- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Comparative Study of the Structure, Composition, and Electrocatalytic Performance of Hydrogen Evolution in MoSx~2+?′/Mo and MoSx~3+?′ Films Obtained by Pulsed Laser Deposition
摘要： Systematic and in-depth studies of the structure, composition, and efficiency of hydrogen evolution reactions (HERs) on MoSx films, obtained by means of on- and off-axis pulsed laser deposition (PLD) from a MoS2 target, have been performed. The use of on-axis PLD (a standard configuration of PLD) in a buffer of Ar gas, with an optimal pressure, has allowed for the formation of porous hybrid films that consist of Mo particles which support a thin MoSx~2+δ (δ of ~0.7) film. The HER performance of MoSx~2+δ/Mo films increases with increased loading and reaches the highest value at a loading of ~240 μg/cm2. For off-axis PLD, the substrate was located along the axis of expansion of the laser plume and the film was formed via the deposition of the atomic component of the plume, which was scattered on Ar molecules. This made it possible to obtain homogeneous MoSx~3+δ (δ~0.8–1.1) films. The HER performances of these films reached saturation at a loading value of ~163 μg/cm2. The MoSx~3+δ films possessed higher catalytic activities in terms of the turnover frequency of their HERs. However, to achieve the current density of 10 mA/cm2, the lowest over voltages were ?162 mV and ?150 mV for the films obtained by off- and on-axis PLD, respectively. Measurements of electrochemical characteristics indicated that the differences in the achievable HER performances of these films could be caused by their unique morphological properties.
关键词： nanocatalysts,buffer gas,pulsed laser deposition,transition metal chalcogenides,hydrogen evolution reaction
更新于2025-09-19 17:13:59
-
Tandem Si Micropillar Array Photocathodes with Conformal Copper Oxide and a Protection Layer by Pulsed Laser Deposition
摘要： This work demonstrates the influence of high-quality protection layers on Si-Cu2O micropillar arrays created by pulsed laser deposition (PLD), with the goal to overcome photodegradation and achieve long-term operation during photoelectrochemical (PEC) water splitting. Sequentially, we assessed planar and micropillar device designs with various design parameters and their influence on PEC hydrogen evolution reaction. On the planar device substrates, a Cu2O film thickness of 600 nm and a Cu2O/CuO heterojunction layer with a 5:1 thickness ratio between Cu2O to CuO were found to be optimal. The planar Si/Cu2O/CuO heterostructure showed a higher PV performance (Jsc = 20 mA/cm2) compared to the planar Si/Cu2O device, but micropillar devices did not show this improvement. Multifunctional overlayers of ZnO (25 nm) and TiO2 (100 nm) were employed by PLD on Si/Cu2O planar and micropillar arrays to provide a hole-selective passivation layer that acts against photocorrosion. A micropillar Si/ITO-Au/Cu2O/ZnO/TiO2/Pt stack was compared with a planar device. Under optimized conditions, the Si/Cu2O photocathode with Pt as a HER catalyst displayed a photocurrent of 7.5 mA cm?2 at 0 V vs RHE and an onset potential of 0.85 V vs RHE, with a stable operation for 75 h.
关键词： tandem photocathode,copper oxide,Si micropillar array,hydrogen evolution reaction,pulse laser deposition
更新于2025-09-19 17:13:59
-
Direct growth of high-content 1T phase MoS2 film by pulsed laser deposition for hydrogen evolution reaction
摘要： The modified MoS2-based material, with a higher conductivity and rich active sites, is promising one of a variety of nonprecious-metal electrocatalysts for hydrogen evolution reaction (HER). Here, the bulk MoS2 is exfoliated to form small-size MoS2 clusters by pulse laser, which are diluted in solid sulfur and further to form porous film. The 1T phase MoS2 ratio in the prepared film was modulated by adding the different content of sulfur into MoS2 target. Besides, this addition also has an effect on the pore structure of films. Finally, the obtained high-content 1T phase MoS2 film provides the highly metallic conductivity and more active sites, which results in the more enhanced HER catalytic activity with a lower Tafel slope of 38 mV dec-1, a smaller overpotential of 151 mV at 10 mA cm-2, compared with the pure MoS2 film.
关键词： pulsed laser deposition,sulfur addition,1T phase MoS2,Hydrogen evolution reaction
更新于2025-09-19 17:13:59
-
Plasmonic Au nanoparticle-decorated Bi2Se3 nanoflowers with outstanding electrocatalytic performance for hydrogen evolution
摘要： Hydrogen production from water splitting through electrocatalytic or photoelectrochemical route shows great potential for renewable energy conversion. Herein, the plasmon-enhanced photoelectrical nanocatalysts (NCs) have been successfully developed by Au nanoparticle-decorated Bi2Se3 nanoflowers (Au@Bi2Se3 NFs) as catalysts for hydrogen evolution reaction (HER), leading to a more than 3-fold increase of current under excitation of Au localized surface plasmon resonance (LSPR) and affording a markedly decreased overpotential of 375 mV at a current density of 10 mA cm?2. The HER enhancement can be largely attributed to effective electron-charge separation and the increase of carrier density in Bi2Se3 induced by the injection of hot electrons of Au nanoparticles. Meanwhile, Bi2Se3 nanoflowers (NFs), a kind of topological insulators, possess gapless edges on boundary and show metallic character on surface, providing a path for the flow of electrons in the electrocatalytic system. This study opens up a new avenue towards the design of higher energy conversion catalytic water splitting systems with the assistance of light energy, which could increase of HER catalysis efficiency by plasmonic excitation.
关键词： Hydrogen evolution reaction,Plasmonic,Bi2Se3,Au
更新于2025-09-16 10:30:52
-
Pulsed Laser Deposition of Nanostructured MoS3/np-Mo//WO3?y Hybrid Catalyst for Enhanced (Photo) Electrochemical Hydrogen Evolution
摘要： Pulsed laser ablation of MoS2 and WO3 targets at appropriate pressures of background gas (Ar, air) were used for the preparation of new hybrid nanostructured catalytic ?lms for hydrogen production in an acid solution. The ?lms consisted of a nanostructured WO3?y underlayer that was covered with composite MoS3/np-Mo nanocatalyst. The use of dry air with pressures of 40 and 80 Pa allowed the formation of porous WO3?y ?lms with cauli?ower- and web-like morphology, respectively. The ablation of the MoS2 target in Ar gas at a pressure of 16 Pa resulted in the formation of amorphous MoS3 ?lms and spherical Mo nanoparticles. The hybrid MoS3/np-Mo//WO3?y ?lms deposited on transparent conducting substrates possessed the enhanced (photo)electrocatalytic performance in comparison with that of any pristine one (MoS3/np-Mo or WO3?y ?lms) with the same loading. Modeling by the kinetic Monte Carlo method indicated that the change in morphology of the deposited WO3?y ?lms could be caused by the transition of ballistic deposition to di?usion limited aggregation of structural units (atoms/clusters) under background gas pressure growth. The factors and mechanisms contributing to the enhancement of the electrocatalytic activity of hybrid nanostructured ?lms and facilitating the e?ective photo-activation of hydrogen evolution in these ?lms are considered.
关键词： pulsed laser deposition,tungsten oxides,transition metal chalcogenides,nanocatalysts,hydrogen evolution reaction,background gas
更新于2025-09-16 10:30:52
-
Electric field-assisted synthesis of Pt, carbon quantum dots-coloaded graphene hybrid for hydrogen evolution reaction
摘要： A simple method for preparation of Pt, CQDs-coloaded graphene composite for hydrogen evolution reaction (HER) is established by electrolysis-solvothermal process. Graphene is obtained by electrochemical exfoliation of graphite in cathode, while carbon quantum dots (CQDs) and Pt nanoparticles (NPs) are in-situ generated in the electrolyte simultaneously. CQDs are evolved from propylene carbonate solvent and Pt NPs are derived from reduction of Pt intermediate species generated from anodic dissolution of Pt counter electrode during electrolysis process. Then Pt NPs and CQDs are well dispersed on graphene at subsequent solvothermal process. Work voltage and electrolyte type as the key electrolysis conditions are applied to control the concentration of CQDs and Pt NPs, which decides electrochemically active surface area and HER activity of obtained catalysts. Significantly, the obtained superior catalyst with trace amount of Pt (0.145 wt%), shows markedly enhanced catalytic HER activity with mass activity of 37.5 A mg?1 at ?50 mV in acidic solution, 68.2 times more active than Pt/C. This study provides a universal and promising methodology for synthesizing Pt, CQDs coloaded hybrid with the assistance of electric field as cost-effective catalysts for fuel cells.
关键词： Pt nanoparticles,Carbon quantum dots,Graphene,Hydrogen evolution reaction
更新于2025-09-16 10:30:52
-
Charge Transfer Engineering via Multiple Heteroatom Doping in Dual Carbon-Coupled Cobalt Phosphides for Highly Efficient Overall Water Splitting
摘要： The exploration of non-noble-metal bifunctional electrocatalysts with high activity and stability for overall water splitting is crucial, but remains challenging for hydrogen fuel production. Herein, tuning of the charge transfer ability and catalytic performance of zeolitic imidazolate framework-derived porous carbon/reduced graphene oxide-coupled CoP composites (CoP@C@rGO) was achieved by incorporating multiple heteroatoms. The combined experimental investigation and density functional theory calculations revealed that the electronic interaction within the composites caused by B, N, and S tri-doped heteroatoms effectively induced interfacial charge transfer, which improved the active site accessibility and reduced the energy barriers of the evolution reaction; water splitting intermediates. From the synergetic effects of the components, the overall water splitting electrolyzer assembled using the newly prepared B,N,S-CoP@C@rGO catalyst required only 1.50 V to drive a current density of 10 mA cm–2, which is superior to the commercial Pt/C and IrO2/C couple (1.56 V).
关键词： hydrogen evolution reaction,oxygen evolution reaction,multiple doping,overall water splitting,charge transfer
更新于2025-09-12 10:27:22
-
MoSx quantum dots modified black silicon for high efficient photoelectrochemical hydrogen evolution
摘要： Nanostructured black silicon (bSi) is widely used for solar water splitting application due to the excellent light-harvesting properties and large surface area-to-volume ratio that favors photoelectrochemical reactions. However, bSi suffers from low catalytic activity, owing to its poor charge transfer kinetics during hydrogen evolution process. In this work, we developed a novel photoelectrode by incorporating molybdenum sulfide (MoSx) quantum dots on the surface of black silicon. The synergetic effect of MoSx and bSi significantly enhance the activity for hydrogen evolution reaction. An onset potential of 0.255 VRHE, a high short-circuit photocurrent density (Jsc) of 12.2 mA·cm-2, and a hydrogen evolution rate of 226.5 μmol·h-1·cm-2 have been achieved.
关键词： photocathode,Black silicon,MoSx quantum dots,hydrogen evolution reaction
更新于2025-09-12 10:27:22
-
Controlled Micro/Nanodome Formation in Proton‐Irradiated Bulk Transition‐Metal Dichalcogenides
摘要： At the few-atom-thick limit, transition-metal dichalcogenides (TMDs) exhibit strongly interconnected structural and optoelectronic properties. The possibility to tailor the latter by controlling the former is expected to have a great impact on applied and fundamental research. As shown here, proton irradiation deeply affects the surface morphology of bulk TMD crystals. Protons penetrate the top layer, resulting in the production and progressive accumulation of molecular hydrogen in the first interlayer region. This leads to the blistering of one-monolayer thick domes, which stud the crystal surface and locally turn the dark bulk material into an efficient light emitter. The domes are stable (>2-year lifetime) and robust, and host strong, complex strain fields. Lithographic techniques provide a means to engineer the formation process so that the domes can be produced with well-ordered positions and sizes tunable from the nanometer to the micrometer scale, with important prospects for so far unattainable applications.
关键词： transition-metal dichalcogenides,hydrogen evolution reaction,strain,photoluminescence,2D materials,Raman
更新于2025-09-11 14:15:04
-
Fabricating Cu, Cu<sub>2</sub>O and Hybrid Cu-Cu<sub>2</sub>O nanoparticles in carbon matrix and exploring catalytic activity of oxygen and hydrogen evolution and green A<sup>3</sup>-coupling reaction
摘要： Hybrid Cu-Cu2O as well as Cu and Cu2O@C nanoparticles (NPs) encapsulated by carbon matrix have been synthesized and bifunctional electrocatalytic activity (OER and HER) and A3 coupling (three components reaction) were explored. Powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HR-TEM) studies were performed to analyse structure, chemical state, and size of the nanocatalysts. Hybrid Cu-Cu2O@C materials exhibited stronger electrocatalytic activity compared to pure phases whereas pure Cu and Cu2O@C NPs displayed better catalytic activity for A3 coupling reaction. Oxygen and hydrogen evolution reaction (OER and HER) showed enhanced current response (57.8 mA/cm2 and -172 mA/cm2) for hybrid NPs with higher Cu2O ratio. Thus, the present work investigated the role of Cu and Cu2O ratio for fabricating earth abundant cost effective nanocatalysts for OER, HER, and organic chemical transformation.
关键词： Water splitting,A3 coupling,Oxygen evolution reaction,Hydrogen evolution reaction,Cu-Cu2O nanoparticles,Electrocatalyst
更新于2025-09-10 09:29:36