Hairy sphere-like Ni9S8/CuS/Cu2O composites grown on nickel foam as bifunctional electrocatalysts for hydrogen evolution and urea electrooxidation
TL;DR: In this paper, a dual-electrode urea solution electrolytic cell was constructed based on the bifunctional properties of Ni9S8/CuS/Cu2O/NF, which only needed a low voltage of 1.47
About: This article is published in International Journal of Hydrogen Energy.The article was published on 2021-06-11. It has received 34 citations till now. The article focuses on the topics: Electrocatalyst & Water splitting.
Citations
More filters
TL;DR: In this article , the Ni-based powder catalysts for urea-assisted hydrogen generation via water splitting were reviewed and the main fabrication approaches were summarized and discussed, and the problems and challenges were also concluded for the Nibased powder catalyst fabrication, the performance evaluation, and their application.
Abstract: Water splitting has been regarded as a sustainable and environmentally-friendly technique to realize green hydrogen generation, while more energy is consumed due to the high overpotentials required for the anode oxygen evolution reaction. Urea electrooxidation, an ideal substitute, is thus received increasing attention in assisting water-splitting reactions. Note that highly efficient catalysts are still required to drive urea oxidation, and the facile generation of high valence state species is significant in the reaction based on the electrochemical-chemical mechanisms. The high cost and rareness make the noble metal catalysts impossible for further consideration in large-scale application. Ni-based catalysts are very promising due to their cheap price, facile structure tuning, good compatibility, and easy active phase formation. In the light of the significant advances made recently, herein, we reviewed the recent advances of Ni-based powder catalysts for urea oxidation in assisting water-splitting reaction. The fundamental of urea oxidation is firstly presented to clarify the mechanism of urea-assisted water splitting, and then the prevailing evaluation indicators are briefly expressed based on the electrochemical measurements. The catalyst design principle including synergistic effect, electronic effect, defect construction and surface reconstruction as well as the main fabrication approaches are presented and the advances of various Ni-based powder catalysts for urea assisted water splitting are summarized and discussed. The problems and challenges are also concluded for the Ni-based powder catalysts fabrication, the performance evaluation, and their application. Considering the key influencing factors for catalytic process and their application, attention should be given to structure−property relationship deciphering, novel Ni-based powder catalysts development and their construction in the real device; specifically, the effort should be directed to the Ni-based powder catalyst with multi-functions to simultaneously promote the fundamental steps and high anti-corrosion ability by revealing the local structure reconstruction as well as the integration in the practical application. We believe the current summarization will be instructive and helpful for the Ni-based powder catalysts development and understanding their catalytic action for urea-assisted hydrogen generation via water splitting technique. Advances and challenges of Ni based powder catalyst were reviewed for urea oxidation in assisting water-splitting reaction.
85 citations
TL;DR: In this article, a simple "cyclic voltammetry + ageing" protocol was proposed to activate Ni electrode (AC-Ni/NF) for hydrogen evolution reaction (HER), by which Ni/Ni(OH)2 heterostructure is formed at the surface.
36 citations
TL;DR: In this article, NiMoSe ternary nanospheres were deposited on nickel foam (NiMoSe/NF) by one-step electrodeposition, and the morphology, phase and chemical composition of the electrode was characterized by using SEM, TEM, XRD and XPS.
21 citations
TL;DR: In this paper , a one-step hydrothermal method was used to produce a composite with high-frequency electromagnetic wave absorption in the Ku band with a minimum reflection loss of − 58.74 dB at 17.52 GHz and a matching thickness of 4.64 mm.
19 citations
TL;DR: In this paper , the Schikorr reaction was used to deposit Fe3O4 particles on the nickel foam (Fe 3O4/NF), and the surface reconstruction was performed to produce a heterolayered structure wherein a catalytically active FeOOH layer encased a conducting Fe3 O4.
15 citations
References
More filters
TL;DR: The topotactic fabrication of self-supported nanoporous cobalt phosphide nanowire arrays on carbon cloth via low-temperature phosphidation of the corresponding Co(OH)F/CC precursor offers excellent catalytic performance and durability under neutral and basic conditions.
Abstract: In this Communication, we report the topotactic fabrication of self-supported nanoporous cobalt phosphide nanowire arrays on carbon cloth (CoP/CC) via low-temperature phosphidation of the corresponding Co(OH)F/CC precursor. The CoP/CC, as a robust integrated 3D hydrogen-evolving cathode, shows a low onset overpotential of 38 mV and a small Tafel slope of 51 mV dec–1, and it maintains its catalytic activity for at least 80 000 s in acidic media. It needs overpotentials (η) of 67, 100, and 204 mV to attain current densities of 10, 20, and 100 mA cm–2, respectively. Additionally, this electrode offers excellent catalytic performance and durability under neutral and basic conditions.
2,063 citations
TL;DR: In this article, the hydrogen (H2) and oxygen (O2) fuel cell is the one with zero carbon emission and water as the only byproduct, which is essential to ensure higher life cycle and less decay in cell efficiency.
Abstract: Increasing demand for finding eco-friendly and everlasting energy sources is now totally depending on fuel cell technology. Though it is an eco-friendly way of producing energy for the urgent requirements, it needs to be improved to make it cheaper and more eco-friendly. Although there are several types of fuel cells, the hydrogen (H2) and oxygen (O2) fuel cell is the one with zero carbon emission and water as the only byproduct. However, supplying fuels in the purest form (at least the H2) is essential to ensure higher life cycles and less decay in cell efficiency. The current large-scale H2 production is largely dependent on steam reforming of fossil fuels, which generates CO2 along with H2 and the source of which is going to be depleted. As an alternate, electrolysis of water has been given greater attention than the steam reforming. The reasons are as follows: the very high purity of the H2 produced, the abundant source, no need for high-temperature, high-pressure reactors, and so on. In earlier days,...
1,757 citations
TL;DR: In this paper, the NiCo2S4 NW/NF arrays on a 3D Ni foam (NF) were used for solar-to-hydrogen (S2H) generation, achieving a hydrogen production current density of 10 mA cm-2 at an overpotential of 260 mV for the oxygen evolution reaction and at 210 mV (versus a reversible hydrogen electrode).
Abstract: A recent approach for solar-to-hydrogen generation has been water electrolysis using efficient, stable, and inexpensive bifunctional electrocatalysts within strong electrolytes. Herein, the direct growth of 1D NiCo2S4 nanowire (NW) arrays on a 3D Ni foam (NF) is described. This NiCo2S4 NW/NF array functions as an efficient bifunctional electrocatalyst for overall water splitting with excellent activity and stability. The 3D-Ni foam facilitates the directional growth, exposing more active sites of the catalyst for electrochemical reactions at the electrode–electrolyte interface. The binder-free, self-made NiCo2S4 NW/NF electrode delivers a hydrogen production current density of 10 mA cm–2 at an overpotential of 260 mV for the oxygen evolution reaction and at 210 mV (versus a reversible hydrogen electrode) for the hydrogen evolution reaction in 1 m KOH. This highly active and stable bifunctional electrocatalyst enables the preparation of an alkaline water electrolyzer that could deliver 10 mA cm–2 under a cell voltage of 1.63 V. Because the nonprecious-metal NiCo2S4 NW/NF foam-based electrodes afford the vigorous and continuous evolution of both H2 and O2 at 1.68 V, generated using a solar panel, they appear to be promising water splitting devices for large-scale solar-to-hydrogen generation.
1,152 citations
TL;DR: In this article, three-dimensional (3D) porous Ni/Ni8P3 and Ni/N9S8 electrodes are prepared by sequential treatment of commercial Ni-foam with acid activation, followed by phosphorization or sulfurization, which can act as self-supported bifunctional electrocatalytic electrodes for direct water splitting with excellent activity toward oxygen evolution reaction and hydrogen evolution reaction in alkaline media.
Abstract: Development of easy-to-make, highly active, and stable bifunctional electrocatalysts for water splitting is important for future renewable energy systems. Three-dimension (3D) porous Ni/Ni8P3 and Ni/Ni9S8 electrodes are prepared by sequential treatment of commercial Ni-foam with acid activation, followed by phosphorization or sulfurization. The resultant materials can act as self-supported bifunctional electrocatalytic electrodes for direct water splitting with excellent activity toward oxygen evolution reaction and hydrogen evolution reaction in alkaline media. Stable performance can be maintained for at least 24 h, illustrating their versatile and practical nature for clean energy generation. Furthermore, an advanced water electrolyzer through exploiting Ni/Ni8P3 as both anode and cathode is fabricated, which requires a cell voltage of 1.61 V to deliver a 10 mA cm(-2) water splitting current density in 1.0 M KOH solution. This performance is significantly better than that of the noble metal benchmark-integrated Ni/IrO2 and Ni/Pt-C electrodes. Therefore, these bifunctional electrodes have significant potential for realistic large-scale production of hydrogen as a replacement clean fuel to polluting and limited fossil-fuels.
782 citations
TL;DR: In this paper, a representative selenide catalyst is entirely converted into nickel hydroxide under oxygen-evolution conditions, showing that metal selenides are unstable during oxygen evolution, and the in situ generated metal oxides are responsible for their activity.
Abstract: Efficient oxygen-evolution reaction catalysts are required for the cost-effective generation of solar fuels. Metal selenides have been reported as promising oxygen-evolution catalysts; however, their active forms are yet to be elucidated. Here we show that a representative selenide catalyst, nickel selenide, is entirely converted into nickel hydroxide under oxygen-evolution conditions. This result indicates that metal selenides are unstable during oxygen evolution, and the in situ generated metal oxides are responsible for their activity. This knowledge inspired us to synthesize nanostructured nickel iron diselenide, a hitherto unknown metal selenide, and to use it as a templating precursor to a highly active nickel iron oxide catalyst. This selenide-derived oxide catalyses oxygen evolution with an overpotential of only 195 mV for 10 mA cm(-2). Our work underscores the importance of identifying the active species of oxygen-evolution catalysts, and demonstrates how such knowledge can be applied to develop better catalysts.
779 citations