共查询到20条相似文献,搜索用时 11 毫秒
1.
Dandan Wei Wujian Tang Yinling Wang 《International Journal of Hydrogen Energy》2021,46(40):20950-20960
The urea solution electrolysis has become more attractive than water splitting, because it not only produces clean H2 via the cathodic hydrogen evolution reaction (HER) with lower cell voltage, but also treats sewage containing urea through anodic urea oxidation reaction (UOR). However, lack of efficient electrocatalysts for HER and UOR has limited its development. Herein, hairy sphere -like Ni9S8/CuS/Cu2O composites were synthesized on nickel foam (NF) in situ by a two-step hydrothermal method. The Ni9S8/CuS/Cu2O/NF exhibited good electrocatalytic activity for both HER (?0.146 V vs. RHE to achieve 10 mA cm?2) and UOR (1.357 V vs. RHE to achieve 10 mA cm?2). Based on the bifunctional properties of Ni9S8/CuS/Cu2O/NF, a dual-electrode urea solution electrolytic cell was constructed, which only needed a low voltage of 1.47 V to reach a current density of 10 mA cm?2, and displayed a good stability during a 20-h test. In addition, the reason for the good catalytic activity of Ni9S8/CuS/Cu2O/NF was analyzed and the UOR mechanism was discussed in detail. Our research shows that Ni9S8/CuS/Cu2O/NF is a very promising low-cost dual-function electrocatalyst, which can be used for high-efficiency electrolysis of urea solution to produce hydrogen and treat wastewater. 相似文献
2.
《International Journal of Hydrogen Energy》2020,45(1):23-35
In targeting the most important energy and environmental issues in current society, the development of low-cost, bifunctional electrocatalysts for urea-assisted electrocatalytic hydrogen (H2) production is an urgent and challenging task. In this work, interlaced rosette-like MoS2/Ni3S2/NiFe-layered double hydroxide/nickel foam (LDH/NF) is successfully synthesized by a two-step hydrothermal reaction. Due to its unique interlaced heterostructure, MoS2/Ni3S2/NiFe-LDH/NF exhibits excellent bifunctional catalytic activity towards the urea oxidation reaction (UOR) and the hydrogen evolution reaction (HER) in 1.0 M KOH with 0.5 M urea. In a concurrent two-electrode electrolyser (MoS2/Ni3S2/NiFe-LDH/NF(+,-)), only voltage of 1.343 V is required to reach 50 mA cm−2, which is 216 mV lower than for pure water splitting. Furthermore, after 16 h of urea electrolysis in 1.0 M KOH with 0.5 M urea, the current density remains at 98% of the original value. Thus, the catalyst is not only favorable for H2 production, but also has great significance for the problem of urea-rich wastewater treatment. 相似文献
3.
Zhaoxia Yang Yanqing Zhang Chuanqi Feng Huimin Wu Yu Ding He Mei 《International Journal of Hydrogen Energy》2021,46(50):25321-25331
Water electrolysis is one of the important methods for hydrogen production, but the oxygen evolution reaction (OER) on the anode has a higher theoretical potential. Using urea oxidation reaction (UOR) instead of OER has been an energy-saving method because it has a lower theoretical potential and also can reduce pollution. In this paper, NiCoZn LDH/NF, P–NiCoZn LDH/NF-X (X is the atom ratio of P) = 10%, 15%, 20%) were synthesized through typically hydrothermal and calcination methods. P–NiCoZn LDH/NF-15% was demonstrated to be abifunctional electrocatalyst towards HER and UOR. When P–NiCoZn LDH/NF-15% is used as the anode and cathode for urea-water electrolysis,it shows that when the current density is 100 mA cm?2, the voltage is 1.479 V for urea-water electrolysis, which is much better than that of IrO2/NF||Pt/C/NF (1.698 V). Thus, P–NiCoZn LDH/NF-15% is expected to replace precious metals for practical applications. 相似文献
4.
《International Journal of Hydrogen Energy》2020,45(28):14199-14207
Finding a suitable replacement for the high potential of anodic water electrolysis (oxygen evolution reaction (OER)) is significant for hydrogen energy storage and conversion. In this work, a simple and scalable method synthesizes a structurally unique Ni3N nanoarray on Ni foam, Ni3N-350/NF, that provides efficient electrocatalysis for the urea oxidation reaction (UOR) that transports 10 mA cm−2 at a low potential of 1.34 V. In addition, Ni3N-350/NF exhibits electro-defense electrocatalytic performance for hydrogen evolution reaction, which provides a low overpotential of 128 mV at 10 mA cm−2. As proof of concept, all-water-urea electrolysis measurement is carried out in 1 M KOH with 0.5 M Urea with Ni3N-350/NF as cathode and anode respectively. Ni3N-350/NF||Ni3N-350/NF electrode can provide 100 mA cm−2 at a voltage of only 1.51 V, 160 mV less than that of water electrolysis, which proves its commercial viability in energy-saving hydrogen production. 相似文献
5.
《International Journal of Hydrogen Energy》2020,45(29):14660-14668
It is crucial for the storage and conversion of hydrogen energy to substitute the low theoretical potential of urea oxidation reaction (UOR) for the high theoretical potential of anodic water electrolysis (oxygen evolution reaction (OER)). In this paper, it puts forward a brief and scalable strategy, so as to synthesize a novel bifunctional nickel-iron layered double hydroxide and multi-walled carbon nanotube composites supported on Ni foam, represented as NiFe-LDH/MWCNTs/NF. Electrochemical measurements demonstrate that NiFe-LDH/MWCNTs/NF is able to realize an efficient electrocatalysis for UOR. During this process, merely a potential of 1.335 V is needed at 10 mA cm−2, which can be taken to replace OER, thus reducing overpotential in H2-production as well as power consumption. In addition, NiFe-LDH/MWCNTs/NF also exhibits electro-defense electrocatalytic efficiency to achieve the reaction of hydrogen evolving process, which provides a low overpotential of 98 mV at 10 mA cm−2. To further prove it, all-water-urea electrolysis measurement is carried out in 1 M KOH and 0.5 M Urea with NiFe-LDH/MWCNTs/NF as cathode and anode respectively. NiFe-LDH/MWCNTs/NF||NiFe-LDH/MWCNTs/NF electrode manages to provide 10 mA cm−2 at a voltage of merely 1.507 V, 156 mV lower than that of water splitting, which proves its commercial viability in energy-saving hydrogen production. 相似文献
6.
《International Journal of Hydrogen Energy》2022,47(83):35203-35214
Water electrolysis for producing hydrogen is considered to be the most feasible means to develop new green energy. Compared with above, urea electrolysis can improve energy conversion efficiency by introducing urea, and can also be used for purification of wastewater rich in urea. In this paper, a bifunctional electrocatalyst with heterostructure, namely Fe7Se8@Fe2O3 nanosheets supported on nickel foam, were synthesized for the first time through typical hydrothermal and partial oxidation processes. Iron cation promotes electron transfer and adjusts electron structure under the synergistic action of selenium and oxygen anion, thus achieving excellent catalytic activity of urea electrolysis. In an alkaline solution of 1 M KOH with 0.5 M urea, the Fe7Se8@Fe2O3/NF catalyst can drive the current density of 10 mA cm?2 with requiring only potential of 1.313 V and overpotential of 141 mV for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER), respectively. What is noteworthy is that Fe7Se8@Fe2O3/NF heterostructure is used as bifunctional electrocatalyst to form urea electrolyzer device, which only needs potential of 1.55 V to drive current density of 10 mA cm?2, which is one of the best catalytic activities reported so far, and the electrode couple showed remarkable stability for 15 h. Density functional theory shows that the Fe7Se8@Fe2O3/NF material exhibits the minimum Gibbs free energy for the adsorption of hydrogen. This work provides a new method for exploring novel and environmentally friendly bifunctional electrocatalysts for urea electrolysis. 相似文献
7.
《International Journal of Hydrogen Energy》2020,45(15):8433-8443
Development of highly effective and stable electrocatalysts is urgent for various energy conversion applications. Herein, a facile co-reduction approach was developed to fabricate three-dimensional (3D) hyperbranched PtRh nanoassemblies (NAs) under solvothermal conditions, where creatinine and cetyltrimethylammonium chloride (CTAC) were employed as the structure-directing agents. The as-synthesized nanocatalyst exhibited intriguing catalytic characters for hydrogen evolution reduction (HER) with a low overpotential (20 mV) at 10 mA cm−2 and a small Tafel slope (49.01 mV dec−1). Meanwhile, the catalyst showed remarkably enlarged mass activity (MA: 2.16/2.02 A mg−1) and specific activity (SA: 4.16/3.88 mA cm−2) towards ethylene glycol and glycerol oxidation reactions (EGOR and GOR) alternative to commercial Pt black and homemade Pt3Rh nanodendrites (NDs), PtRh3 NDs and Pt nanoparticles (NPs). This method offers a feasible platform to fabricate bifunctional, efficient, durable and cost-effective nanocatalysts with finely engineered structures and morphologies for renewable energy devices. 相似文献
8.
《International Journal of Hydrogen Energy》2022,47(22):11447-11455
Replacing dynamics-restricted oxygen evolution reaction (OER) with smart urea oxidation reaction (UOR) is very important for reducing the power consumption for hydrogen production. Here, the Co3Mo3N-400/NF is prepared using a facial way, which exhibits remarkable catalytic performances for UOR, hydrogen evolution reaction (HER) and overall urea electrolysis (OUE) because of the more exposed active sites and high electrical conductivity. At 100 mA/cm2, the Co3Mo3N-400/NF shows a small potential of 1.356 V vs. RHE (reversible hydrogen electrode) for UOR, which is much lower than that for OER. Furthermore, for HER, to reach to 100 mA/cm2, a low overpotential of 299 mV is required, and the urea has negligible influence on the HER process. For OUE, the Co3Mo3N-400/NF||Co3Mo3N-400/NF shows a small cell potential of 1.481 V at 100 mA/cm2 along with a good durability. Our work provides more choice for future OUE to generate hydrogen. 相似文献
9.
《International Journal of Hydrogen Energy》2023,48(21):7655-7669
Developing highly efficient bifunctional urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) catalysts for urea splitting to hydrogen are one of the strategies to cope with the energy crisis. Here, a series of CrxPy-a/ComPn-b composites were synthesized on Ni foam through hydrothermal and low-temperature phosphorization process for the first time. It is worth noting that CrxPy-1/ComPn-3@NF exhibited excellent UOR performance (1.331 V at 100 mA cm?2) and HER performance (0.299 V at 100 mA cm?2) in an electrolyte of 1 M KOH and 0.5 M urea due to the synergistic effect of Cr–Co. The CrxPy-1/ComPn-3@NF||CrxPy-1/ComPn-3@NF two-electrode system call for only 1.52 V to provide current density of 10 mA cm?2, which is one of the best electrochemistry performances reported up to now. Experimental analysis show that the promoted electrochemistry performances is assigned to faster charge transfer rate, the exposure of more reaction site and better properties of metals. Density Functional theory (DFT) results demonstrate that the presence of the ComPn material accelerates the kinetics of hydrogen production and the CrxPy material improves the properties of metals for the electrode. The work provides a new idea to develop the environmentally friendly and low cost overall urea splitting catalyst with transition metals instead of noble metals. 相似文献
10.
《International Journal of Hydrogen Energy》2022,47(25):12539-12546
The development of high-performance, low cost and earth abundant catalysts for hydrogen evolution reaction (HER) is desired. This work presents amorphous CoFeB supported on nickel foam (NF), prepared by a facial chemical reduction method, as an active catalyst for HER in alkaline solution. Structure characterization indicated that with the incorporation of Fe atom, CoFeB catalysts exhibit similar petal-like granular morphology as CoB. The optimal CoFeB/NF-0.15 catalyst exhibits Brunauer-Emmett-Teller (BET) surface area of 27.4 m2 g?1, nearly two times larger than 13.2 m2 g?1 for CoB, suggesting higher specific surface area. CoFeB/NF-0.15 catalyst shows excellent HER performance and reaches ?10 mA cm?2 at overpotential of 35 mV in alkaline solution, and Tafel slope of 84.7 mV dec?1, indicative of Volmer-Heyrovsky reaction mechanism. The synergistic effect among Fe, Co and B atoms and the more exposed active sites as well as faster electron transfer kinetics collectively contributed to the improved intrinsic activity of CoFeB for HER. Moreover, CoFeB/NF-0.15 exhibits good stability for over 16 h. 相似文献
11.
《International Journal of Hydrogen Energy》2022,47(10):6620-6630
It is very important to develop hydrogen evolution catalyst with high activity and low cost to solve energy crisis. The abundant non-precious metals and phosphides have attracted much attention and are expected to replace platinum catalysts. Herein, we report an approach to prepare nest-like porous MnCo–P electrocatalyst on the nickel foam by two-step electrodeposition. The prepared bimetallic phosphide MnCo–P3/NF has excellent hydrogen catalytic activity. In the 1 M NaOH solution, the current density of 10 mA cm?2 required overpotential is only 47 mV, its Tafel slope is 56.4 mV dec?1, and the higher current density 100 mA cm?2 required overpotential is only 112 mV. More importantly, the MnCo–P3/NF catalyst has a long-term stability of electrocatalytic hydrogen evolution. After 24 h catalytic hydrogen evolution test at a constant current density of 20 mA cm?2, its potential basically does not change. Furthermore, the current density only changes slightly after 1500 cycles of CV test. All these well prove that the prepared MnCo–P3/NF catalyst has a long-term hydrogen evolution stability. According to performance testing and morphological characterization, the MnCo–P3/NF has a high hydrogen catalytic activity and stability are due to its larger active area, lower interface charge transfer resistance and stronger mechanical stability. In summary, the study explores a method of preparing bimetallic phosphides as an efficient and stable hydrogen evolution catalyst. 相似文献
12.
Pd modified Pt over a novel support of tungsten carbide nanocrystals (the catalyst denotes as PtPd-WC/C) have been prepared by using an intermittent microwave heating (IMH) method. The as-prepared electrocatalysts are characterized by using the techniques of XRD, SEM, TEM, linear sweeping voltammetry and tested for the hydrogen evolution reaction (HER) in the acidic media. It shows a better performance for the HER on PtPd-WC/C electrocatalyst than that on Pt-WC/C electrocatalyst. In addition, these effects on the catalytic activity by changing environmental temperature and electrolyte concentration were taken into account. Kinetic study shows that the HER on the PtPd-WC/C electrocatalyst gives higher exchange current density in H2SO4 solution with high concentration, leading to a lower overpotential and facile kinetics. XRD, SEM and TEM images of PtPd-WC/C show the crystalline features of Pt, Pd and tungsten carbides and indicated the coexistence of these components. 相似文献
13.
《International Journal of Hydrogen Energy》2019,44(45):24712-24718
Developing efficient, non-noble electrocatalysts for hydrogen evolution reaction (HER) is of high significance for future energy supplement, but challenging. NiMo alloy is a non-noble-metal-based efficient catalyst for HER due to its appropriate hydrogen binding energy and excellent alkali corrosion resistance. Herein, for the first time, we report the preparation of radially aligned NiMo alloy microtubes on Ni foam (NiMo MT/NF). The synthesized NiMo alloy catalyst was composed of the Ni10Mo phase; notably, this hierarchically structured material possessed abundant active sites and a high surface area, and exhibited efficient electronic transport properties. The NiMo MT/NF electrode exhibited a low overpotential of 119 mV at 10 mA/cm2 in a base solution, which was 50 mV less than that of NiMo alloy nanoparticles on NF (169 mV). 相似文献
14.
Rebecca L. KingGerardine G. Botte 《Journal of power sources》2011,196(22):9579-9584
It has been shown that urea electrolysis is a viable method for wastewater remediation and simultaneous production of valuable hydrogen. Inexpensive nickel catalyst is optimal for the oxidation of urea in alkaline media but improvements are needed to minimize surface blockage and increase current density. Multi-metal catalysts were investigated by depositing platinum group metals on a nickel substrate. Rhodium and nickel proved synergistic to reduce surface blockage and increase catalyst stability. Rh-Ni electrodes reduced the overpotential for the electro-oxidation of urea and improved the current density by a factor of 200 compared to a Ni catalyst. 相似文献
15.
Cobalt doping VS2 on nickel foam as a high efficient electrocatalyst for hydrogen evolution reaction
《International Journal of Hydrogen Energy》2022,47(19):10646-10653
The development of non-precious metal catalysts with abundant reserves, low prices and good performance for HER is desired. In this work, rodlike Co doping VS2 arrays on nickel foam (NF) (Co-VS2/NF) were fabricated by a simple one-step solvothermal method. Structure characterization indicated that Co doping reduced the size of rodlike Co-VS2 and meanwhile can modulate its electronic structure, which is beneficial for the enhancement of HER performance. The optimal Co-VS2/NF-2 reveals a low overpotential of 164.5 mV at ?10 mA cm?2, small Tafel slope of 52.2 mV dec?1 and excellent long-term stability after 2000 cycles in 1 M KOH. 相似文献
16.
Umair Yaqub Qazi Rahat Javaid Muhammad Zahid Nadeem Tahir Adeel Afzal Xiao-Ming Lin 《International Journal of Hydrogen Energy》2021,46(36):18936-18948
Earth-abundant, non-precious metal-based bifunctional electrocatalysts with efficient water splitting activity are of valuable importance in the limitation of energy losses in an alkaline environment. Herein, we report NiCo–NiCoO2 nano-heterostructures embedded on the oxidized surface of copper foam (NiCo–NiCoO2@Cu2O@CF) as an efficient bifunctional electrocatalyst for overall water splitting in 1 M KOH electrolyte solution. In this study, metallic Ni and Co interlinkage with NiCoO2 nanoparticles (NPs) are suggested to form by thermal decomposition of nickel-cobalt hydroxide precursors embedding on copper foam under a nitrogen environment. Bimetallic thin layered nano-heterostructures of NiCo–NiCoO2@Cu2O@CF exhibits a synergic effect of doubly active metals Ni and Co to achieve remarkable small overpotentials of 133 and 327 mV to achieve a current density of 10 mA cm?2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The influential synergetic and structural effects have been extensively discussed to understand the overall water splitting for designing an efficient electrocatalyst. Hence, this phenomenon for surface modification of conductive substrate (CF) with a suitable combination of metal/metal oxide alloying as catalytic material helps us to design and synthesize low cost, highly efficient, non-precious metal-based electrocatalysts for overall water splitting. 相似文献
17.
《International Journal of Hydrogen Energy》2022,47(39):17252-17262
Heterostructured materials with special interfaces and features give a unique character for much electrocatalytic process. In this work, the introduction of exogenous modifier Ni-MOF improved the reaction kinetics and morphology of the NiCo2O4@Ni-MOF/NF catalyst. As-obtained NiCo2O4@Ni-MOF/NF has excellent oxygen evolution reaction (OER) performance and urea oxidation reaction (UOR) performance. The catalyst need overpotential of 340 mV at a current density of 100 mA cm?2 for OER and a potential of 1.31 V at the same current density for UOR. The Tafel slopes of NiCo2O4@Ni-MOF/NF is 38.34 and 15.33 mV dec?1 for OER and UOR respectively, which is more superior than 78.58 and 66.73 mV dec?1 of NiCo2O4/NF. The nanosheets microstructure is beneficial to the adsorption and transport of electrolyte and the presence of a large number of mesoporous channels can also accelerate gas release, and then improves activity of the catalyst. Density functional theory calculation demonstrate that NiCo2O4 plays a role in absorbing water, while the existence of in situ generated NiOOH can promote the electron transfer efficiency. It is synergies of NiCo2O4 and in situ generated NiOOH that enhance the decomposition of water on the surface of the NiCo2O4@Ni-MOF/NF. This investigation provides a new strategy for the application of spinel oxide and MOF materials. 相似文献
18.
Zhaoxia Yang Rui He Huimin Wu Yu Ding He Mei 《International Journal of Hydrogen Energy》2021,46(15):9690-9698
In this work, CoP/NF is synthesized at different temperature (250 °C, 300 °C, 350 °C) (denoted as CoP/NF-T, T = 250, 300, 350). Then, CoP/NF-300 with the best performance towards hydrogen evolution reaction (HER), is used to synthesize compounds with different ratio of reduced graphene oxide (rGO) (CoP/rGO/NF-X, X (quality ratio of rGO/CoP) = 1,3,5). In terms of morphology, under the synergistic effect of rGO, uniform and dense CoP provides the possibility to increase the electrochemical area. While CoP/rGO/NF-3 shows the minimum overpotential of 136 mV to drive 50 mA/cm, and the smallest Tafel slope 135 mV/dec among as-synthesized materials. Furthermore, CoP/rGO/NF-3 has good stability during at least 25 h. These result can be construed as the large electrochemical active area, high conductivity and long-time stability. 相似文献
19.
Yaqiong Gong Hailong Pan Zhoufeng Xu Zhi Yang Yu Lin Jinlei Wang 《International Journal of Hydrogen Energy》2018,43(36):17259-17264
Great efforts in developing low-cost, highly efficient and stable electrocatalysts are to tune the chemical compositions and morphological characteristics for enhancing efficiency of water splitting. In this communication, FeCo2S4 nanosheet was grown in situ on nickel foam (FeCo2S4/NF) via a facile hydrothermal sulfidization method and served as a high-efficient bifunctional electrocatalyst for overall water splitting. As-synthesized FeCo2S4/NF self-supported electrode delivers 20 mA cm?2 at an overpotential of 259 mV toward OER and 10 mA cm?2 at an overpotential of 131 mV toward HER in alkaline media. Moreover, when used as both anode and cathode in a two-electrode electrolyzer, only a small cell voltage of 1.541 V is needed to afford a current density of 10 mA cm?2 for overall water splitting. Bifunctional electrode FeCo2S4/NF also revealed a distinguished electrochemical durability during a 12 h stability test at 1.63 V, which would provide a promising water splitting installation for commercial hydrogen production. 相似文献
20.
Yihui Wu Yuan Zhang Yuxin Wang Zhen He Zhengjian Gu Shuochao You 《International Journal of Hydrogen Energy》2021,46(53):26930-26939
Ni–Fe–Sn electrocatalyst supported on nickel foam (Ni–Fe–Sn/NF) with high efficiency of hydrogen evolution reaction (HER) has been successfully fabricated through one-step potentiostatic electrodeposition route. The optimized Ni–Fe–Sn/NF displayed an extremely low overpotential of, respectively, 144 and 180 mV at 50 and 100 mA cm?2 for HER in alkaline condition. Moreover, it could retain its superior stability for at least 12 h. The remarkable electrocatalytic activity of our electrocatalyst is ascribed to the high conductivity originated from synergistic effects between Ni, Fe, and Sn during HER process. 相似文献