| 1. |
- Hou, Jungang, et al.
(författare)
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Atomically Thin Mesoporous In2O3-x/In2S3 Lateral Heterostructures Enabling Robust Broadband-Light Photo-Electrochemical Water Splitting
- 2018
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Ingår i: Advanced Energy Materials. - : Wiley-VCH Verlagsgesellschaft. - 1614-6832 .- 1614-6840. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- Atomically thin 2D heterostructures have opened new realms in electronic and optoelectronic devices. Herein, 2D lateral heterostructures of mesoporous In2O3-x/In2S3 atomic layers are synthesized through the in situ oxidation of In2S3 atomic layers by an oxygen plasma-induced strategy. Based on experimental observations and theoretical calculations, the prolonged charge carrier lifetime and increased electron density reveal the efficient photoexcited carrier transport and separation in the In2O3-x/In2S3 layers by interfacial bonding at the atomic level. As expected, the synergistic structural and electronic modulations of the In2O3-x/In2S3 layers generate a photocurrent of 1.28 mA cm(-2) at 1.23 V versus a reversible hydrogen electrode, nearly 21 and 79 times higher than those of the In2S3 atomic layers and bulk counterpart, respectively. Due to the large surface area, abundant active sites, broadband-light harvesting ability, and effective charge transport pathways, the In2O3-x/In2S3 layers build efficient pathways for photoexcited charge in the 2D semiconductive channels, expediting charge transport and kinetic processes and enhancing the robust broadband-light photo-electrochemical water splitting performance. This work paves new avenues for the exploration and design of atomically thin 2D lateral heterostructures toward robust photo-electrochemical applications and solar energy utilization.
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| 2. |
- Hou, Jungang, et al.
(författare)
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Electrical Behavior and Electron Transfer Modulation of Nickel-Copper Nanoalloys Confined in Nickel-Copper Nitrides Nanowires Array Encapsulated in Nitrogen-Doped Carbon Framework as Robust Bifunctional Electrocatalyst for Overall Water Splitting
- 2018
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 28:37
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Tidskriftsartikel (refereegranskat)abstract
- Probing robust electrocatalysts for overall water splitting is vital in energy conversion. However, the catalytic efficiency of reported catalysts is still limited by few active sites, low conductivity, and/or discrete electron transport. Herein, bimetallic nickel-copper (NiCu) nanoalloys confined in mesoporous nickel-copper nitride (NiCuN) nanowires array encapsulated in nitrogen-doped carbon (NC) framework (NC-NiCu-NiCuN) is constructed by carbonization-/nitridation-induced in situ growth strategies. The in situ coupling of NiCu nanoalloys, NiCuN, and carbon layers through dual modulation of electrical behavior and electron transfer is not only beneficial to continuous electron transfer throughout the whole system, but also promotes the enhancement of electrical conductivity and the accessibility of active sites. Owing to strong synergetic coupling effect, such NC-NiCu-NiCuN electrocatalyst exhibits the best hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance with a current density of 10 mA cm(-2) at low overpotentials of 93 mV for HER and 232 mV for OER, respectively. As expected, a two-electrode cell using NC-NiCu-NiCuN is constructed to deliver 10 mA cm(-2) water-splitting current at low cell voltage of 1.56 V with remarkable durability over 50 h. This work serves as a promising platform to explore the design and synthesis of robust bifunctional electrocatalyst for overall water splitting.
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| 3. |
- Hou, Jungang, et al.
(författare)
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Promoting Active Sites in Core-Shell Nanowire Array as Mott-Schottky Electrocatalysts for Efficient and Stable Overall Water Splitting
- 2018
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 28:4
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Tidskriftsartikel (refereegranskat)abstract
- Developing earth-abundant, active, and robust electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains a vital challenge for efficient conversion of sustainable energy sources. Herein, metal-semiconductor hybrids are reported with metallic nanoalloys on various defective oxide nanowire arrays (Cu/CuOx, Co/CoOx, and CuCo/CuCoOx) as typical Mott-Schottky electrocatalysts. To build the highway of continuous electron transport between metals and semiconductors, nitrogen-doped carbon (NC) has been implanted on metal-semiconductor nanowire array as core-shell conductive architecture. As expected, NC/CuCo/CuCoOx nanowires arrays, as integrated Mott-Schottky electrocatalysts, present an overpotential of 112 mV at 10 mA cm(-2) and a low Tafel slope of 55 mV dec(-1) for HER, simultaneously delivering an overpotential of 190 mV at 10 mA cm(-2) for OER. Most importantly, NC/CuCo/CuCoOx architectures, as both the anode and the cathode for overall water splitting, exhibit a current density of 10 mA cm(-2) at a cell voltage of 1.53 V with excellent stability due to high conductivity, large active surface area, abundant active sites, and the continuous electron transport from prominent synergetic effect among metal, semiconductor, and nitrogen-doped carbon. This work represents an avenue to design and develop efficient and stable Mott-Schottky bifunctional electrocatalysts for promising energy conversion.
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| 4. |
- Hou, Jungang, et al.
(författare)
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Vertically Aligned Oxygenated-CoS2-MoS2 Heteronanosheet Architecture from Polyoxometalate for Efficient and Stable Overall Water Splitting
- 2018
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Ingår i: ACS Catalysis. - : AMER CHEMICAL SOC. - 2155-5435. ; 8:5, s. 4612-4621
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Tidskriftsartikel (refereegranskat)abstract
- To achieve efficient conversion of renewable energy sources through water splitting, low-cost, earth-abundant, and robust electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are required. Herein, vertically aligned oxygenated-CoS2-MoS2 (O-CoMoS) heteronanosheets grown on flexible carbon fiber cloth as bifunctional electrocatalysts have been produced by use of the Anderson-type (NH4)(4)[CoIIMo(6)O(2)4H(6)]center dot 6H(2)O polyoxometalate as bimetal precursor. In comparison to different O-FeMoS, O-NiMoS, and MoS2 nanosheet arrays, the O-CoMoS heteronanosheet array exhibited low overpotentials of 97 and 272 mV to reach a current density of 10 mA cm(-2) in alkaline solution for the HER and OER, respectively. Assembled as an electrolyzer for overall water splitting, O-CoMoS heteronanosheets as both the anode and cathode deliver a current density of 10 mA cm(-2) at a quite low cell voltage of 1.6 V. This O-CoMoS architecture is highly advantageous for a disordered structure, exposure of active heterointerfaces, a "highway" of charge transport on two-dimensional conductive channels, and abundant active catalytic sites from the synergistic effect of the heterostructures, accomplishing a dramatically enhanced performance for the OER, HER, and overall water splitting. This work represents a feasible strategy to explore efficient and stable bifunctional bimetal sulfide electrocatalysts for renewable energy applications.
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| 5. |
- Wu, Yunzhen, et al.
(författare)
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Orienting Active Crystal Planes of New Class Lacunaris Fe2PO5 Polyhedrons for Robust Water Oxidation in Alkaline and Neutral Media
- 2018
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 28:35
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Tidskriftsartikel (refereegranskat)abstract
- Developing efficient and stable oxygen evolution reaction (OER) electrocatalysts is essential for realizing sustainable energy conversion, such as solar fuels. Although modulating active sites and electron transfer is of great significance to boost electrocatalysis activity, it still remains a big challenge to desirably actualize this goal. Herein, engineering of active sites and electronic framework is implemented via oriented modulation of crystal planes and construction of lacunaris architecture supported by ammonification-elicited simultaneous incorporation of nitrogen and oxygen-defect strategy. The new class porous nitrogen-incorporated Fe2PO5 with oxygen-defect (N-Fe2PO5-x) polyhedron with dominantly exposed {110} reactive facets exhibits superior performance toward water oxidation, achieving current densities of 10 mA cm(-2) at quite low overpotentials of 235 and 315 mV in alkaline and neutral media, respectively. Furthermore, density functional theoretical calculations reveal the energetically favorable {110} planes of lower absorption energy of intermediates and remolding of electronic density framework arising from the ammoniated elicitation process, contributing to excellent OER performance of lacunaris N-Fe2PO5-x polyhedrons. This work may offer a feasible guideline for regulating active sites and electron transfer to develop low-cost and highly efficient OER electrocatalysts in energy conversion systems.
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| 6. |
- Ye, Lu, et al.
(författare)
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Assembly of highly efficient photocatalytic CO2 conversion systems with ultrathin two-dimensional metal-organic framework nanosheets
- 2018
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Ingår i: Applied Catalysis B. - : ELSEVIER SCIENCE BV. - 0926-3373 .- 1873-3883. ; 227, s. 54-60
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Tidskriftsartikel (refereegranskat)abstract
- An ultrathin two-dimensional Zn porphyrin-based metal-organic framework (Zn-MOF nanosheets) is developed and used for the first time in photoreduction of CO2 to CO. Consequently, two novelty noble-metal-free hybrid photocatalytic systems are established and displayed outstanding photocatalytic activity and selectivity for CO evolution under mild photocatalytic reaction conditions. The insight revealed Zn-MOF nanosheets as photo sensitizer displays a better charge transport ability and longer lifetime of the photogenerated electron-hole pairs than the Zn-MOF bulk, which are confirmed by photoelectrochemical impedance and photoluminescence (PL) measurements. These studies show that the development of noble-metal-free photocatalytic systems and various MOF-based materials for photocatalytic applications are promising.
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