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91.
Yingying Xing Di Li Longhua Li Huamei Tong Deli Jiang Weidong Shi 《International Journal of Hydrogen Energy》2021,46(11):7989-8001
Electrocatalytic hydrogen evolution under alkaline media holds great promising in hydrogen energy production. Transition-metal sulfides (TMSs) are attractive for electrocatalytic alkaline hydrogen evolution, yet their catalytic performance is unsatisfactory owing to the sluggish water dissociation kinetics. Herein, a Mn/N co-doping strategy is proposed to regulate the water dissociation kinetics of Co9S8 nanowires array grown on nickel foam thus improve the activity of hydrogen evolution reaction (HER). The optimal Mn/N co-doping Co9S8 (Mn–N–Co9S8) catalyst achieves low overpotentials of 102 and 238 mV at 10 and 100 mA cm?2 in the 1 M KOH solution, respectively, remarkably higher than the single-doping Mn–Co9S8 and N–Co9S8 as well as superior to many reported Co9S8-based HER electrocatalysts. Density functional theory (DFT) calculation results confirm that the water dissociation barrier of the Mn–N–Co9S8 is reduced significantly owing to the synergistic co-doping of Mn and N, which accounts for the enhanced alkaline HER performance. This study offers an effective strategy to enhance the alkaline HER activity of TMSs by accelerating water dissociation kinetic via the cation and anion co-doping strategy. 相似文献
92.
Xiaobing Yang Weisen Yang Xingping Fu Jiapeng Hu Juan Chen 《International Journal of Hydrogen Energy》2021,46(35):18318-18325
Splitting water for hydrogen production is still a promising technique to meet the energy requirements of society and overcome many environmental problems. However, the development of carbon-based transition electrocatalysts with superior activity for hydrogen evolution reaction (HER) is still challenging. In this study, a CoNiMo/NPC electrocatalyst was successfully fabricated using ZIF-67 as a precursor via facile absorption, pyrolysis and annealing processes. The fabricated CoNiMo/NPC was used as an electrocatalyst for hydrogen production. The results revealed that the doping of Ni and Mo increase the number of active sites and enhance the conductivity of electrocatalysts. CoNiMo/NPC exhibits excellent HER activity in alkaline solutions and only requires an overpotential of 182 mV to reach a current density of 10 mA/cm2. Furthermore, long-term measurements demonstrated that CoNiMo/NPC has superior durability in alkaline solutions. The excellent HER performance of CoNiMo/NPC can be attributed to the doping of Co, Ni, and Mo on porous carbon. In addition, the high specific surface area and high graphitisation degree of the electrocatalyst are beneficial for rapid charge transport and collection. 相似文献
93.
Yanyan Wu Zijuan Xie Ying Li Zhe Lv Lingling Xu Bo Wei 《International Journal of Hydrogen Energy》2021,46(49):25070-25080
Developing efficient oxygen evolution reaction (OER) electrocatalysts with earth-abundant elements is very important for sustainable H2 generation via electrochemical water splitting. Here we design a crystalline-amorphous Ni–Fe–Al hybrid phosphides nanosheet arrays grown on NiFe foam for efficient OER application. Dynamic surface reorganization of phosphides at anodic/cathodic polarizations is probed by in situ Raman spectroscopy. The reconstructed amorphous Ni(Fe)OOH species are determined as the active phases that facilitate the OER process. This unique electrode shows highly catalytic activity toward water oxidation, achieving the current densities of 10 and 100 mA cm?2 at 181 and 214 mV in 1 M KOH, respectively. Meanwhile, it also exhibits excellent stability at a large current density of 100 mA cm?2 for over 60 h. This work reveals the dynamic structural transformation of pre-catalyst in realistic conditions and highlights the important role of oxyhydroxides as real reactive species in OER process with high activity. 相似文献
94.
《International Journal of Hydrogen Energy》2021,46(55):28110-28120
In the recent past, layered zinc-based vanadium spinel oxides (ZnVOs) have shown an intriguing way to accomplish the challenges of energy conversion, storage, and utilization issues. Here, through first-principles calculations, a comprehensive study has been carried out to investigate the AV2M (where A = Zn, Zn2, Zn3, Zn4, and M = O4, O6, O7, O8, O9 respectively) electronic, photocatalytic, and optical properties. Formation energies with a negative sign express that the final compounds from the pure elements are possible and cohesive energies revealed that compounds are energetically stable. Spin-polarized calculations are also taken into account for better approximation of the electronic properties (band structure and density of states). All layered structures show indirect bandgap for spin-up calculations in range 0.3 eV–2.4 eV, while spin-down calculations show mix trends in range 2.3 eV–3.50 eV. An appropriate band edge with large enough kinetic over-potentials of the oxygen evolution reaction (ΔEV ≥ 1.244 eV) makes them potential candidates as photoanode for water splitting. ZnV2O4 is more suitable for OER as it has small kinetic overpotential as compared to the oxidation potential of water. Interestingly, all ZnVOs display a dramatically large coefficient (~105 cm−1) for optical absorption. Photogenerated electrons and holes on the layered zinc-based vanadium spinel oxide surfaces could make these spinel oxides promising materials for photocatalytic water splitting and solar energy conversion. 相似文献
95.
《International Journal of Hydrogen Energy》2021,46(76):37746-37756
Rational design of oxygen evolution reaction (OER) electrocatalysts with advance nanostructures and composition superiority is an urgent need to promote electrocatalytic property. In this research, we fabricate Fe–NiCoP/NiCoP/NF electrocatalyst for OER via the interfacial scaffolding strategy with Prussian-blue-analogue (PBA) followed by low-temperature phosphating. The cube-on-sheet multimetallic-TMPs-based nanoarchitecture of Fe–NiCoP/NiCoP/NF exhibits outstanding OER performance, which only requires the overpotential of 201 mV to achieve a current density of 10 mA cm−2 and possesses good durability up to 50 h in 1.0 M KOH solution. The superior OER property of Fe–NiCoP/NiCoP/NF is mainly characteristic to the rich composition that optimizes the electronic structure and the cube-on-sheet multimetallic-TMPs-based nanoarchitecture which can facilitate more effective active sites exposure and ultimately promote charge transfer at the same time. This research provides a new strategy for the construction of advanced nanoarrays structure and the improvement of the electrocatalytic performance of polymetallic phosphides, which offers its promising applications especially in energy storage and conversion technology. 相似文献
96.
Sruthi Guru Shubham Kumar Sankeerthana Bellamkonda Ranga Rao Gangavarapu 《International Journal of Hydrogen Energy》2021,46(30):16414-16430
A nanocomposite CuTi layered double hydroxide (LDH) supported on g-C3N4 (15 wt% of g-C3N4) is facilely synthesized by hydrothermal method. There are electrostatic interactions between positive layers of CuTi-LDH and negatively charged inner g-C3N4 sheets. The nanocomposite and its precursors are characterized through various analytical techniques, which affirmed the presence of both g-C3N4 and CuTi-LDH characteristic features. The pore-enriched hybrid geometry of CuTi-LDH@g-C3N4 with high specific surface area (146 m2/g), and suitable band gap of 2.46 eV enables the nanocomposite to act as both an electrocatalyst and photoelectrocatalyst for oxygen evolution reaction (OER). Both the electrochemical and photoelectrochemical studies are done using 1 M KOH (pH = 13.6) with applied potential of ?0.2 V to 1.5 V vs. Ag/AgCl. The onset potential of CuTi-LDH@g-C3N4 for OER appears at η = 0.36 V in dark and η = 0.32 V under visible light illumination of 30 min. Also, Mott-Schottky analysis shows n-type semiconductor behaviour for CuTi-LDH@g-C3N4 and its precursors. The photoelectrochemical water oxidation proceeds by charge transfer across a Type II heterojunction formed between the CuTi-LDH and g-C3N4 materials. 相似文献
97.
Gang Liu Jingjing Li Chao Dong Liyuan Wu Dan Liang Huawei Cao Pengfei Lu 《International Journal of Hydrogen Energy》2021,46(35):18294-18304
Searching for the catalysts with excellent catalytic activity and high chemical stability is the key to achieve large-scale production of hydrogen (H2) through hydrogen evolution reaction (HER). Two-dimensional (2D) platinum and palladium dichalcogenides with extraordinary electrical properties have emerged as the potential candidate for HER catalysts. Here, chemical stability, HER electrocatalytic activity, and the origin of improved HER performance of Pt/Pd-based dichalcogenides with single-atom doping (B, C, N, P, Au, Ag, Cu, Co, Fe, Ni, Zn) and vacancies are explored by first-principles calculations. The calculated defect formation energy reveals that most defective structures are thermodynamically stable. Hydrogen evolution performance on basal plane is obviously improved by single-atoms doping and vacancies. Particularly, Zn-doped and Te vacancy PtTe2 have a ΔGH value close to zero. Moreover, defect engineering displays a different performance on HER catalytic activity in sulfur group elements, in order of S < Te < Se in Pd-based chalcogenides, and S < Se < Te in Pt-based chalcogenides. The origin of improved hydrogen evolution performance is revealed by electronic structure and charge transfer. Our findings of the highly activating defective systems provide a theoretical basis for HER applications of platinum and palladium dichalcogenides. 相似文献
98.
《International Journal of Hydrogen Energy》2021,46(68):33679-33688
Besides developing a large number of catalysts for hydrogen evolution reaction (HER) in alkaline electrolytes, its conversion efficiency remained low. Herein, we have developed mixed-dimensional heterostructures of niobium disulfide (NbS2) with graphene foam grown on nickel foam (NbS2-Gr-NF). The strong lateral fusion results in activating the catalytic sites of NbS2, the three-dimensional substrate provides easy access of electrolyte to active sites and increased electrochemically active surface area, while enhanced conductivity provides faster transfer of electrons to and from active sites. Therefore, NbS2-Gr-NF heterostructures resulted in an exceptionally high current density of 500 mA cm−2 at a very low overpotential of 306 mV in 1 M KOH solution and even can achieve the current density values of 914 mAcm−2 at 338 mV only at a slight increase in overpotential (32 mV). Moreover, a Tafel value of ~72 mV dec−1 confirms that as-developed heterostructure provides fast reaction kinetics where the reaction is mainly controlled by the Volmer step. Achieving such high current density at a faster rate with high stability makes NbS2-Gr-NF heterostructures a potential candidate for water-splitting, especially in alkaline electrolytes. 相似文献
99.
Selvasundarasekar Sam Sankar Arumugam Rathishkumar Kathiresan Geetha Subrata Kundu 《International Journal of Hydrogen Energy》2021,46(17):10366-10376
Electrospinning (ES) is a most reliable method for synthesizing one dimensional (1D) fibrous material. Fibrous materials are having peculiar interest owing to their fascinating properties. For efficient hydrogen fuel generation, electrocatalytic water splitting is one of the finest way of producing hydrogen in a pure form. But it is encountered by the counter oxygen evolution reaction (OER) in more often. As of now, noble metal based catalysts are utilized in the commercial sector. Some of the disadvantages associated with the noble materials are restrict their usage commercially. To address this issue, herein, we have synthesized One dimensional (1D), hydrated porous cobalt phosphate fibrous network by an ES method and act as an electrocatalyst for OER in both alkaline and neutral media for the first time, which exhibits an overpotential of 245 and 457 mV respectively at a current density of 10 mAcm?2 with astonishing stability. 相似文献
100.
《International Journal of Hydrogen Energy》2021,46(79):39438-39456
This study demonstrates the structural properties and evaluates the electrocatalytic activity of an ethanol oxidation reaction using ternary materials composed by Pd and Sn nanoparticles combined with CeO2 nanorods (NR) anchored on Vulcan carbon black to be used as an anode in alkaline direct ethanol fuel cells (ADEFCs). The highest open circuit voltage (1010 mV), maximum power (30 mW cm−2) and current densities (113 mA cm−2) were achieved using (Pd1Sn3)10(CeO2 NR)20(Vn)70, while the commercial anode values were 968 mV, 23 mW cm−2 and 123 mA cm−2. Although similar performance for both anodes was observed, the ternary hybrid electrocatalyst contains an 8-fold lower Pd content than the commercial material. This outcome may be justified by the higher defect density presented by the carbon support observed by Raman spectroscopy and the metal oxidation state modifications detected by X-ray photoelectron spectroscopy, as well as the electrochemically active surface area presented by the ternary electrocatalyst. The combination of higher vacancies, defects and oxygenated species in the carbon support and the synergistic effect between the oxyphilic Sn and CeO2 NR species and the Pd nanoparticles results in an electrochemical performance that makes these ternary electrocatalysts promising anode materials for ADEFC applications. 相似文献