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991.
Hayeong Kim Sa-Rang Bae Tae Hyung Lee Hyoseong Lee Heemin Kang Sungnam Park Ho Won Jang Soo Young Kim 《Advanced functional materials》2021,31(28):2102770
To improve the quantum efficiency and stability of perovskite quantum dots, the structural and optical properties are optimized by varying the concentration of Ni doping in CsPbBr3 perovskite nanocrystals (PNCs). As Ni doping is gradually added, a blue shift is observed at the photoluminescence (PL) spectra. Ni-doped PNCs exhibit stronger light emission, higher quantum efficiency, and longer lifetimes than undoped PNCs. The doped divalent element acts as a defect in the perovskite structure, reducing the recombination rate of electrons and holes. A stability test is used to assess the susceptibility of the perovskite to light and moisture. For ultra-violet light irradiation, the PL intensity of undoped PNCs decreases by 70%, whereas that of Ni-doped PNCs decreases by 18%. In the water addition experiment, the PL intensity of Ni-doped PNCs is three times that of undoped PNCs. For CsPbBr3 and Ni:CsPbBr3 PNCs, a light emitting diode is fabricated by spin-coating. The efficiency of Ni:CsPbBr3 exceeds that of CsPbBr3 PNCs, and the results significantly differ based on the ratio. A maximum luminance of 833 cd m–2 is obtained at optimum efficiency (0.3 cd A–1). Therefore, Ni-doped PNCs are expected to contribute to future performance improvements in display devices. 相似文献
992.
Jinsong Wang Zhengfu Zhang Haoran Song Bao Zhang Jia Liu Xuxia Shai Ling Miao 《Advanced functional materials》2021,31(9):2008578
The reaction kinetics of alkaline hydrogen evolution reactions (HER) is a trade-off between adsorption and desorption for intermediate species (H2O, OH, and Hads). However, due to the complicated correlation between the intermediates adsorption energy and electronic states, targeted regulating the adsorption energy at the atomic level is not comprehensive. Herein, nonmetals (B, N, O, and F) are used to modulate the adsorption energy and electronic structure of Ni3S4, and propose that H2O and OH adsorption energy are correlate directly with d-band center (εd) of transition metal Ni, and Hads adsorption energy has a linear dependence on p-band center (εp) of nonmetal S. Direct experimental evidence is offered that in all nonmetals doping samples, Tafel slope and exchange current density can be improved regularly with the εd and εp, and F-Ni3S4 shows the optimum activity with tiny overpotential 29 and 92 mV for harvesting current density 10 and 100 mA cm−2, respectively. Furthermore, the micro-kinetics analysis and density functional theory calculations verify that F-doping can efficiently reduce the energy barrier of the Volmer step, eventually accelerating the HER kinetics. This work provides atomic-level insight into the structure-properties relationship, and opens an avenue for kinetic-oriented design of alkaline HER and beyond. 相似文献
993.
Avigail Landman Shabtai Hadash Gennady E. Shter Alon Ben-Azaria Hen Dotan Avner Rothschild Gideon S. Grader 《Advanced functional materials》2021,31(14):2008118
Decoupled water splitting is a promising new path for renewable hydrogen production, offering many potential advantages such as stable operation under partial-load conditions, high-pressure hydrogen production, overall system robustness, and higher safety levels. Here, the performance of electrospun core/shell nickel/nickel hydroxide anodes is demonstrated in an electrochemical-thermally activated chemical decoupled water splitting process. The high surface area of the hierarchical porous electrode structure improves the utilization efficiency, charge capacity, and current density of the redox anode while maintaining high process efficiency. The anodes reach average current densities as high as 113 mA cm−2 at a working potential of 1.48 VRHE and 64 mA cm−2 at 1.43 VRHE, with a Faradaic efficiency of nearly 100% and no H2/O2 intermixing in a membrane-free cell. 相似文献
994.
Catalysts based on earth-abundant non-noble metals are interesting candidates for alkaline water electrolysis in sustainable hydrogen economies. However, such catalysts often suffer from high overpotential and sluggish kinetics in both the hydrogen and oxygen evolution reactions (HER and OER). In this study, a hybrid catalyst made of iron-doped cobalt phosphide (Fe-CoP) nanowire arrays and Ni(OH)2 nanosheets is introduced that displays strong electronic interactions at the interface, which significantly improves the interfacial reactivity of reactants and/or intermediates with the hybrid catalyst surface. The combined experimental and theoretical study further confirms that the hybrid catalyst promotes the sluggish rate-limiting steps in both the HER and OER. Full water electrolysis is thus enabled to take place at such a low cell voltage as 1.52 V to reach the current density of 10 mA cm−2 along with superior durability and high conversion efficiency. 相似文献
995.
Hao Jiang Mingzi Sun Shuilin Wu Bolong Huang Chun-Sing Lee Wenjun Zhang 《Advanced functional materials》2021,31(43):2104951
To couple hydrogen evolution reaction (HER) with urea oxidation reaction (UOR) is a promising approach to produce H2 with reduced energy consumption. However, the development of a low-cost and high-performance bifunctional electrocatalyst toward HER and UOR is still a challenge. In this work, oxygen-incorporated nickel molybdenum phosphide nanotube arrays are synthesized on nickel foam (O-NiMoP/NF) via electrodeposition accompanied with in-situ template etching. Benefiting from the modulated electronic structure and the nanotube array architecture of O-NiMoP, the self-supporting O-NiMoP/NF electrodes demonstrate highly efficient bifunctional catalytic activity toward HER and UOR. Particularly, in the HER and UOR (HER||UOR) coupled system for H2 production, a significantly reduced cell voltage of 1.55 V is obtained at the current density of 50 mA cm–2, which is about 300 mV lower than that of the conventional water electrolysis. Density functional theory calculations reveal that the remarkable HER and UOR activities originated from the Ni sites with the modulated electronic environment induced by Mo, P and O atoms, which facilitate the water dissociation during HER and balance the adsorption/desorption of the intermediates during UOR. The development of Ni-based phosphides nanotube arrays as a bifunctional electrocatalyst in HER||OER system provides a new approach enabling energy-saving H2 production. 相似文献
996.
Muhammad Hamid Raza Kaveh Movlaee Salvatore Gianluca Leonardi Nicolae Barsan Giovanni Neri Nicola Pinna 《Advanced functional materials》2020,30(6)
Hierarchical core–shell (C–S) heterostructures composed of a NiO shell deposited onto stacked‐cup carbon nanotubes (SCCNTs) are synthesized by atomic layer deposition (ALD). A film of NiO particles (0.80–21.8 nm in thickness) is uniformly deposited onto the inner and outer walls of the SCCNTs. The electrical resistance of the samples is found to increase of many orders of magnitude with the increasing of the NiO thickness. The response of NiO–SCCNT sensors toward low concentrations of acetone and ethanol at 200 °C is studied. The sensing mechanism is based on the modulation of the hole‐accumulation region in the NiO shell layer upon chemisorption of the reducing gas molecules. The electrical conduction mechanism is further studied by the incorporation of an Al2O3 dielectric layer at NiO and SCCNT interfaces. The investigations on NiO–Al2O3–SCCNT, Al2O3–SCCNT, and NiO–SCCNT coaxial heterostructures reveal that the sensing mechanism is strictly related to the NiO shell layer. The remarkable performance of the NiO–SCCNT sensors toward acetone and ethanol benefits from the conformal coating by ALD, large surface area of the SCCNTs, and the optimized p‐NiO shell layer thickness followed by the radial modulation of the space‐charge region. 相似文献
997.
Menglei Yuan Qiongguang Li Jingxian Zhang Jiawen Wu Tongkun Zhao Zhanjun Liu Le Zhou Hongyan He Bin Li Guangjin Zhang 《Advanced functional materials》2020,30(39)
Efficient N2 fixation at ambient condition through electrochemical processes has been regarded as a promising alternative to traditional Haber–Bosch technology. Engineering surface atomic architecture of the catalysts to generate desirable active sites is important to facilitate electrochemical nitrogen reduction reaction (NRR) while suppressing the competitive hydrogen evolution reaction. Herein, nickel telluride nanocrystals with selectively exposed {001} and {010} facets are synthesized by a simple process, realizing the manipulation of surface chemistry at the atomic level. It is found that the catalysts expose the {001} facets coupled with desirable Ni sites, which possess high Faraday efficiency of 17.38 ± 0.36% and NH3 yield rate of 33.34 ± 0.70 μg h?1 mg?1 at ‐0.1 V vs RHE, outperforming other samples enclosed by {010} facets (8.56 ± 0.22%, 12.78 ± 0.43 μg h?1 mg?1). Both experimental results and computational simulations reveal that {001} facets, with selectively exposed Ni sites, guarantee the adsorption and activation of N2 and weaken the binding for *H species. Moreover, the enhanced reduction capacity and accelerated charge transfer kinetics also contribute the superior NRR performance of {001} facets. This work presents a novel strategy in designing nonprecious NRR electrocatalyst with exposed favorable active sites. 相似文献
998.
Silvia Nappini Danil W. Boukhvalov Gianluca D'Olimpio Libo Zhang Barun Ghosh Chia‐Nung Kuo Haoshan Zhu Jia Cheng Michele Nardone Luca Ottaviano Debashis Mondal Raju Edla Jun Fuji Chin Shan Lue Ivana Vobornik Jory A. Yarmoff Amit Agarwal Lin Wang Lixue Zhang Federica Bondino Antonio Politano 《Advanced functional materials》2020,30(22)
By means of theory and experiments, the application capability of nickel ditelluride (NiTe2) transition‐metal dichalcogenide in catalysis and nanoelectronics is assessed. The Te surface termination forms a TeO2 skin in an oxygen environment. In ambient atmosphere, passivation is achieved in less than 30 min with the TeO2 skin having a thickness of about 7 Å. NiTe2 shows outstanding tolerance to CO exposure and stability in water environment, with subsequent good performance in both hydrogen and oxygen evolution reactions. NiTe2‐based devices consistently demonstrate superb ambient stability over a timescale as long as one month. Specifically, NiTe2 has been implemented in a device that exhibits both superior performance and environmental stability at frequencies above 40 GHz, with possible applications as a receiver beyond the cutoff frequency of a nanotransistor. 相似文献
999.
1000.
新型催化裂化钝镍剂的研制及评价 总被引:1,自引:0,他引:1
通过单一钝镍组分之间的复配和优化获得三种新型的PN系列钝镍剂。轻油微反,重油微反和小型提升管中试放大试验研究表明,镍污染的催化剂经PN-1钝镍剂处理后能使裂化产物中氢气和焦炭产率,选择性均明显下降的同时提高裂化转化率,(液化气+汽油+柴油)收率提高了近1年百分点,改善了产品分布,显示出良好的工业应用前景。 相似文献