible constituents in the universe, making it a potential fuel for the future. It has a friendly environmental impact during its combustion and that makes it a green fuel. Although hydrogen is not independently available in the universe to deploy, it can only be generated by applying various methods and technologies from water. Electrolysis technology is a commonly favorable technique used for splitting water to produce hydrogen. Combining sunlight with the conventional electrolysis method can improve this process environmentally. [1][2][3] This technology is called photoelectrochemical (PEC), whereby, the photoelectrode utilizes photonic energy to split water in this technique. Semiconductors can convert the solar light energy to the electrical potential that can be used for dissociating water molecules in the PEC technology. [4] The needed hypothetical potential to dissociate water bonds into hydrogen and oxygen gases is 1.23 V. [5] The photoelectrode presents the major component in the PEC technology by generating an electric potential to contribute to the total potential required for the water dissociation. However, this technology still needs further development to be cost effective and efficient.Many types of photoelectrodes have been investigated and developed for improving the PEC process, such as type p, type n, and type n-p. [6] Furthermore, various semiconductors have been studied to improve the process of photoelectrolysis, including SiC, TiO 2 , Cu 2 O, WO 3 , ZnO, SnO 2 , CdS, MoS 2 , and BiVO 4 , liable on the application and conditions of the hydrogen production process. [7][8][9][10][11][12] Also, some perovskite oxides have been utilized to show the enhanced performance, high active, and durable catalysts for watersplitting such as NdBaMn 2 O 5.5 . [13] In addition, nonprecious catalysts have been studied and reviewed for the alkaline water electrolysis process. [14] Researchers have investigated and developed cuprous oxide (Cu 2 O) in many studies as one of the desirable catalysts for coating the photocathode of the PEC applications. [15,16] In addition, titanium-dioxide semiconductor (TiO 2 ) is considered the most favorable material that can be used to coat the anode due to its behavior to resist corrosion. [17,18] The electrodeposition method is considered a cheap technology utilized to prepare the cuprous oxide photocatalyst and coat the stainless-steel mesh dome cathode. [19] The electrodeposition conditions of the Cu 2 O photocatalysts have significant impacts on the crystal size, surface morphology, and photocatalysis properties. [20] The electrodeposition...

show abstract

Stable p‐type Cu:CdS_1−xSe_x/Pt Thin‐Film Photocathodes with Fully Tunable Bandgap for Scavenger‐Free Photoelectrochemical Water Splitting

Cited by 13 publications

References 48 publications

Zinc Titanium Nitride Semiconductor toward Durable Photoelectrochemical Applications

Zinc Titanium Nitride Semiconductor toward Durable Photoelectrochemical Applications

Transparent Conductive Encapsulants for Photoelectrochemical Applications

A New Photoelectrochemical Reactor with Special Photocathode Design for Hydrogen Production

Contact Info

Product

Resources

About