| 1. |
- Li, Fusheng, 1985-, et al.
(author)
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Electroless Plating of NiFeP Alloy on the Surface of Silicon Photoanode for Efficient Photoelectrochemical Water Oxidation
- 2020
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In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 12:10, s. 11479-11488
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Journal article (peer-reviewed)abstract
- N- type silicon is a kind of semiconductor with a narrow band gap that has been reported as an outstanding light-harvesting material for photoelectrochemical (PEC) reactions. Decorating a thin catalyst layer on the n-type silicon surface can provide a direct and effective route toward PEC water oxidation. However, most of catalyst immobilization methods for reported n-type silicon photoanodes have been based on energetically demanding, time-consuming, and high-cost processes. Herein, a high-performance NiFeP alloy (NiFeP)-decorated n-type micro-pyramid silicon array (n-Si) photoanode (NiFeP/n-Si) was prepared by a fast and low-cost electroless deposition method for light-driven water oxidation reaction. The saturated photocurrent density of NiFeP/n-Si can reach up to similar to 40 mA cm(-2) and a photocurrent density of 15.5 mA cm(-2) can be achieved at 1.23 V-RHE under light illumination (100 mW cm(-2), AM1.5 filter), which is one of the most promising silicon-based photoanodes to date. The kinetic studies showed that the NiFeP on the silicon photoanodes could significantly decrease the interfacial charge recombination between the n-type silicon surface and electrolyte.
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| 2. |
- Liu, Chang, et al.
(author)
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A dendritic Sb2Se3/In2S3 heterojunction nanorod array photocathode decorated with a MoSx catalyst for efficient solar hydrogen evolution
- 2020
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In: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:44, s. 23385-23394
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Journal article (peer-reviewed)abstract
- Developing cost-effective photocathodes that show desirable performance for use in commercial photoelectrochemical water splitting devices remains a fundamental and practical challenge. Sb2Se3 semiconductors satisfy most of the demands expected for an ideal highly efficient photocathode, including favorable cost and optoelectronic properties. Herein, we have demonstrated outstanding photoelectrodes using a noble-metal-free catalyst, namely, a MoSx-decorated low-cost Sb2Se3/In2S3 heterojunction, as the photocathode. This enabled a maximum photocurrent density of up to -27 mA cm(-2) (0 V vs. RHE, 100 mW cm(-2), AM 1.5G filter) with a remarkable half solar-to-hydrogen conversion efficiency (STH) of 2.6%, obtained via decreasing charge recombination and accelerating charge transfer through morphological optimization of the In2S3 layer.
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| 3. |
- Ma, Shengyu, et al.
(author)
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Metal–Molybdenum Sulfide Nanosheet Arrays Prepared by Anion Exchange as Catalysts for Hydrogen Evolution
- 2020
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In: Energy Technology. - : Wiley-VCH Verlag. - 2194-4288 .- 2194-4296. ; 8:10
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Journal article (peer-reviewed)abstract
- Metal–molybdenum sulfide (MMoSx)-based catalysts exhibit good performance over a wide pH range toward hydrogen evolution with relatively low overvoltage requirements. Therefore, they are considered as suitable alternatives to Pt as catalysts for hydrogen evolution reaction. Herein, self-supported amorphous CuMoSx and NiMoSx nanosheet arrays are prepared on copper foam (CF) and nickel foam (NF), respectively, through an anion-exchange strategy. CF and NF are first converted into CuTCNQ and NiTCNQ nanowire arrays (TCNQ = tetracyanoquinodimethane), which are then in situ reacted with (NH4)2MoS4 solution to generate amorphous CuMoSx/CF and NiMoSx/NF nanosheets, respectively, as efficient electrocatalysts for H2 generation. NiMoSx/NF exhibits a superior catalytic activity to CuMoSx/CF in 0.5 m H2SO4 solution, as CuMoSx/CF requires overpotentials (η) of 213 and 275 mV to obtain current densities of 10 and 50 mA cm−2, respectively, whereas NiMoSx/NF only requires η of 174 and 248 mV to receive the same current densities, respectively. Furthermore, these electrodes exhibit considerable long-term electrochemical durability. Herein, an effective and easy-to-operate strategy for the construction of self-supported metal–molybdenum sulfide nanosheet arrays films toward a highly efficient electrochemical hydrogen generation reaction is provided.
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| 4. |
- Zhou, Dinghua, et al.
(author)
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In Situ Induced Crystalline-Amorphous Heterophase Junction by K+ to Improve Photoelectrochemical Water Oxidation of BiVO4
- 2021
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In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:2, s. 2723-2733
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Journal article (peer-reviewed)abstract
- Solar water splitting is one of the most efficient technologies to produce H-2, which is a clean and renewable energy carrier. Photoanodes for water oxidation play the determining roles in solar water splitting, while its photoelectrochemical (PEC) performance is severely limited by the hole injection efficiency at the interface of semiconductor/electrolyte. To address this problem, in this research, by employing BiVO4 as the model semiconductor for photoanodes, we develop a novel, facile, and efficient method, which simply applies K cations in the preparation process of BiVO4 photoanodes, to in situ induce a crystalline-amorphous heterophase junction by the formation of an amorphous BiVO4 layer (a-BiVO4) on the surface of the crystalline BiVO4 (c-BiVO4) film for PEC water oxidation. The K cation is the key to stimulate the formation of the heterophase, but not incorporated in the final photoelectrodes. Without sacrificing the light absorption, the in situ formed a-BiVO4 layer accelerates the kinetics of the hole tranfer at the photoanode/electrolyte interface, leading to the significantly increased efficiency of the surface hole injection to water molecules. Consequently, the BiVO4 photoanode with the crystalline-amorphous heterophase junction (a-BiVO4/c-BiVO4) exhibits almost twice the photocurrent density at 1.23 V (vs reversible hydrogen electrode) for water oxidation than the bare c-BiVO4 ones. Such advantages from the crystalline-amorphous heterophase junction are still effective even when the a-BiVO4/c-BiVO4 is coated by the cocatalyst of FeOOH, reflecting its broad applications in PEC devices. We believe this study can supply an efficient and simple protocol to enhance the PEC water oxidation performance of photoanodes, and provide a new strategy for the potential large-scale application of the solar energy-conversion related devices.
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| 5. |
- Zhou, Dinghua, et al.
(author)
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WO3 Nanosheet-Supported IrW Alloy for High-Performance Acidic Overall Water Splitting with Low Ir Loading
- 2022
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In: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 5:1, s. 970-980
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Journal article (peer-reviewed)abstract
- Precious metals (like Ir, Ru, and Pt) and their derivatives are the benchmark catalysts for water splitting in acidic media due to their high stability and activity. However, the high cost and scarcity of these materials hamper the large-scale applications. To solve this issue, construction of catalysts containing low content of precious metals with high intrinsic activity can be an efficient strategy, which expectedly can decrease the cost but meanwhile preserve the activity. Herein, we synthesized an IrW/WO3 array catalyst by in situ formation of IrW alloy on hierarchical WO3 nanosheet arrays. With extremely low Ir content of 1.25 wt % in 0.5 M H2SO4, this composite catalyst not only shows superior water oxidation activity (the overpotential at 10 mA cm-2 is only 229 mV, significantly lower than that of the commercial IrO2 (358 mV)) but also exhibits excellent proton reduction performance (the overpotential at -10 mA cm-2 is 49 mV, close to that of commercial Pt/C catalyst (42 mV)), showing promising bifunctionality for the overall water splitting. As a result, only 1.5 V is needed to drive the overall water splitting at 10 mA cm-2 with a good long-term stability under acidic conditions. These remarkable features can be ascribed to the abundant active sites exposed by the three-dimensional nanostructure, and the high intrinsic activity per Ir site. The theoretical calculation verifies that Ir sites in IrW surface after oxidation have a higher intrinsic activity than IrO2 for water oxidation. We believe this research can supply a strategy to design highly active and stable catalysts with low loading of noble metals for acidic water splitting.
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