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Rational design of manganese cobalt phosphide with yolk‐shell structure for overall water splitting
摘要： The development of low cost, earth-abundant and efficient catalysts for overall water splitting, involving hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), attracts tremendous attention in recent years. Herein, this work reports the preparation of Mn-Co phosphide (Mn-Co-P) bifunctional catalysts with a yolk-shell structure by a facile hydrothermal route. The as-prepared catalysts exhibit excellent catalytic activity with low overpotentials of 66 mV at 10 mA cm-2 for HER and 355 mV at 50 mA cm-2 for OER in 1 M KOH, along with outstanding stability. More importantly, the cell voltage of 1.74 V can achieve the current density of 10 mA cm-2 when assembled as an electrolyzer for overall water splitting. Such superior performance makes the Mn-Co-P being a promising candidate to replace Pt-based noble metal catalysts for electrocatalytic applications.
关键词： yolk-shell structure,electrochemistry,Mn-Co phosphide,overall water splitting,bifunctional catalyst
更新于2025-11-21 11:01:37
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Photocatalytic overall water splitting on isolated semiconductor photocatalyst sites in an ordered mesoporous silica matrix: A multiscale strategy
摘要： Photocatalytic overall water splitting (OWS) in a stoichiometric ratio has attracted increasing attention for the realization of a sustainable, environmentally friendly future. However, this reaction exhibits sluggish kinetics due to efficiency limitations of the involved steps, including photon absorption, electron transfer, and the reactions that occur at triple-phase boundary regions. Herein, we report a general multiscale strategy to address this challenge by designing a model composite catalyst with a high loading density of isolated Bi0.5Y0.5VO4 nanocrystals, as building blocks, dispersed in a hexagonally ordered mesoporous silica matrix. In contrast to the well-recognized heterojunction formed between different semiconductors, we show that confined growth favours the formation of isolated quaternary solid-solution photocatalysts (Bi0.5Y0.5VO4), which can further interface with the insulating silica to overcome temperature limitations and exhibit enhanced photon absorption and electrochemical and mass transfer properties due to the transparent periodic porous structure of silica and the as-formed small nanocrystals with high crystallinity and a passivated surface. When the semiconductor photocatalyst is incorporated with the inert silica insulator, this nanoarchitecture does not inhibit the OWS activity but actually delivers a 10-fold higher OWS activity than bulk Bi0.5Y0.5VO4 prepared by the conventional solid-state method.
关键词： Multiscale strategy,Photocatalysis,Isolated solid-solution nanocrystal,Overall water splitting,Mesoporous composite
更新于2025-09-23 15:23:52
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Constructing 3D sub-micrometer CoO octahedrons packed with layered MoS2 shell for boosting photocatalytic overall water splitting activity
摘要： A 3D architectures of CoO@MoS2 composite photocatalyst was prepared by coating MoS2 onto the (1 1 1) facts of sub-micrometer CoO octahedrons via a facile solvothermal method. The CoO@MoS2 composites show a significantly improved photocatalytic activity for overall water splitting. At an optimal ratio of 3 wt% MoS2, CoO@MoS2-3% composite can split pure water with the stoichiometric ratio production of H2 and O2 under visible light irradiation, meanwhile, presents the highest H2 production evolution (1.07 μmol/h), which is almost four times than that of pure CoO (0.26 μmol/h). Moreover, the CoO@MoS2 composite still remains good stability after three successive cyclings (over 72 h). The enhanced photocatalytic activity and stability can be attributed that the layered MoS2 shell not only promoted the photo-induced charge transfer at the interface of CoO due to the sufficient contact area between CoO and MoS2, but also protected the exposed the (1 1 1) facts of CoO from devastation. Our work offers more insights into the development of a simple synthesis of well-shaped 3D-based composite photocatalysts towards the energy- and environmental-related applications.
关键词： CoO octahedrons,MoS2,Overall water splitting,Core-shell,Visible light
更新于2025-09-23 15:23:52
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Reaction Packaging CoSe <sub/>2</sub> Nanoparticles in N-Doped Carbon Polyhedra with Bifunctionality for Overall Water Splitting
摘要： Water electrolysis is a promising approach for green and large-scale hydrogen production; however, there are still challenges for developing efficient and stable bi-functional electrocatalysts towards the hydrogen and oxygen evolution reactions. Herein, zeolitic imidazolate framework-67 (ZIF67) was used as the precursor for the construction of CoSe2 nanoparticles trapped in N-doped carbon polyhedra (NC). Among as-obtained CoSe2-NC hybrid, highly active CoSe2 nanoparticles in sizes of 10-20 nm are encapsulated in N-doped few-layer carbon shell, avoiding their easy aggregations of CoSe2 nanoparticles as well as enhancing the long-term stability. The unique nanostructured CoSe2-NC hybrid with a hierarchical porosity and 3D conductive framework thus fully exerts outstanding bi-functional catalytic activity of CoSe2 centers. As a result, the CoSe2-NC hybrid as bi-functional catalysts for overall water splitting delivers a high current density of 50 mA cm-2 with applied voltage of ~1.73 V in alkaline electrolyte, with a promising stability over 50000 s.
关键词： selenide reaction,ZIF67,bifunctional electrocatalyst,overall water splitting,carbon polyhedra
更新于2025-09-23 15:22:29
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Photocatalytic Overall Water Splitting on RuO <sub/>2</sub> -loaded Sm <sup>3+</sup> -doped CeO <sub/>2</sub> with Heterogenous Doping Structure
摘要： Photocatalytic overall water splitting into hydrogen and oxygen on RuO2-loaded Sm3+-doped CeO2 was examined. Pure CeO2 showed a negligible small activity, however Sm3+ doped CeO2 with heterogeneous doping structure synthesized by solid state reaction exhibited an efficient activity. Whereas, Sm3+-doped CeO2 with homogeneous doping structure showed little activity when prepared by co-precipitation method. In this study, relation between photocatalytic activity and surface doping structure was investigated.
关键词： Heterogeneous doping structure,Semiconductor photocatalyst,Overall water splitting
更新于2025-09-23 15:22:29
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Novel Porous Boron Nitride Nanosheet with Carbon Doping: Potential Metal-Free Photocatalyst for Visible-Light-Driven Overall Water Splitting
摘要： The band gap of hexagonal boron nitride (h-BN) is far too wide for efficiently utilizing visible light, limiting its application in photocatalysis. The present study employs first principles calculations to demonstrate that the band gap energies of porous h-BN (p-BN) can be tuned by carbon doping to levels appropriate for the absorption of visible-light, and that the conduction band and valence band match well with the potentials of both hydrogen and oxygen evolution reactions. Importantly, a strategy of carbon doping to improve the energy level of valence band maximum is also proposed. Moreover, the carbon-doped p-BN exhibits good separation between photogenerated electrons/holes and structural stability at high temperatures. The DFT results help the design of high-performance two-dimensional photocatalysts that avoid the use of metals.
关键词： metal-free catalysts,photocatalyst,porous boron nitride nanosheets,overall water splitting,band structure engineering
更新于2025-09-23 15:22:29
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Promotion of Overall Water Splitting Activity Over a Wide pH Range by Interfacial Electrical Effects of Metallic NiCo-nitrides Nanoparticle/NiCo <sub/>2</sub> O <sub/>4</sub> Nanoflake/graphite Fibers
摘要： Many efforts have been made to develop bifunctional electrocatalysts to facilitate overall water splitting. Here, a fibrous bifunctional 3D electrocatalyst is reported for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) with high performance. The remarkable electrochemical performance is attributed of the catalysts to a number of factors: the metallic character of the three components (i.e., Ni3N, CoN, and NiCo2O4); the electronic structure, nanoflake-nanosphere network with abundant electroactive sites, and the electric field effect at the interfaces between different components. The oxide–nitride/graphite fibers have the lowest overpotential requirements of 71 and 183 mV at 10 mA cm?2 for HER and OER in alkaline medium, respectively. These values are comparable to those of commercial Pt/C (20 wt%) and RuO2. The electrodes also show a response to HER and OER in both neutral and acid media. Furthermore, the 3D structure can be highlighted by all-round electrodes for overall water splitting. The calculations on the changes in electrons transfer and the Femi level from oxides to oxides/nitrides reveal that the observed superb electrocatalytic performance can be attributed to the presence of Ni3N and CoN derived from the in situ nitridation of NiCo2O4.
关键词： electrocatalysts,overall water splitting,interfacial electrical effects
更新于2025-09-23 15:22:29
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Cobalt/Molybdenum Phosphides and Oxides Heterostructures Encapsulated in N-doped Carbon Nanocomposite for Overall Water Splitting in Alkaline Media
摘要： The development of designing and searching inexpensive electrocatalysts with highly activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is significant to enable water splitting as a future renewable energy source. Herein, we synthesis a new CoP(MoP)-CoMoO3 heterostructure coated by N-doped carbon shell (CoP(MoP)-CoMoO3@CN) via thermal decomposing and phosphatizing the CoMoO4?0.9H2O nanowires encapsulated in N-doped carbon. At 10 mA?cm?2, this CoP(MoP)-CoMoO3@CN nanocomposite exhibits superior electrocatalytic activity of low overpotentials of 296 mV for OER and 198 mV for HER in alkaline media. More importantly, we achieve a current density of 10 mA?cm?2 at 1.55 V by using this CoP(MoP)-CoMoO3@CN as both cathode and anode for overall water splitting. This promising performance could be due to the high activity of CoP(MoP)-CoMoO3 and the good conductivity of external mesoporous N-carbon shell, which makes the CoP(MoP)-CoMoO3@CN nanowires as a competitive alternative to noble metal based catalysts for water splitting.
关键词： metal phosphides,overall water splitting,synergistic effects,nanowires,N-doped Carbon
更新于2025-09-23 15:22:29
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Highly Enhanced Photocatalytic Water-splitting Activity of Gallium Zinc Oxynitride Derived from Flux-assisted Zn/Ga Layered Double Hydroxides
摘要： The Ga/Zn-oxynitride solid solution [(GaN)1-x(ZnO)x] is one of the promising visible-light harvesting photocatalysts for overall water-splitting. A series of (GaN)1-x(ZnO)x (0.11 ≤ x ≤ 0.33) are synthesized by calcining the carbonate-type Zn/Ga-LDH precursor with and without sodium carbonate flux at 850 oC for 8 - 14 h under a NH3 gas-flow. The solid solutions without flux are determined to be low in crystallinity but plate-like in morphology with preferred orientation could be observed. On the other hand, those with flux turn out to be better in crystallinity, and eventually exhibit significantly higher photocatalytic activity for overall water splitting under visible-light irradiation than those without flux. In addition, the bandgap energies can also be engineered from 2.57 eV to 2.72 eV by changing the synthetic parameter such as nitridation time. It is, therefore, suggested that the present new approach can offer new opportunities for designing the next generation photocatalytic systems.
关键词： Overall water splitting,Photocatalyst,Gallium Zinc Oxynitride,Layered double hydroxides,Flux
更新于2025-09-23 15:21:21
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Enhanced Photoelectrochemical Water Oxidation from CdTe Photoanodes Annealed with CdCl2
摘要： CdTe absorbs sunlight up to 830 nm and has the potential to promote efficient photoelectrochemical (PEC) water splitting. However, most CdTe photoanodes and CdTe photocathodes show positive and negative photocurrent onset potentials for water oxidation and reduction, respectively, and are thus unable to drive PEC water splitting without external applied biases. In this work, we enhanced the activity of a CdTe photoanode having an internal p-n junction during PEC water oxidation by applying a CdCl2 annealing treatment together with surface modifications. The resulting CdTe photoanode generated photocurrents of 1.8 and 5.4 mA cm-2 at 0.6 and 1.2 VRHE, respectively, with a photoanodic current onset potential of 0.22 VRHE under simulated sunlight (AM 1.5G). The CdCl2 annealing increased the grain sizes in this material and lowered the density of grain boundaries, allowing for more efficient charge separation. Consequently, a two-electrode tandem PEC cell comprising a CdTe-based photoanode and photocathode split water without any external bias at a solar-to-hydrogen conversion efficiency of 0.51% at the beginning of the reaction.
关键词： Photoanode,Overall water splitting,Photoelectrochemistry,p-n junction,CdCl2 treatment
更新于2025-09-23 15:21:01