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Synthesis of Porous ZnO Nanosheets and Carbon Nanotube Hybrids as Efficient Photocatalysts via Pulsed Laser Ablation
摘要： Zinc oxide (ZnO) has attractive photocatalytic properties. However, the high recombination rate of the photo-excited charge carriers on this material often restricts application. Here, we report that hybridization of one dimensional (1D) carbon nanotubes (CNT) on two dimensional (2D) porous ZnO nanosheets (NS) can be a promising strategy to overcome some of the challenges of ZnO. Specifically, a pulsed laser ablation technique was utilized to hybridize 1D CNT with 2D porous ZnO NS in environmentally friendly as well as super-economic (short time, less than 10 min) conditions. The synthesized ZnO NS-CNT hybrids show a significantly enhanced photocatalytic activity for water splitting relative to their counterpart ZnO NS.
关键词： pulsed laser ablation,water splitting,carbon nanotube,photocatalyst,zinc oxide,nanocomposites
更新于2025-09-16 10:30:52
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Electronic doping-enabled transition from n- to p-type conductivity over Au@CdS core–shell nanocrystals toward unassisted photoelectrochemical water splitting
摘要： Here we show a novel strategy for tailoring the synergistic electrical properties of metal@semiconductor hybrid nanocrystals (HNCs) based on cation exchange-enabled electronic doping. As a demonstration, the conductive nature of Au@CdS core–shell HNCs was changed from n- to p-type by introducing Cu dopants into the CdS shell. The dependence of the conductivity type on the dopant concentration in the HNCs is disclosed by combined photoelectrochemical (PEC) studies. Moreover, a tandem PEC cell consisting of an undoped Au@CdS photoanode and a Cu-doped Au@CdS photocathode respectively modified with cocatalysts is fabricated, which displayed stable H2 and O2 evolution in unassisted PEC overall water splitting.
关键词： photoelectrochemical water splitting,electronic doping,cation exchange,metal@semiconductor hybrid nanocrystals
更新于2025-09-16 10:30:52
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Facile synthesis and characterization of V2O5 nanobelt bundles containing plasmonic Ag for photoelectrochemical water splitting under visible light irradiation
摘要： V2O5 nanobelt bundle (NBB) photoanodes were synthesized from commercial V2O5 powder via a facile, room-temperature aqueous solution technique. The V2O5 NBBs were several micrometers long and 15–25 nm wide, with an orthorhombic V2O5 structure, a crystallite size of 63 nm, and an optical bandgap of 2.19 eV. The V2O5 NBBs containing plasmonic Ag showed signi?cantly lower charge transfer resistance than the pure V2O5 NBBs. The charge transfer resistance was further reduced to 21.02 Ω by adding 10% methanol to the 0.1 M KOH electrolyte as a hole scavenger. The water-splitting activity of the V2O5 and V2O5/Ag photoanodes was tested in 0.1 M KOH; a very low photocurrent density of 0.5 μA/cm2 was observed under visible light illumination. The low photocurrent was ascribed to a build-up of photogenerated holes at the photoelectrode/aqueous electrolyte. The addition of methanol drastically increased the photocurrent of the V2O5 NBB photoelectrode. A maximum photocurrent density of 0.2 mA/cm2 was achieved for up to 230 s under light illumination for the V2O5 NBBs containing plasmonic Ag in KOH and methanol, which was 400 times higher than that of the photoanode without a hole scavenger.
关键词： Aqueous electrolyte,Nanowires,Hole scavenger,Ag plasmonic,Water splitting activity
更新于2025-09-16 10:30:52
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Copper Tungstate (CuWO4) Nanoflakes Coupled with Cobalt Phosphate (Co-Pi) for Effective Photoelectrochemical Water Splitting
摘要： Photoelectrochemical (PEC) water splitting provides us a green way to convert and utilize solar energy. In this work, Co-Pi was electrochemically deposited onto CuWO4 nanoflakes (NFs) via a cyclic voltammetry (CV) method to enhance the photocatalytic performance of CuWO4 toward PEC water splitting. The results demonstrated that the photocurrent density as well as the charge-transfer efficiency was improved within the entire potential range. Besides, the CuWO4/Co-Pi exhibited an enhanced stability over the bare CuWO4 in the phosphate buffer solution (pH 7) and an extremely high Faradaic efficiency (ca. 96%). Our work reveals that combination of CuWO4 with Co-Pi is a feasible way to further enhance the performance of CuWO4 photoanode toward PEC OER.
关键词： Photoelectrochemical water splitting,oxygen evolution reaction,copper tungstate,electrochemical cocatalyst,cobalt phosphate
更新于2025-09-16 10:30:52
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In-situ implantation of plasmonic Ag into metal-organic frameworks for constructing efficient Ag/NH2-MIL-125/TiO2 photoanode
摘要： Realizing a highly efficient catalytic activity for photoelectrochemical (PEC) water splitting has been becoming a key challenge for fabricating TiO2 photoanode, due to its weak light-response ability and poor electrical conductivity. For the first time, we prepared the TiO2 nanorods decorated with NH2-MIL-125 film, and subsequently in-situ implanted Ag nanoparticles (Ag NPs) into NH2-MIL-125 film by mild reduction process with the help of amine group. The synergistic effect between NH2-MIL-125 and Ag NPs is aimed at efficiently improving light-response and the overall conductivity of photoanode. The PEC performance of as-prepared Ag/NH2-MIL-125/TiO2 hybrid-photoanode has been systemically investigated. The photocurrent density of optimal Ag/NH2-MIL-125/TiO2 has reached 1.06 mA/cm2 at 1.23 V (vs. RHE) under illumination (100 mW/cm2), which is almost 4.42 times higher than that of pristine TiO2. The incident photon-to-electron conversion efficiency (IPCE) value of Ag/NH2-MIL-125/TiO2 has been increased to 51.0 % at 390 nm. Furthermore, the desirable charge injection (ηinjection) of 96.4% and charge separation (ηseparation) efficiency of 33.1% have been achieved. The in-situ introduction of Ag NPs into NH2-MIL-125/TiO2 heterostructure provides a novel model for understanding the synergistic effect between metal and MOF over PEC water splitting.
关键词： NH2-MIL-125,hybrid-photoanode,photoelectrochemical water splitting,Ag nanoparticles
更新于2025-09-16 10:30:52
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Simultaneously efficient light absorption and charge transport of CdS/TiO2 nanotube array toward improved photoelectrochemical performance
摘要： CdS has been widely used to modify TiO2-based photoanodes for photoelectrochemical (PEC) water splitting. Due to the poor interface contact between chalcogenides and oxides, however, such CdS modified TiO2 materials usually exhibit inefficient separation and transport of charges, leading to an unsatisfactory efficiency during the PEC water splitting process. Addressing this issue, we herein report a CdS/TiO2 nanotube array (CdS/TNA) photoanode that was fabricated through a successive ion layer absorption and reaction (SILAR) method with an additional subsequent annealing. This post-annealing process is essential to enhance the interface contact between the CdS and the TNAs, resulting in an accelerated transfer of photogenerated electrons from the CdS to the TNAs. In addition, the post-annealing also improves the light absorption capability of the CdS/TNA photoanode. The simultaneous enhancement of charge transport and light absorption provided by the post-annealing is essential for improving the PEC performance of the CdS/TNA photoanode. The CdS/TNA photoanode obtained by this strategy exhibits a much enhanced PEC performance in water splitting, and its photocurrent density and solar-to-hydrogen conversion efficiency could reach 4.56 mA cm?2 at 1.23 V vs. reversible hydrogen electrode and 5.61%, respectively. This simple but effective route can provide a general strategy for obtaining high-performance oxide-based photoelectrodes.
关键词： Photoelectrochemical water splitting,Nanotube arrays,Titanium dioxide,Cadmium sulfide
更新于2025-09-12 10:27:22
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Strongly Coupled Amorphous Porous NbO <sub/>x</sub> (OH) <sub/>y</sub> /g‐C <sub/>3</sub> N <sub/>4</sub> Heterostructure Composite for Efficient Photocatalytic Hydrogen Evolution
摘要： Heterostructure composites are promising materials in photocatalytic hydrogen evolution due to their advantage on promoting photogenerated carrier separation efficiently. However, the weak interfacial interaction can block electron transfer and complicate synthesis methods restrict the practical application of catalysts. Here, we report an interfacial enhanced amorphous porous NbOx(OH)y/g-C3N4 heterostructure composite through a spontaneous coupling process. It was characterized by XRD, TEM, FT-IR, XPS, NH3-TPD and CO2-TPD, etc., which demonstrated that NbOx(OH)y possess amorphous porous structures with high specific surface area (205 m2/g) and plenty of acidic sites (418 μmol/g) as well as basic sites (184 μmol/g) contributed from uncoordinated Nb and -OH. These acidic and basic sites electrostatically attract -NHx and C-OH on the surface of g-C3N4 to form hydrogen bonds (Nb-O-H???NH2, Nb-O???H-O-C), showing a strong electron interaction between NbOx(OH)y and g-C3N4. When tested as a photocatalyst for water splitting under visible light, the optimal NbOx(OH)y/CN-0.05 heterostructure composite exhibits a hydrogen evolution rate of 53 μmol/g/h, which is about 14 times higher than that of g-C3N4 (3.8 μmol/g/h) and is even superior than P25 (16 μmol/g/h). These present findings lay a foundation for the synthesis of strongly interacting heterogeneous composites.
关键词： heterojunction,water splitting,amorphous niobium oxide,photocatalysis,g-C3N4
更新于2025-09-12 10:27:22
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Co(OH)2/BiVO4 photoanode in tandem with a carbon-based perovskite solar cell for solar-driven overall water splitting
摘要： BiVO4 as a promising candidate photoanode material for PEC water splitting has been paid much attention due to its low cost, nontoxicity, high stability and narrow band gap energy of 2.4 eV. However, owing to its short carrier diffusion length and poor charge separation consequence the achieved efficiency of the BiVO4 photoanode is still limited. Herein, we addressed this issue by loading Co(OH)2 onto as-prepared BiVO4 to fabricate Co(OH)2/BiVO4 heterojunction photoanode via a simple solution impregnation method, in which Co(OH)2 as a modifier can increase interface charge separation efficiency from 44% of BiVO4 to 92% of Co(OH)2/BiVO4. As a result, the water-splitting photocurrent density was significantly enhanced from 1.57 mA/cm2 of BiVO4 to 4.52 mA/cm2 of Co(OH)2/BiVO4 at 1.23 V vs. RHE under 1-sun illumination. Further, the Co(OH)2/BiVO4 photoanode was assembled in tandem with a single sealed carbon-based PSC, and the resulting PV-PEC device showed a high STH efficiency of 4.6% and decent stability. The produced H2 and O2 gases were determined as ~68 μmol/cm2/h and ~34 μmol/cm2/h, respectively, corresponding to the 2:1 ratio of water splitting reaction with a faradaic efficiency of ~98%.
关键词： heterojunction photoanode,water splitting,tandem device,Co(OH)2/BiVO4
更新于2025-09-12 10:27:22
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The effects of the oxygen content on the photoelectrochemical properties of LaFeO3 perovskite thin films obtained by pulsed laser deposition
摘要： The physical properties of perovskite oxides are strongly influenced by their stoichiometry and one of the key features of these materials is the tunability of their functionality by controlling the interplay between the compositional and structural properties. Here, the effects on the photoelectrochemical (PEC) water splitting properties of ferroelectric LaFeO3 thin films obtained at different oxygen partial pressures during growth are reported in conjunction with the morphological, optical and structural features. The LaFeO3 thin films have been deposited by pulsed laser deposition on Nb:SrTiO3 substrates. The strong dependence of the photocurrent values Jphoto on the growth conditions is revealed by the photoelectrochemical measurements. Strong variations of the lateral coherence lengths L‖ of LaFeO3/Nb:SrTiO3 with the oxygen partial pressure values are noticed from the X-ray diffraction (XRD) analysis. All the films are heteroepitaxial with small tensile strain levels detected in the crystalline structure, but only for a narrow interval of oxygen partial pressures the LFO/STON thin films show high quality crystalline structure with large lateral coherence length L‖ and photoelectrochemical currents.
关键词： oxygen partial pressure,perovskite oxides,photoelectrochemical,pulsed laser deposition,water splitting
更新于2025-09-12 10:27:22
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Enhanced photoelectrochemical performance of NaNbO3 nanofibers photoanode coupled with visible-light active g-C3N4 nanosheets for water splitting
摘要： Sodium niobate nanofibers (NaNbO3-NF) have been synthesized by hydrothermal technique and further coupled with visible light responsive graphitic carbon nitride (g-C3N4) nanosheets in the different concentration ratio of 2:1 (2-CN), 4:1 (4-CN) and 8:1 (8-CN). A significant improvement in the photoelectrochemical (PEC) performance of g-C3N4/NaNbO3-NF (4-CN) nanostructured photoanode as compared to bare NaNbO3 photoanode is observed. A current density of 12.55 mA cm?2 at 1 V with respect to Ag/AgCl reference electrode is achieved for g-C3N4/NaNbO3-NF (4-CN) photoanode which is ~3 times higher than the NaNbO3-NF photoanode. Also, as compared to NaNbO3-NF, g-C3N4/NaNbO3-NF (4-CN) nanocomposite photoanode showed ~3 times improvement in the incident photon-to-current conversion efficiency. The improvement in the PEC performance of visible light active g-C3N4/NaNbO3-NF (4-CN) nanocomposite is attributed to the improved photoresponse of NaNbO3-NF due to the coupling of g-C3N4 and formation of type-II heterojunction between them leading to the enhanced separation of the photogenerated charge carriers. A possible reaction mechanism for the improved photoelectrochemical water splitting performance has been proposed for g-C3N4/NaNbO3-NF (4-CN) photoanode.
关键词： Photoelectrode,Nanocomposite,Heterojunction,g-C3N4/NaNbO3-NF,PEC Water Splitting
更新于2025-09-12 10:27:22