The reasonable design and construction of non-precious metal electrocatalysts with low cost and high performance is critical for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, a facile polymerization-pyrolysis method is proposed to encapsulate Co2P nanoparticles in co-doped hollow carbon shell by using ZIF-67 and P-containing polymers as precursor. The unique construction not only effectively prevents nanoparticles from detaching, showing good stability after long-term testing, but also provides abundant active sites, large surface areas and large pore volumes, enabling the electrolyte and electrode material to full contact. As expected, the Co2P/NPSC-800 performs superior HER performance with low overpotential of 173 mV at 10 mA cm−2 and excellent stability of 88% retention for 35 h and OER performance with low overpotential of 320 mV at 10 mA cm−2, which endows Co2P/NPSC-800 with good catalytic activity in overall water splitting. Furthermore, density functional theory (DFT) calculations reveal that the metallic property and the decreased reaction barriers of Co2P can promote the catalytic reactions. This work offers an effective route in synthesizing other transition metal phosphides with high catalytic properties. 相似文献
Herein, strongly coupled Ni3S2/MoS2 hollow spheres derived from NiMo-based bimetal-organic frameworks are successfully synthesized for overall water splitting via a one-pot solvothermal method followed by sulfurization. A well-defined hollow spherical structure with a heterointerface between Ni3S2 and MoS2 is constructed using solvothermal and sulfurization processes. Owing to their bimetallic heterostructure, porous hollow carbon structure with large surface area, and numerous exposed active sites, the Ni3S2/MoS2 hollow spheres are found to be efficient electrocatalysts for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The heterostructured Ni3S2/MoS2 hollow spheres show small overpotentials of 303 and 166 mV to reach a current density of 10 mA cm?2 for the OER and HER in 1.0 M KOH, respectively. Furthermore, an overall water-splitting electrolyzer consisting of the Ni3S2/MoS2 hollow spheres as both the anode and cathode requires a very low cell voltage of 1.62 V to drive a current density of 10 mA cm?2 with outstanding long-term stability for 100 h. Our findings offer a new pathway for the design and synthesis of electrochemically advanced bifunctional catalysts for various energy storage and conversion applications. 相似文献
Environmentally friendly overall water splitting electrocatalysts can be exploited through construction of efficient heterogeneous interfaces. Flexible preparation of lattice-matching Ni2P–Co2P heterointerfaces is exploited to promote electrochemical activity for overall water splitting because of the outstanding electrical conductivity of Co2P and admirable durability of Ni2P. Density functional theory calculations demonstrate that construction of lattice-matching Ni2P–Co2P heterogeneous interfaces and the regulation of density of states between the heterogeneous interfaces can effectively optimize the water adsorption energy. Hence, a series of NixP-Co2P hybrid materials were in site grown on nickel foam through hydrothermal synthesis and phosphorization approach. What is noteworthy is that the Ni2P–Co2P-0.5//Ni2P–Co2P-1 electrode couple presents superior electrochemical performance with only 1.60 V cell voltage to obtain a current density of 10 mA cm?2 under alkaline condition. In addition, the Ni2P–Co2P-0.5//Ni2P–Co2P-1 electrode couple display superior durability over 15 h at large current densities of 30 mA cm?2 during water electrolysis process. The construction of heterostructures is conducive to the regulation of state density and the maximization of synergistic catalytic effect. The work provides a novel idea for the exploitation of highly efficient and robust water electrolysis catalysts and this work might be a new breakthrough for the construction of lattice-matching hybrid structures. 相似文献
This work demonstrates a facile Nb2O5-decorated electrocatalyst to prepare cost-effective Ni–Fe–P–Nb2O5/NF and compared HER & OER performance in alkaline media. The prepared electrocatalyst presented an outstanding electrocatalytic performance towards hydrogen evolution reaction, which required a quite low overpotential of 39.05 mV at the current density of ?10 mA cm?2 in 1 M KOH electrolyte. Moreover, the Ni–Fe–P–Nb2O5/NF catalyst also has excellent oxygen evolution efficiency, which needs only 322 mV to reach the current density of 50 mA cm?2. Furthermore, its electrocatalytic performance towards overall water splitting worked as both cathode and anode achieved a quite low potential of 1.56 V (10 mA cm?2). 相似文献
A Ni–CoSe2/BCT composite composed of biomass-derived carbon tubes and transition metal selenides was successfully constructed and explored as a highly efficient bifunctional electrocatalyst for overall water splitting.
Electrocatalytic water splitting is identified as one of the most promising solutions to energy crisis. The CoSe2@NiSe2 materials were first prepared and in situ grown on nickel foam by typical hydrothermal and selenification process at 120 °C. The results show that the CoSe2@NiSe2 material used as the 3D substrates electrode can maximize the synergy between the CoSe2 and NiSe2, and also exhibits high efficiency of water splitting reaction. The lower overpotential of only 235 mV is presented to attain 20 mA cm−2 compared to the benchmark of RuO2 electrodes (270 mV @ 20 mA cm−2). Besides, the CoSe2@NiSe2 material also shows a remarkable improved hydrogen evolution reaction activity compared to NiSe2 (192 mV@10 mA cm−2) and Co precursor catalysts (208 mV@10 mA cm−2) individually, which a low overpotential of only 162 mV is achieved at 10 mA cm−2. The CoSe2@NiSe2 catalysts exhibit excellent water splitting performance (cell voltage of 1.50 V@ 10 mA cm−2) under alkaline conditions. It was proved that the high water splitting performance of the catalyst is attributed to high electrochemical activity area and synergistic effect. The work offers new ideas for the exploitation of synergistic catalysis of composite catalysts and adds new examples for the exploitation of efficient, better and relatively non-toxic electrocatalysts. 相似文献
Constructing efficient bifunctional electrocatalysts for both cathode and anode is of great importance for obtaining green hydrogen by water splitting. Herein, sulfuration of hierarchical Mn-doped NiCo LDH heterostructures (Mn–NiCoS2/NF) is constructed as a bifunctional electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) via a facile hydrothermal-annealing strategy. Mn–NiCoS2/NF shows an overpotential of 310 mV at 50 mA cm−2 for OER and 100 mV at 10 mA cm−2 for HER in 1.0 M KOH. Moreover, only 1.496 V@10 mA cm−2 is required for overall water splitting by using Mn–NiCoS2/NF as catalyst dual electrodes in a two-electrode system. The excellent performance of Mn–NiCoS2/NF should be attributed to the ameliorative energy barriers of adsorption/desorption for HO−/H2O through the modification of electronic structure of NiCo basal plane by Mn-doping and the acceleration of water dissociation steps via rich delocalized electron inside sulfur vacancies. The construction of hierarchical Mn–NiCoS2/NF heterostructures provides new prospects and visions into developing efficient-advanced electrocatalysts for overall water splitting. 相似文献
Water electrolysis to generate hydrogen (H2) and oxygen (O2) was a sustainable alternative for clean energy in the future but remained challenging. Herein, we fabricated a nanoneedle-like CoP core coated by a P,N-codoped carbon shell (CoP@PNC@NF). The hierarchical structure, unique nanoneedle-like morphology, CoP core, and P,N-codoped carbon shell were responsible for the high electrocatalytic activity. Electrocatalytic tests demonstrated that CoP@PNC@NF displayed low overpotentials of 137.6 and 148.4 mV, as well as Tafel slopes of 59.89 and 56.40 mV dec−1 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, at 10 mA cm−2 in 1.0 M KOH. The bifunctional electrocatalyst CoP@PNC@NF also exhibited a low cell voltage of 1.458 V to yield 10 mA cm−2 in the two-electrode system and could maintain the activity for 50 h. The Faradaic efficiencies of CoP@PNC@NF for both HER and OER were nearly 100%. The result outperformed the precious-metal-based electrocatalyst apparatus (RuO2||Pt/C) and other carbon-coated transition-metal phosphides (TMPs). This work paved the way for the rational design of carbon shell-coated TMPs with low energy barriers for converting and storing electrochemical energy. 相似文献
a low-cost electrode with lawn-like NiS2 nanowire arrays on flexible carbon fiber paper was synthesized, for the first time, via sulfurization of Ni2(CO3)(OH)2 precursor. And the performance of this electrode as a bifunctional electrocatalyst toward both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) was evaluated. It shows that NiS2 NWs/CFP requires small overpotentials of 165 mV for HER and 246 mV for OER, respectively, to deliver the current density of 10 mA cm?2 in 1.0 M KOH. The corresponding symmetric two-electrode alkaline water electrolyzer only needs a cell voltage of 1.59 V to afford 10 mA cm?2 water-splitting current density. 相似文献
Searching for efficient, stable and low-cost nonprecious catalysts for oxygen and hydrogen evolution reactions (OER and HER) is highly desired in overall water splitting (OWS). Herein, presented is a nickel foam (NF)-supported MoS2/NiFeS2 heterostructure, as an efficient electrocatalyst for OER, HER and OWS. The MoS2/NiFeS2/NF catalyst achieves a 500 mA cm−2 current density at a small overpotential of 303 mV for OER, and 228 mV for HER. Assembled as an electrolyzer for OWS, such a MoS2/NiFeS2/NF heterostructure catalyst shows a quite low cell voltage (≈1.79 V) at 500 mA cm−2, which is among the best values of current non-noble metal electrocatalysts. Even at the extremely large current density of 1000 mA cm−2, the MoS2/NiFeS2/NF catalyst presents low overpotentials of 314 and 253 mV for OER and HER, respectively. Furthermore, MoS2/NiFeS2/NF shows a ceaseless durability over 25 h with almost no change in the cell voltage. The superior catalytic activity and stability at large current densities (>500 mA cm−2) far exceed the benchmark RuO2 and Pt/C catalysts. This work sheds a new light on the development of highly active and stable nonprecious electrocatalysts for industrial water electrolysis. 相似文献
The development of clean energy technologies to protect the environment is an important demand of the times. Electrocatalysis is emerging as a promising method for evolution of hydrogen and overall water splitting. Nowadays, metal organic frameworks (MOFs) have emerged as electrocatalysts having uniformly distributed active sites and high electrical conductivity. This review summarizes the latest advances in heterogeneous catalysis by MOFs and their composite/derivatives for efficient hydrogen evolution reaction (HER) and water splitting. Pristine MOFs with their recent development are summarized first followed by composites of MOFs with their enhanced electrocatalytic performances. Overall water splitting by using bifunctional electrocatalysts derived from MOFs with different synthetic approaches is provided and this review gives the metal-based categorisation of precursor MOFs. Different strategies to improve chemical stability, conductivity, and overall electrocatalytic properties have been discussed. In the last, perspectives on the synthesis of efficient MOF-based electrocatalyst materials are provided. 相似文献
Electrocatalytic water splitting technology has become one of the most promising methods to solve the energy crisis, which can produce a large amount of high purity H2 and O2. It is necessary to develop efficient and stable water splitting catalyst for reducing the overpotential of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) and accelerating their reaction kinetics. A series of NiSe2@NixSy nanoarrays was firstly in situ grown on the nickel foam through the typical hydrothermal, selenylation and sulfuration pathways. The Na2SeO3 homogeneous solution is formed by hydrothermal and the selenization process is done at the temperature of 180。C. Then the nickel foam (NF) is put into the Na2SeO3 solution to form NiSe2 material at the temperature of 120。C. After that, the NiSe2 materials were sulfuretted with different amounts of sulfur to form NiSe2@NixSy hybrid materials. The experimental results demonstrate that the NiSe2@NixSy material as a 3D electrode can maximize the synergistic reaction between NiSe2 and NixSy, thus exhibiting an efficient and comprehensive water splitting performance. The NiSe2@NixSy-1 material presents a superior OER performance with requiring the overpotential of only 206 mV at 100 mA cm−2. Moreover, the NiSe2@NixSy-0.3 material presents a superior HER performance with requiring the overpotential of only 148 mV at 100 mA cm−2. It is worth noting that when NiSe2@NixSy-1 material and the NiSe2@NixSy-0.3 material was used as cathode and anode, only 1.53 V cell voltage is needed to produce a current density of 10 mA cm−2 throughout the water splitting process, which is one of the smallest values reported so far. Density functional theory calculations results show that the Ni3S2 has the best water adsorption energy, so it is an active species in the process of catalysis. However, NiSe2 has more density distribution around the Fermi level, indicating that it exhibits better metallic properties, which makes the NiSe2@NixSy-1 hybrid material exhibit better electronic conductivity. 相似文献
An attractive approach to obtain effective and stable electrode for water electrolysis is to directly deposit the electrocatalyst on current collector surface. Herein, we show the influence of electrochemical activation of carbon cloth substrate on the morphology and electrocatalytic properties of bifunctional electrodes for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). A simple one-step electrodeposition technique was applied to directly grow mixed Co-based films on electrochemically activated carbon cloth (EACC) surface. The produced films are composed of metallic Co, and largely amorphous CoO/Co(OH)2 phases. Variation of Co2+ concentration in the solution for electrodeposition enabled tuning the composition of mixed films in order to achieve the optimal HER and OER electrocatalytic performance in 0.1 M KOH. The synthesized electrodes require the overpotentials of 195 mV for HER and 340 mV for OER to deliver the current density of 10 mA/cm2. The results indicate that the facile oxidation of carbon cloth prior to the electrodeposition decreases the overpotential at 10 mA/cm2 by 150 and 60 mV for HER and OER respectively, thus opening the perspective of improving the activity of carbon-based self-supported composite electrocatalytic electrodes for advanced energy conversion processes. 相似文献
The development of bifunctional catalysts that can be applied to both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is widely regarded as a key factor in the production of sustainable hydrogen fuel by electrochemical water splitting. In this work, we present a high-performance electrocatalyst based on nickel-cobalt metal-organic frameworks for overall water splitting. The as-obtained catalyst shows low overpotential to reaches the current density of 10 mA cm−2 with 249 mV for OER and 143 mV for HER in alkaline media, respectively. More importantly, when the electrolyzer was assembled with the as-prepared catalyst as anode and cathode simultaneously, it demonstrates excellent activity just applies a potential of 1.68 V to achieve 10 mA cm−2 current density for overall water splitting. 相似文献
The need for a clean and an environmentally non-degrading sustainable energy resource has grown worldwide due to the huge depletion of other fuel sources, as a result, production of hydrogen by electrochemical water splitting is considered as a potential answer to this pertaining need. However, development of low-cost electrocatalyst as a replacement for Pt and RuO2 for both Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) remains a significant challenge for the production of hydrogen at a larger scale. This study presents the synthesis of non-noble metal-based lanthanum doped copper oxide nanoparticles as a potential bi-functional electrocatalyst for overall water splitting in alkaline electrolyte. The optimized 1% lanthanum (La) doped CuO electrocatalyst exhibits outstanding OER and HER activity in 1.0 M KOH electrolyte posting a potential of 1.552 V vs RHE for OER and −0.173 V vs RHE for HER at a current density of ~10 mAcm−2. Significantly, the functional bi-catalyst exhibits a low cell voltage of 1.6 V to achieve overall water splitting at a current density of 10 mAcm−2 along with long-term stability of 13.5 h for a cell voltage of 2.25 V at a constant current density of 30 mAcm−2 with only 20% initial current lose after 13.5 h. The results demonstrate that the incorporation of the rare-earth element onto CuO nanoparticles has made it a viable high-end non-noble electrocatalyst for overall water splitting. 相似文献
Designing high-efficiency catalysts for overall water splitting is critical to reduce the cost of hydrogen fuel as a clean and renewable energy source in future society. In this work, a Mo-, P-codoped NiFeSe was successfully synthesized on nickel foam (NF) by one-step electrodeposition. Through the doping strategy, the conductivity can be well promoted, and the production of nanosheets on the catalyst surface and active phases during hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) provided much more active sites, which leaded to efficient HER/OER performances of as-synthesized Mo-, P-codoped NiFeSe catalysts, i.e., a low overpotential of 100 mV/200 mV at current density of 10 mA cm−2 in 1.0 M KOH with stability of 95 h/60 h, respectively. It only required 1.53 V to deliver a current density of 10 mA cm−2 in overall water splitting and maintained outstanding durability for 100 h. This work is beneficial to future design of high efficient and low-cost bifunctional catalysts for overall water splitting. 相似文献
Electrochemical water splitting technique requires high-efficient bifunctional electrocatalysts to obtain large-scale hydrogen production for resolving the impending energy and environmental crisis. Herein, hierarchical flower-like CoS2-MoS2 heterostructure hybrid spheres grown on carbon cloth (CoS2-MoS2/CC) were prepared by sulfuring wheel-shaped polyoxometalate {Co20Mo16}. The as-prepared CoS2-MoS2/CC as bifunctional electrocatalyst manifests excellent alkaline oxygen evolution and hydrogen evolution activities with low overpotentials of 240 mV for OER and 60 mV for HER at 10 mA cm?2, respectively. When assembled as two-electrode cell, CoS2-MoS2/CC delivers an extremely low cell-voltage of 1.52 V at 10 mA cm?2 accompanied with remarkable long-term durability. Additionally, CoS2-MoS2/CC exhibits favorable overall-water-splitting performance in simulated seawater. The superior performance of CoS2-MoS2/CC should be ascribed to the optimized intrinsic electron structure via electron transfer from MoS2 to CoS2 along with the synergistic effect of well-exposed heterostructure interfaces and favorable diffusion channels. This work offers a practical strategy for exploring high-efficient bifunctional electrocatalysts for overall water splitting. 相似文献
Electrochemical water electrolyser though an assuring solution for clean hydrogen production, the sluggish kinetics and high cost of existing precious metal electrocatalyst remains a barrier to its effective utilization. Herein, solution combustion route derived perovskite type barium nickelate (BaNiO3) nanoparticles were developed and studied for their bifunctional electrocatalytic properties towards overall water splitting. The unannealed BaNiO3 nanoparticles exhibited the highest OER and HER activity with overpotentials 253 mV and 427 mV respectively to attain 10 mAcm−2 in 1.0 M KOH. Using unannealed BaNiO3 as a bifunctional electrocatalyst in a two-electrode alkaline electrolyser, the cell was able to achieve the benchmark current density at a low cell voltage of 1.82 V. Impressively the setup's electrocatalytic performance improved 4.9% after continuous overall water splitting for 24 h at 30 mAcm−2. Therefore, BaNiO3 nanoparticles can be a low-cost and efficient alternative for noble metal electrocatalysts for clean H2 production. 相似文献
Constructing efficient and stable bifunctional electrocatalysts for overall water splitting remains a challenge because of the sluggish reaction kinetics. Herein, the core-shell hybrids composed of Co(PO3)2 nanorod core and NiFe alloy shell in situ grown on nickel foam (NiFe/Co(PO3)2@NF) are synthesized. Owing to the hierarchical palm-leaf-like structures and strong adhesion between NiFe alloys, Co(PO3)2 and substrates, the catalyst provides a large surface area and rapid charge transfer, which facilitates active sites exposure and conductivity enhancement. The interfacial effect in the NiFe/Co(PO3)2 core-shell structure modulates the electronic structure of the active sites around the boundary, thereby boosting the intrinsic activity. Benefiting from the stable structure, the durability of the catalyst is not impaired by the inevitable surface reconfiguration. The NiFe/Co(PO3)2@NF electrode presents a low cell voltage of 1.63 V to achieve 10 mA cm?2 and manifests durability for up to 36 h at different current densities. 相似文献
In this work, we developed ternary metallic cobalt-cobalt nitride-dicobalt phosphide composite embedded in nitrogen and phosphorus co-doped carbon (Co/CoN/Co2P-NPC) as bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The as-prepared Co/CoN/Co2P-NPC is achieved by simultaneous annealing and phosphating of a Co–N rich metal-organic frameworks (MOFs) precursor. Compare with the phosphorus-free Co/CoN embedded nitrogen-doped carbon electrocatalyst (Co/CoN-NC), the as-prepared Co/CoN/Co2P-NPC display superior HER and OER low overpotential of 99 mV and 272 mV at current density of 10 mA cm−2. When Co/CoN/Co2P-NPC electrocatalyst is use as bifunctional catalysts in overall alkaline water splitting, it exhibit excellent behaviour with 10 mA cm−2 current at overall cell potential of 1.60 V. The excellent performance of Co/CoN/Co2P-NPC electrocatalyst is attributed to the phosphating process that could further enhance synergistic effect, create stronger electronic interactions, and form efficient dual heteroatom doping to optimize the interfacial adhesion within the electrocatalyst. This present work will create more opportunities for the development of new, promising and more active sites electrocatalysts for alkaline electrolysis. 相似文献