共查询到20条相似文献,搜索用时 15 毫秒
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Jian Li Xin Gao Zhenzhu Li Jing‐Hao Wang Lei Zhu Chen Yin Yang Wang Xu‐Bing Li Zhongfan Liu Jin Zhang Chen‐Ho Tung Li‐Zhu Wu 《Advanced functional materials》2019,29(16)
Graphdiyne (GDY), with a highly π‐conjugated structure of sp2‐ and sp‐hybridized carbon, has triggered a huge interest in water splitting. However, all of the systems perform with no consideration of the surface wettability of GDY. Herein, for the first time, the fabrication of superhydrophilic GDY electrode via air‐plasma for oxygen evolution is described. As a representative catalyst, ultrathin CoAl‐LDH (CO32?) nanosheets have been successfully assembled onto the superhydrophilic GDY electrostatically. The resulting superhydrophilic CoAl‐LDH/GDY electrode exhibites superior activity with an overpotential of ≈258 mV to reach 10 mA cm?2. The turnover frequency (TOF) is calculated to be ≈0.60 s?1 at η = 300 mV, which is the best record in both CoAl‐based and GDY‐based layered double hydroxides (LDH) electrocatalysts for oxygen evolution. Density functional theory (DFT) calculations reveal that superhydrophilic GDY has stronger interactions with catalysts and attracts H2O molecules around catalysts, thus facilitating interfacial mass/electron transportation. Further, the fabrication is capable of improving the photoelectrochemical oxygen evolution activity remarkably. The results show the great potential of superhydrophilic GDY to boost water oxidation activity by promoting interfacial mass/electron transportation. 相似文献
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Tingwen Zhao Xiangjian Shen Yuan Wang Rosalie K. Hocking Yibing Li Chengli Rong Kamran Dastafkan Zhen Su Chuan Zhao 《Advanced functional materials》2021,31(25):2100614
Nickel-based electrocatalysts are promising candidates for oxygen evolution reaction (OER) but suffer from high activation overpotentials. Herein, in situ structural reconstruction of V-doped Ni2P pre-catalyst to form highly active NiV oxyhydroxides for OER is reported, during which the partial dissolution of V creates a disordered Ni structure with an enlarged electrochemical surface area. Operando electrochemical impedance spectroscopy reveals that the synergistic interaction between the Ni hosts and the remaining V dopants can regulate the electronic structure of NiV oxyhydroxides, which leads to enhanced kinetics for the adsorption of *OH and deprotonation of *OOH intermediates. Raman spectroscopy and X-ray absorption spectroscopy further demonstrate that the increased content of active β-NiOOH phase with the disordered Ni active sites contributes to OER activity enhancement. Density functional theory calculations verify that the V dopants facilitate the generation of *O intermediates during OER, which is the rate-determining step for realizing efficient O2 evolution. Optimization of these properties endows the NiV oxyhydroxide electrode with a low overpotential of 221 mV to deliver a current density of 10 mA cm−2 and excellent stability in the alkaline electrolyte. 相似文献
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Hongyuan Yang Gonela Vijaykumar Ziliang Chen J. Niklas Hausmann Indranil Mondal Suptish Ghosh Victor C. J. Nicolaus Konstantin Laun Ingo Zebger Matthias Driess Prashanth W. Menezes 《Advanced functional materials》2023,33(41):2303702
Iron-based (pre)catalysts have attracted enormous attention for various electrooxidation reactions due to the low cost, high abundance, and multiple accessible redox states of iron. Herein, a well-defined helical iron borophosphate (LiFeBPO) is developed as an electro(pre)catalyst for the oxygen evolution reaction (OER) and selective alcohol oxidation. When deposited on nickel foam (NF), LiFeBPO exhibits an exceptional OER performance at ambient conditions attaining a current density of 100 mA cm−2 at ≈276 mV overpotential in 1 m KOH. Notably, this anode sustains durable alkaline water electrolysis at 500 mA cm−2 for over 330 h under industrial conditions (6 m KOH and 85 °C). In –situ and ex situ investigations reveal a deep reconstruction of LiFeBPO during OER, which transforms into a 3D open porous skeleton assembled by ultrasmall, low-crystalline α-FeOOH nanoparticles (interfacing with NiOOH of NF). This structure contributes to exposing accessible surface active sites, as well as accelerating mass transport and bubble detachment. Moreover, this electrode also catalyzes the electrooxidation of alcohols (methanol, ethylene glycol, and glycerol) to formic acid (FA) with high selectivity and full conversion. This study provides promising solutions for designing suitable anodes for the simultaneous production of green hydrogen fuel and value–added FA from electrooxidation reactions. 相似文献
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C与Si重构表面碰撞过程的分子动力学模拟 总被引:3,自引:0,他引:3
利用 Tersoff半经验多体相互作用势和分子动力学模拟方法研究了荷能 C原子与 Si(0 0 1) - (2× 1)重构表面碰撞动力学过程中入射 C原子能量随时间的变化情况 ,观察到了 C原子和表面 Si原子成键过程中 C原子的吸附、Si原子二聚键的打开、C原子的徙动以及 C、Si原子成键等物理过程 ,并对不同入射位置处入射 C原子和表面 Si原子碰撞过程中能量转移机理进行了分析。模拟结果表明 ,C原子相对于表面不同的局部构型发生不同的碰撞过程 ,而 C原子能量的提高有利于成键过程的发生 ,结果为 Si C在Si表面生长初期物理过程的认识提供了参考数据 相似文献
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Hai-Jun Liu Shuo Zhang Wen-Yu Yang Ning Yu Chun-Ying Liu Yong-Ming Chai Bin Dong 《Advanced functional materials》2023,33(43):2303776
Rationally constructing and manipulating the in situ formed catalytically active surface of catalysts remains a tremendous challenge for a highly efficient water electrolysis. Herein, an anion and cation co-induced strategy is presented to modulate in situ catalyst dissolution-redeposition and to achieve the directional reconstruction of Zn and S co-doped Fe2O3 and Fe3O4 on iron foams (Zn,S-Fe2O3-Fe3O4/IF), for oxygen evolution reaction (OER). Benefiting from Zn, S co-doping and the presence of Fe3O4, a directionally reconstructed surface is obtained. The Fe2O3 in the Zn,S-Fe2O3-Fe3O4/IF is directionally reconstructed into FeOOH (Zn,S-Fe3O4-FeOOH/IF), in which the S leaching promotes the Fe dissolution and the Zn co-deposition regulates the activity of the obtained FeOOH. Moreover, the presence of Fe3O4 provides a stable site for FeOOH deposition, and thus causes more FeOOH active components to be formed. Directionally reconstructed Zn,S-Fe3O4-FeOOH/IF outperformes many state-of-the-art OER catalysts and demonstrates a remarkable stability. The experimental and density functional theory (DFT) calculation results show that the introduction of Zn-doped FeOOH with abundant oxygen vacancies through directional reconstruction has activated lattice O atoms, facilitating the OER process on the heterojunction surface following the lattice oxygen mechanism (LOM) pathway. This work makes a stride in co-induced strategy modulating directional reconstruction. 相似文献
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Manoj B. Kale Rahul Anil Borse Aya Gomaa Abdelkader Mohamed Yaobing Wang 《Advanced functional materials》2021,31(25):2101313
The conventional environment polluting energy sources and the continuous growing energy demand compelled researchers to find alternative energy sources. Therefore, in recent years, extensive research has been carried out in synthesizing catalysts for energy conversion applications. This review focuses on the application of various electrodeposition methods in the synthesis of energy-related electrocatalyst and briefly discusses different electrocatalyst characterization techniques. Further, the influence of various parameters on the electrocatalyst activity and stability is highlighted. Electrocatalyst application in clean energy conversion reactions, such as the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, nitrogen reduction reaction along with the metal-air/CO2 battery, are reviewed. Finally, the comparative experimental data are provided as a reference to synthesize the next-generation electrodeposited electrocatalyst in clean energy conversions and beyond. 相似文献
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Photoinduced Absorption Spectroscopy of CoPi on BiVO4: The Function of CoPi during Water Oxidation 下载免费PDF全文
Yimeng Ma Andreas Kafizas Stephanie R. Pendlebury Florian Le Formal James R. Durrant 《Advanced functional materials》2016,26(27):4951-4960
This paper employs photoinduced absorption and electrochemical techniques to analyze the charge carrier dynamics that drive photoelectrochemical water oxidation on bismuth vanadate (BiVO4), both with and without cobalt phosphate (CoPi) co‐catalyst. These results are correlated with spectroelectrochemical measurements of CoII oxidation to CoIII in a CoPi/FTO (fluorine doped tin oxide) electrode during dark electrocatalytic water oxidation. Electrocatalytic water oxidation exhibits a non‐linear dependence on CoIII density, with a sharp onset at 1 × 1017 CoIII cm?2. These results are compared quantitatively with the degree of CoPi oxidation observed under conditions of photoinduced water oxidation on CoPi–BiVO4 photoanodes. For the CoPi–BiVO4 photoanodes studied herein, ≤5% of water oxidation proceeds from CoPi sites, making the BiVO4 surface the predominant water oxidation site. This study highlights two key factors that limit the ability of CoPi to improve the catalytic performance of BiVO4: 1) the kinetics of hole transfer from the BiVO4 to the CoPi layer are too slow to effectively compete with direct water oxidation from BiVO4; 2) the slow water oxidation kinetics of CoPi result in a large accumulation of CoIII states, causing an increase in recombination. Addressing these factors will be essential for improving the performance of CoPi on photoanodes for solar‐driven water oxidation. 相似文献
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铝衰减膜表面氧化对软X光透过率的影响与修正 总被引:1,自引:0,他引:1
对用不同方法制备的软X光激光实验用的Al衰减膜样品,用Auger电子能谱(AES)结合氩离子束刻蚀进行了组分的表面和深度分布分析,结果表明表面氧化层主要由Al2O3组成,氧化达到饱和时的氧化层厚度≈7.5nm。由于在软X光波段内,氧的吸收系数比铝大一个多数量级,这一氧化层对软X光透过率的影响甚大。将AES测试结果作为参数,使用公式I=I0·exp[-μ(E)·(ρd)]对X光透过强度进行修正。同步辐射软X光对样品透过率的直接测量表明,对于透过率大于20%的Al膜,直接测量结果与按修正公式计算的结果在最大偏差11%范围内符合。 相似文献
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Guowei Li Qun Yang Jiancun Rao Chenguang Fu Sz‐Chian Liou Gudrun Auffermann Yan Sun Claudia Felser 《Advanced functional materials》2020,30(12)
Carbon‐based materials have been widely used in heterogeneous catalysis because of their advantages of high surface area, thermal stability, and chemical inertness. However, their role in the catalysis is not fully understood although most studies conclude that the coupling between the carbon support and catalyst could reduce the charge transfer resistance and improve the kinetics of catalytic reactions such as water splitting. In this study, a carbon‐modified FeP2 electrocatalyst with a one‐step strategy is synthesized. The tensile strain is introduced in situ in the ab crystal plane of the FeP2 catalyst. This leads to charge redistribution between H and O atoms in the OH bonds and enhances the adsorption of reaction intermediates. In the water oxidation process, this results in a decrease in the energy barrier for the rate‐determining step, specifically, the chemical step of *OH adsorption preceded by one‐electron transfer. Benefiting from the optimized adsorption energy, the strained catalysts exhibit excellent oxygen evolution reaction (OER) activity with a low overpotential in addition to their increased stability. This study provides a new strategy for the introducing of strains in functional materials and provides new insights into the influence of carbon modification on OER activity. 相似文献
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GaAs纳米线通常呈现纤锌矿结构(WZ),而WZ(1010)侧面已被实验所观测到。利用第一性原理计算了GaAs(1010)的表面弛豫和表面能,计算结果表明:(1010)A表面只出现原子的弛豫现象,表面能为40.6×1020meV/m2;而(1010)B表面却重构形成了GaGa和AsAs二聚体,表面能为63.5×1020meV/m2。相对于ZB(110)表面,WZ(1010)A面具有更低的表面能,(1010)A表面具有更好的稳定性,说明了在表面能占重要影响的纳米线中WZ结构存在的合理性。 相似文献
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The development of bifunctional electrocatalysts for overall water splitting in acidic media is vital for polymer electrolyte membrane (PEM) electrolyzers, but still full of obstacles. Here, highly efficient acidic overall water splitting is realized by utilizing ultrasmall, monodispersed Iridium (Ir)‐based nanoclusters (NCs) as the candidate, via a surfactant‐free, wet‐chemical, and large‐scalable strategy. Benefiting from the high specific surface area, clean surface, and strong binding between NCs and supports, the IrM NCs exhibit attractive activities and durability for both oxygen evolution reaction and hydrogen evolution reaction in acidic electrolytes, with IrNi NCs showing the best performance. More significantly, in the overall water splitting, IrNi NCs reach 10 mA cm?2 at a cell voltage of only 1.58 V in 0.5 m H2SO4 electrolyte, holding promises for potential implementation of PEM water electrolysis. This work opens a new avenue toward designing bifunctional “acidic stable” catalysts for efficient overall water splitting. 相似文献
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Anatase (101) Reconstructed Surface with Novel Functionalities: Desired Bandgap for Visible Light Absorption and High Chemical Reactivity 下载免费PDF全文
Rulong Zhou Bingyan Qu Dongdong Li Xiaorui Sun Xiao Cheng Zeng 《Advanced functional materials》2018,28(8)
Unreconstructed surfaces of anatase TiO2 are known to have two main limitations for their application as photocatalysts, namely, low efficiency for sun‐light absorption due to the wide bandgap, and low chemical reactivity. Strategies to overcoming the two limitations and to enhancing TiO2's photocatalytic efficiency have been highly sought. To this end, a global search of anatase reconstructed surfaces is performed based on the evolutionary method. It is found that the newly predicted anatase (101) reconstructed surface possesses a desired bandgap whose value is within the energy domain of visible light as well as notably high chemical reactivity compared to the unreconstructed anatase (101) surface. In particular, it is predicted that under Ti‐richness condition, the anatase (101) reconstructed surface is energetically very stable. The anatase (101) reconstructed surface exhibits similar topmost surface structure as the unreconstructed anatase (101) surface but different subsurface structure. Not only the fivefold coordinated Ti atoms (Ti5c) in the topmost surface layer but also the sixfold coordinated Ti atoms in the subsurface layer contribute to the desirable gap states. The high chemical reactivity of anatase (101) reconstructed surface can be attributed to the extra electrons drawn by the surface Ti5c atoms and subsurface Ti6c atoms. 相似文献
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Michael Beetz Sebastian Häringer Patrick Elsässer Jonathan Kampmann Lena Sauerland Florian Wolf Marcella Günther Anna Fischer Thomas Bein 《Advanced functional materials》2021,31(45):2011210
As global warming caused by the greenhouse effect is becoming one of the major issues of the 21st century, hydrogen as an alternative to fossil-based fuels and other energy carriers has gained importance in current research. One promising approach to produce hydrogen is photoelectrochemical water splitting, which uses solar energy combined with suitable semiconducting photoabsorber electrodes to generate hydrogen and oxygen from water. However, most water splitting applications reported to date suffer from degradation of the photoabsorber, resulting in a loss of activity after just a few seconds or minutes. Here, a new approach using conformal ultra-thin and oxidation-stable protective layers is presented on Mo:BiVO4 thin films combined with a thin Fe0.1Ni0.9O water oxidation co-catalyst, applied by electrochemical deposition, to achieve unprecedented photocurrent densities of up to 5.6 mA cm−2 under simulated AM1.5G illumination and a neutral pH while providing more stable electrodes for water oxidation. 相似文献
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单晶硅表面载流子动力学的超快抽运探测 总被引:2,自引:0,他引:2
利用800 nm波长的飞秒抽运探测技术测量了单晶硅表面50 ps内的瞬态反射率变化,研究了表面载流子的超快动力学过程.基于自由载流子密度变化过程建立的反射率模型可以很好地描述瞬态反射率变化,说明受激自由载流子超快响应的贡献主导了反射率的变化过程.经拟合获得了样品的表面复合速度(SRV)为1.2×106cm/s.建立了耦合的载流子输运模型,探讨了单晶硅表面热载流子的密度、温度随时间的演化过程.研究表明,表面复合过程是影响本征单晶硅表面载流子动力学的重要因素. 相似文献
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Yuanting Dong Qintao Sun Changhong Zhan Juntao Zhang Hao Yang Tao Cheng Yong Xu Zhiwei Hu Chih-Wen Pao Hongbo Geng Xiaoqing Huang 《Advanced functional materials》2023,33(5):2210328
Ru has recently been considered as a promising alternative of Pt toward hydrogen oxidation reaction (HOR) due to its lower price and similar hydrogen binding energy (HBE) in comparison to Pt. Nevertheless, the catalytic performance of Ru toward HOR is far from the satisfaction of practical application. Herein, it is demonstrated that the modification of Ru multi-layered nanosheet (MLNS) with Ni can significantly promote the HOR performance. In particular, the HOR performance is strongly related to the Ni location on the surface or in the lattice of Ru MLNS. Experimental and theoretical investigations suggest that Ni in the lattice of Ru MLNS (lattice engineering) optimizes the HBE, while Ni species on the surface (surface engineering) decrease the free energy of water formation, as a result of the significantly enhanced HOR performance. The optimal catalyst, where Ni is located both on the surface and in the lattice, displays superior alkaline HOR performance to commercial Pt/C and Ru/C. The present study not only systematically reveals the significance of Ni modification on Ru toward HOR, but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond. 相似文献