| 1. |
- Fan, Zhaozhong, et al.
(författare)
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Oxygen-Bridged Indium-Nickel Atomic Pair as Dual-Metal Active Sites Enabling Synergistic Electrocatalytic CO2 Reduction
- 2023
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 62:7
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Tidskriftsartikel (refereegranskat)abstract
- Single-atom catalysts offer a promising pathway for electrochemical CO2 conversion. However, it is still a challenge to optimize the electrochemical performance of dual-atom catalysts. Here, an atomic indium-nickel dual-sites catalyst bridged by an axial oxygen atom (O-In-N6-Ni moiety) was anchored on nitrogenated carbon (InNi DS/NC). InNi DS/NC exhibits superior CO selectivity with Faradaic efficiency higher than 90 % over a wide potential range from −0.5 to −0.8 V versus reversible hydrogen electrode (vs. RHE). Moreover, an industrial CO partial current density up to 317.2 mA cm−2 is achieved at −1.0 V vs. RHE in a flow cell. In situ ATR-SEIRAS combined with theory calculations reveal that the synergistic effect of In-Ni dual-sites and O atom bridge not only reduces the reaction barrier for the formation of *COOH, but also retards the undesired hydrogen evolution reaction. This work provides a feasible strategy to construct dual-site catalysts towards energy conversion.
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| 2. |
- He, Xiaoyu, et al.
(författare)
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Dual-optimization strategy engineered Ti-based metal-organic framework with Fe active sites for highly-selective CO2 photoreduction to formic acid
- 2023
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Ingår i: Applied Catalysis B. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 327
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Tidskriftsartikel (refereegranskat)abstract
- Increasing CO2 conversion efficiency over metal-organic framework (MOF) based photocatalysts is of great significance to promote the carbon capture and utilization. In this work, a dual-benefit design strategy is deployed in the synthesis of a new two-dimensional Fe/Ti-BPDC MOF photocatalyst with atomically dispersed Fe sites. This catalyst demonstrated an excellent catalytic performance in the visible-light-driven CO2 conversion to HCOOH, achieving a high yield of 703.9 μmol g-1 h-1 at a selectivity greater than 99.7%. This is attributed to the ‘dual-optimization’ achieved by this catalyst to sustain the supply of photogenerated electrons and to effectively activate CO2. Specifically, the Fe/Ti-BPDC catalyst provides a high proportion of effective photogenerated electrons for the CO2 photocatalysis process via a unique electron transfer mechanism. Meanwhile, the strong O/Fe affinity between CO2 and atomically dispersed Fe active sites not only enables a fast CO2 activation, but also dictates the intermediate reaction pathways towards high HCOOH selectivity.
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| 3. |
- Hou, Jungang, et al.
(författare)
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Active Sites Intercalated Ultrathin Carbon Sheath on Nanowire Arrays as Integrated Core-Shell Architecture : Highly Efficient and Durable Electrocatalysts for Overall Water Splitting
- 2017
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Ingår i: Small. - : Wiley-VCH Verlagsgesellschaft. - 1613-6810 .- 1613-6829. ; 13:46
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Tidskriftsartikel (refereegranskat)abstract
- The development of active bifunctional electrocatalysts with low cost and earth-abundance toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains a great challenge for overall water splitting. Herein, metallic Ni4Mo nanoalloys are firstly implanted on the surface of NiMoOx nanowires array (NiMo/NiMoOx) as metal/metal oxides hybrid. Inspired by the superiority of carbon conductivity, an ultrathin nitrogen-doped carbon sheath intercalated NiMo/NiMoOx (NC/NiMo/NiMoOx) nanowires as integrated core-shell architecture are constructed. The integrated NC/NiMo/NiMoOx array exhibits an overpotential of 29 mV at 10 mA cm(-2) and a low Tafel slope of 46 mV dec(-1) for HER due to the abundant active sites, fast electron transport, low charge-transfer resistance, unique architectural structure and synergistic effect of carbon sheath, nanoalloys, and oxides. Moreover, as OER catalysts, the NC/NiMo/NiMoOx hybrids require an overpotential of 284 mV at 10 mA cm(-2). More importantly, the NC/NiMo/NiMoOx array as a highly active and stable electrocatalyst approaches approximate to 10 mA cm(-2) at a voltage of 1.57 V, opening an avenue to the rational design and fabrication of the promising electrode materials with architecture structures toward the electrochemical energy storage and conversion.
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| 4. |
- 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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| 5. |
- 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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| 6. |
- Hou, Jungang, et al.
(författare)
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Graphene Dots Embedded Phosphide Nanosheet-Assembled Tubular Arrays for Efficient and Stable Overall Water Splitting
- 2017
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 9:29, s. 24600-24607
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Tidskriftsartikel (refereegranskat)abstract
- Bifunctional electrocatalysts are highly desired for overall water splitting. Herein, the design and fabrication of three-dimensional (3D) hierarchical earth-abundant transition bimetallic phosphide arrays constructed by one-dimensional tubular array that was derived from assembling two-dimensional nanosheet framework has been reported by tailoring the Co/Ni ratio and tunable morphologies, and zero-dimensional (0D) graphene dots were embedded on Co-Ni phosphide matrix to construct 0D/2D tubular array as a highly efficient electrode in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). On the basis of advanced merits, such as the high surface-active sites, well-dispersed graphene dots, and enhanced electron transfer capacity as well as the confinement effect of the graphene dots on the nanosheets, the integrated GDs/Co0.8Ni0.2P tubular arrays as anode and cathode exhibit excellent OER and HER performance. By use of GDs/Co0.8Ni0.2 arrays in the two-electrode setup of the device, a remarkable electrocatalytic performance for full water splitting has been achieved with a high current density of 10 mA cm-2 at 1.54 V and outstanding long-term operation stability in an alkaline environment, indicating a promising system based on nonprecious-metal electrocatalysts toward potential practical devices of overall water splitting.
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| 7. |
- Hou, Jungang, et al.
(författare)
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In Situ Phase-Induced Spatial Charge Separation in Core-Shell Oxynitride Nanocube Heterojunctions Realizing Robust Solar Water Splitting
- 2017
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Ingår i: Advanced Energy Materials. - : WILEY-V C H VERLAG GMBH. - 1614-6832 .- 1614-6840. ; 7:17
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Tidskriftsartikel (refereegranskat)abstract
- Efficient spatial charge separation is critical for solar energy conversion over solid photocatalysts. The development of efficient visible-light photocatalysts has been of immense interest, but with limited success. Here, multiband core-shell oxynitride nanocube heterojunctions composed of a tantalum nitride (Ta3N5) core and nitrogen-doped sodium tantalate (NaTaON) shell have been constructed via an in situ phase-induced etching chemical strategy. The photocatalytic water splitting performance of sub-20-nm Ta3N5@NaTaON junctions exhibits an extraordinarily high photocatalytic activity toward oxygen and hydrogen evolution. Most importantly, the combined experimental results and theoretical calculations reveal that the strong interfacial Ta-O-N bonding connection as a touchstone among Ta3N5@NaTaON junctions provides a continuous charge transport pathway rather than a random charge accumulation. The prolonged photoexcited charge carrier lifetime and suitable band matching between the Ta3N5 core and NaTaON shell facilitate the separation of photoinduced electron-hole pairs, accounting for the highly efficient photocatalytic performance. This work establishes the use of (oxy)nitride heterojunctions as viable photocatalysts for the conversion of solar energy into fuels.
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| 8. |
- Hou, Jungang, et al.
(författare)
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Inorganic Colloidal Perovskite Quantum Dots for Robust Solar CO2 Reduction
- 2017
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Ingår i: Chemistry - A European Journal. - : Wiley-VCH Verlagsgesellschaft. - 0947-6539 .- 1521-3765. ; 23:40, s. 9481-9485
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Tidskriftsartikel (refereegranskat)abstract
- Inorganic perovskite quantum dots as optoelectronic materials have attracted enormous attention in light-harvesting and emitting devices. However, photocatalytic conversion based on inorganic perovskite halides has not been reported. Here, we have synthesized colloidal quantum dots (QDs, 3-12 nm) of cesium lead halide perovskites (CsPbBr3) as a new type of photocatalytic material. The band gap energies and photoluminescence (PL) spectra are tunable over the visible spectral region according to quantum size effects on an atomic scale. The increased carrier lifetime revealed by time-resolved PL spectra, indicates the efficient electron-hole separation and transfer. As expected, the CsPbBr3 QDs with high selectivity of greater than 99% achieve an efficient yield of 20.9 mmolg(-1) towards solar CO2 reduction. This work has opened a new avenue for inorganic colloidal perovskite materials as efficient photocatalysts to convert CO2 into valuable fuels.
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| 9. |
- 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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| 10. |
- Hou, Jungang, et al.
(författare)
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Rational Design of Nanoarray Architectures for Electrocatalytic Water Splitting
- 2019
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 29:20
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Forskningsöversikt (refereegranskat)abstract
- Electrochemical water splitting is recognized as a practical strategy for impelling the transformation of sustainable energy sources such as solar energy from electricity to clean hydrogen fuel. To actualize the large-scale hydrogen production, it is paramount to develop low-cost, earth-abundant, efficient, and stable electrocatalysts. Among those electrocatalysts, alternative architectural arrays grown on conductive substrates have been proven to be highly efficient toward water splitting due to large surface area, abundant active sites, and synergistic effects between the electrocatalysts and the substrates. Herein, the advancement of nanoarray architectures in electrocatalytic applications is reviewed. The categories of different nanoarrays and the reliable and versatile synthetic approaches of electrocatalysts are summarized. A unique emphasis is highlighted on the promising strategies to enhance the electrocatalytic activities and stability of architectural arrays by component manipulation, heterostructure regulation, and vacancy engineering. The intrinsic mechanism analysis of electronic structure optimization, intermediates' adsorption facilitation, and coordination environments' amelioration is also discussed with regard to theoretical simulation and in situ identification. Finally, the challenges and opportunities on the valuable directions and promising pathways of architectural arrays toward outstanding electrocatalytic performance are provided in the energy conversion field, facilitating the development of promising water splitting systems.
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