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Photoelectrochemical performances of Fe2O3 nanotube films decorated with cadmium sulfide nanoparticles via photo deposition method
摘要： Hematite is an appropriate compound for photoelectrochemical water splitting. However, passive surface state, high recombination rate of the photo induced electron-hole pairs and poor and slow charge transfer kinetics restrict the performance of hematite. In this work, CdS/Fe2O3NTs samples have been successfully prepared by coating of CdS nanoparticles on the surface of the self-organized Fe2O3NTs via photo deposition technique in order to enhance charge separation and charge transfer kinetics. FESEM (Field Emission Scanning Electron Microscopy), XRD (X-ray diffraction), DRS (Diffraction Reflection Spectroscopy) and XPS (X-ray Photoelectron Spectroscopy) analyses have been used to characterize the CdS/Fe2O3NTs photoelectrodes obtained. CdS/Fe2O3NTs has an intense visible light absorption and displays a red-shift of the band edge in comparison with the bare Fe2O3NTs, according to DRS test. The photocurrent density of Fe2O3NTs increased approximately 5 times upon coating with CdS, as shown by photoelectrochemical measurements, indicating the significant role of the introduction of CdS in the enhancement of photo catalytic activity. CdS/Fe2O3NTs may be promising and effective photoanodes in PEC water splitting given their simple preparation and good performance.
关键词： Cadmium sulfide,Photo deposition,Fe2O3 nanotube,Photoelectrochemical water splitting
更新于2025-09-23 15:21:01
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Combustion synthesis and photoelectrochemical characterization of gallium zinc oxynitrides
摘要： We report a rapid combustion synthesis method for producing band gap tunable gallium zinc oxynitrides, a material of interest for water splitting applications. By varying the ratio of zinc and gallium, we can tune the band gap from 2.22 to 2.8 eV. Furthermore, nitrogen can be incorporated up to nearly 50% via replacement of oxygen without the need for high temperatures or an additional ammonolysis step. X-ray photoelectron spectroscopy (XPS) and EDX analysis suggests a preferential segregation of Zn to the surface of the as-synthesized particles, though the surface Ga/Zn molar ratio in the as-synthesized particles is correlated with the Ga/Zn molar ratio of the precursor materials. Photoelectrochemical measurements show that the oxynitride powders are photoactive under both AM1.5 and visible-only (k . 435 nm) irradiation. Hydrogen and oxygen were both evolved in half-reaction experiments under simulated AM1.5 irradiation without externally applied bias, although addition of an OER catalyst did not enhance the rate of oxygen formation, suggesting that intra- and interparticle recombination are signi?cant.
关键词： water splitting,photoelectrochemical,gallium zinc oxynitrides,band gap tuning,combustion synthesis
更新于2025-09-23 15:21:01
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Ternary Hierarchical Cu <sub/>7</sub> S <sub/>4</sub> /TiO <sub/>2</sub> /CoCr-LDH Heterostructured Nanorod Arrays with Multiphase Reaction Interfaces for More Efficient Photoelectrochemical Water Splitting
摘要： Fabricating hierarchical and highly matched heterostructure with large surface areas and multiple interfaces is an effective approach to enhancing the photoelectrochemical performance. Here, well-aligned hierarchical Cu7S4/TiO2/CoCr-layered double hydroxide (LDH) nanorod arrays are reported, aiming at accelerating charge separation and transfer kinetics. The modifications of Cu7S4 and CoCr-LDH based on TiO2 have endowed the photoanode a surprising enhancement in both ultraviolet light absorption and charge separation efficiency due to highly matched band alignment. The formation of heterojunction is an effective strategy to prevent photocorrosion of Cu7S4 by attaching protective layers on Cu7S4. Moreover, other than the hierarchical morphology with enlarged active surface areas would provide sufficient active sites for the water oxidation processes and pore channels for the gas escaping, owing to the special band alignment of three components, multiple reaction interfaces are produced and involved in the water splitting process, since the photoinduced holes for water oxidation are simultaneously distributed in CoCr-LDH and Cu7S4. As expected, this synergistic effect in this ternary Cu7S4/TiO2/CoCr-LDH heterogeneous photoanode gives rise to a largely enhanced photoconversion efficiency (0.58% at 0.6 V) and photocurrent density (2.04 mA cm?2 at 1.23 V).
关键词： 3D hierarchical nanorod arrays,Cu7S4/TiO2/CoCr-LDH,ternary heterostructure,highly matched band alignment,photoelectrochemical water splitting
更新于2025-09-23 15:21:01
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<i>In situ</i> growth of α-Fe <sub/>2</sub> O <sub/>3</sub> @Co <sub/>3</sub> O <sub/>4</sub> core–shell wormlike nanoarrays for a highly efficient photoelectrochemical water oxidation reaction
摘要： Photoelectrochemical (PEC) water splitting represents a promising strategy to convert solar energy into chemical energy in the form of hydrogen, but its performance is severely limited by the sluggish water oxidation reaction. Herein, for the first time, we report the direct assembly of an ultrathin, uniform, and dense layer of Co3O4 on wormlike nanostructured hematite (WN-α-Fe2O3) to form a large-area and high-density WN-α-Fe2O3@Co3O4 core–shell nanoarray via in situ hydrothermal growth followed by calcination, in which the electrostatic force between WN-α-Fe2O3 and the reactants, pH- and temperature-controlled structures of WN-α-Fe2O3, and ultralow nucleation rate of Co3O4 precursors all play critical roles. The obtained heteronanostructure array shows a photocurrent density of 3.48 mA cm?2, which is 4.05 times higher than that of pristine WN-α-Fe2O3 (0.86 mA cm?2), an onset potential of ～0.62 V, 60 mV lower than that of α-Fe2O3 (～0.68 V), and a photoconversion efficiency of 0.55%, 3.93 times higher than that of WN-α-Fe2O3 (0.14%). This is among the highest performances reported for Fe2O3-based photoanodes for water splitting. It is discovered that the Co3O4 shells can significantly enhance the charge separation, accelerate the charge transport and transfer, and reduce the charge transfer resistance from the photoelectrode to the electrolyte for a fast water oxidation reaction, thereby greatly promoting the PEC water oxidation performance of pristine WN-α-Fe2O3. This work not only creates a novel low-cost and Earth-abundant WN-α-Fe2O3@Co3O4 photoelectrode with superior PEC water oxidation performance and provides scientific insights into the enhancement mechanism, but also offers a general strategy for the in situ growth of water oxidation catalysts on various photoelectrodes with 3-D complex geometries for PEC water splitting.
关键词： α-Fe2O3,water oxidation reaction,Co3O4,Photoelectrochemical water splitting,core–shell nanoarray
更新于2025-09-23 15:19:57
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Strong Lighta??matter Interaction in Au Plasmonic Nanoantennas Coupled with Prussian Blue Catalyst on BiVO4 for Photoelectrochemical Water Splitting
摘要： We establish a facial and large scale compatible fabrication route affording a high performance heterogeneous plasmonic-based photoelectrode for water oxidation that incorporates a CoFe-Prussian blue analog (PBA) structure as the water oxidation catalytic center. For this purpose, an angled deposition of gold (Au) was used to selectively coat the tips of the bismuth vanadate (BiVO4) nanostructures, yielding Au capped BiVO4 (Au-BiVO4). The formation of multiple size/dimension Au capping islands provides strong light-matter interaction at nanoscale dimensions. These plasmonic particles not only enhance light absorption in the bulk BiVO4 (through the excitation of Fabry-Perot (FP) modes) but also contribute to photocurrent generation via the injection of sub-bandgap hot electrons. To substantiate the activity of the photoanodes, the interfacial electron dynamics is significantly improved using a PBA water oxidation catalyst (WOC) resulting in Au-BiVO4/PBA assembly. At 1.23 V vs RHE, the photocurrent value for a bare BiVO4 photoanode was obtained as 190 μA cm?2, while it was boosted to 295 μA cm?2, and 1,800 μA cm?2 for Au-BiVO4, and Au-BiVO4/PBA, respectively. Our results suggest that this simple and facial synthetic approach paves the way for plasmonic-based solar water splitting, in which a variety of common metals and semiconductors can be employed in conjunction with catalyst designs.
关键词： photoelectrochemical water splitting,Prussian blue,plasmonics,hot electron,cyanide chemistry
更新于2025-09-23 15:19:57
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Probing the Advantageous Photosensitization Effect of Metal Nanoclusters over Plasmonic Metal Nanocrystals in Photoelectrochemical Water Splitting
摘要： Atomically precise metal nanoclusters (NCs)-based photocatalytic systems have garnered enormous attention owing to the fascinating merits including unique physicochemical properties, quantum confinement effect and photosensitization effect, which are distinct from conventional metal nanocrystals (NYs). Nevertheless, systematic comparison between electrons photoexcited from metal NCs and hot electrons from surface plasmonic resonance (SPR) effect of metal NYs in boosting photoelectrochemical water splitting reaction remains blank. Here, we report the strict and comprehensive comparison on the capability of electrons photoexcited from glutathione-capped gold nanoclusters (Aux@GSH) and hot electrons from plasmonic excitation of gold nanoparticles (Au NYs) self-transformed from Aux@GSH to trigger the PEC water splitting reaction under visible light irradiation. The results indicate photoelectrons of Aux NCs trigger more efficient charge transport rate than hot electrons of plasmonic Au NYs in terms of light harvesting and conversion efficiency under the identical conditions. Moreover, charge transfer characteristics in Aux NCs and Au NYs-based PEC systems were established. This work would reinforce our deep understanding on these two pivotal sectors of metal nanomaterials for solar energy conversion.
关键词： photosensitization effect,plasmonic metal nanocrystals,charge transfer,photoelectrochemical water splitting,metal nanoclusters
更新于2025-09-23 15:19:57
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Enhanced photoelectrochemical performance of plasmonic Ag nanoparticles grafted ternary Ag/PaNi/NaNbO3 nanocomposite photoanode for photoelectrochemical water splitting
摘要： In this work, we have successfully synthesized silver nanoparticles (Ag-NPs) decorated binary PaNi/NBO nanocomposite by facile chemisorption route and demonstrated enhanced photoelectrochemical (PEC) water splitting activity. The ternary Ag/PaNi/NBO nanocomposite photoanode exhibits ~5 fold higher current density than pristine NaNbO3 nanofibers (NBO-NFs). The ternary Ag/PaNi/NBO photoanode exhibits a current density of 5.93 mA/cm2 at 0.9 V with respect to Ag/AgCl, whereas the pristine NBO-NFs photoanode exhibits only 0.85 mA/cm2 at 0.9 V. The improved performance is correlated to the high surface area, formation of the type-II heterojunction among PaNi and NBO-NFs and the introduction of the plasmonic behaviour of Ag-NPs as it expands the absorption of the visible part of the solar spectrum, which together decreases the recombination of charges with strong redox capability. Furthermore, the ternary Ag/PaNi/NBO photoanode showed lower charge transfer resistance (Rct) in the EIS measurements and improved incident photon to current efficiency (IPCE) of ~31.3% which is ~23% higher to the IPCE of bare NBO-NFs photoanode. Thus, these results suggest that the ternary Ag/PaNi/NBO nanocomposite is a promising material for PEC activity and wide practical applications.
关键词： Water Splitting,Silver nanoparticle,PaNi,NaNbO3,Ag/PaNi/NBO
更新于2025-09-23 15:19:57
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Metal-Reduced WO3a??x Electrodes with Tunable Plasmonic Resonance for Enhanced Photoelectrochemical Water Splitting
摘要： Photoelectrochemical (PEC) water splitting is one of the most promising green technologies for producing renewable clean hydrogen energy. Developing plasmonic semiconductors with tunable plasmonic resonance to visible light has drawn increasing attention in view of utilizing abundant low-energy photons for solar-to-chemical conversion. Herein, we demonstrate for the first time that the WO3 electrode can be partly reduced by various metal foils in acid solution, showing strong localized surface plasmon resonance (LSPR) in the visible-to-near-infrared (Vis–NIR) region. The LSPR can be precisely tuned by using metal foils with different standard electrode potentials for different reaction times, and the LSPR peak position strongly depends on the concentration of W5+ in the WO3?x electrodes. A photocurrent density of 0.79 mA·cm?2 at 1.23 VRHE, which is twice that of pristine one, is obtained over an optimally reduced WO3?x electrode. The enhanced PEC water splitting performance is ascribed to the increased light absorption, conductivity and charge carrier concentration.
关键词： photoelectrochemical water splitting,semiconductor,plasmonic resonance,metal foil,tungsten oxide
更新于2025-09-23 15:19:57
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High-Performance Silicon Photoanode Enabled by Oxygen Vacancy Modulation on NiOOH Electrocatalyst for Water Oxidation
摘要： Silicon (Si) is an attractive photoanode material for photoelectrochemical (PEC) water splitting. However, Si photoanode is highly challenging due to its poor stability and catalytic inactivity toward oxygen evolution reaction (OER). Integration of highly active electrocatalysts with Si photoanodes has been considered as an effective strategy to improve OER performance through accelerates reaction kinetics and inhibits Si photocorrosion. In this work, ultra-small NiFe nanoparticles are deposited onto n-Si/Ni/NiOOH surface to improve the activity and stability of Si photoanode by engineering the electrocatalyst and Si interface. Ultra-small NiFe can introduce oxygen vacancies via modulating the local electronic structure of Ni hosts in NiOOH electrocatalyst for fast charge separation and transfer. Besides, NiFe nanoparticles also can serve as co-catalyst exposure more active sites and as protection layer prevents Si photocorrosion. The as-prepared n-Si/Ni/NiOOH/NiFe photoanode exhibits excellent OER activity with an onset potential of 1.0 V versus reversible hydrogen electrode (RHE) and a photocurrent density of ～25.2 mA cm-2 at 1.23 V versus RHE. This work provides a promising approach to design high-performance Si photoanodes by surface electrocatalyst engineering.
关键词： photoelectrochemical water splitting,oxygen vacancies,OER activity,NiFe nanoparticles,Silicon photoanode
更新于2025-09-23 15:19:57
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Pure CuBi <sub/>2</sub> O <sub/>4</sub> Photoelectrodes with Increased Stability by Rapid Thermal Processing of Bi <sub/>2</sub> O <sub/>3</sub> /CuO Grown by Pulsed Laser Deposition
摘要： A new method for enhancing the charge separation and photo-electrochemical stability of CuBi2O4 photoelectrodes by sequentially depositing Bi2O3 and CuO layers on fluorine-doped tin oxide substrates with pulsed laser deposition (PLD), followed by rapid thermal processing (RTP), resulting in phase-pure, highly crystalline films after 10 min at 650 °C, is reported. Conventional furnace annealing of similar films for 72 h at 500 °C do not result in phase-pure CuBi2O4. The combined PLD and RTP approach allow excellent control of the Bi:Cu stoichiometry and results in photoelectrodes with superior electronic properties compared to photoelectrodes fabricated through spray pyrolysis. The low photocurrents of the CuBi2O4 photocathodes fabricated through PLD/RTP in this study are primarily attributed to their low specific surface area, lack of CuO impurities, and limited, slow charge transport in the undoped films. Bare (without protection layers) CuBi2O4 photoelectrodes made with PLD/RTP shows a photocurrent decrease of only 26% after 5 h, which represents the highest stability reported to date for this material. The PLD/RTP fabrication approach offers new possibilities of fabricating complex metal oxides photoelectrodes with a high degree of crystallinity and good electronic properties at higher temperatures than the thermal stability of glass-based transparent conductive substrates would allow.
关键词： CuBi2O4,solar water splitting,rapid thermal processing,ternary oxides,pulsed laser deposition
更新于2025-09-23 15:19:57