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Synthesis of Cu2O/Carbon film/NiCoB-GO Heterostructure Photocathode for Efficient Photoelectrochemical Water Splitting
摘要： Photoelectrochemical (PEC) water splitting offers a promising way to convert solar energy to chemical energy. The electron transfer rate and surface-catalyzed ability toward hydrogen evolution reaction (HER) play the key roles in the efficiency of PEC water splitting. In this work, a Cu2O/Carbon film/NiCoB-GO heterostructure photocathode is fabricated. Among them, thickness-controllable carbon film served as the electron transport and protective layer with favourable optical property, NiCoB-GO amorphous catalyst displays the efficient performance towards HER in neutral condition. The optimized photocathode shows the PEC-HER performance with a photocurrent density of -2.9 mA/cm2 at 0 V vs. RHE, and it also presents better stability than bare Cu2O. This work provides a novel heterostructure photocathode for promoting solar-driven PEC water splitting efficiently.
关键词： Femtosecond transient absorption spectroscopy,Photoelectrochemical water splitting,Electron transport path,Carbon film,Amorphous catalyst
更新于2025-09-19 17:15:36
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Niobium incorporated WO3 nanotriangles: Band edge insights and improved photoelectrochemical water splitting activity
摘要： In this work, a facile hydrothermal method is proposed to fabricate Nb-doped WO3 nanotriangle thin films, and their band edge properties and photoelectrochemical water splitting activity were explored. The process of doping and thin film formation was simultaneously achieved in a single step hydrothermal condensation of peroxopolytungstic acid solution containing Nb precursor. The crystallographic study reveals that doping of Nb into WO3 lattice obstructs the reconstructive transformation of orthorhombic WO3·0.33H2O during annealing consequently producing hexagonal phase instead of the monoclinic phase. The insertion of Nb causes the increase in band gap and induces oxygen vacancies in WO3. Uniform distribution of Nb in WO3 was observed containing majorly Nb5+ valence and a small amount of Nb4+ state. PEC characterization showed the increase in photocurrent, (at AM 1.5G illumination) incident photon to current and photoconversion efficiency values of WO3 upon Nb doping. Band edge analysis revealed that both conduction and valence band edge of WO3 show downward shift towards higher potential vs. RHE whereas the Fermi level show upward shift as a result of Nb doping.
关键词： Band edge,Niobium,Reconstructive transformation,Tungsten oxide,Photoelectrochemical water splitting
更新于2025-09-19 17:15:36
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Construction of two dimensional Sr2Ta2O7/S-doped g-C3N4 nanocomposites with Pt cocatalyst for enhanced visible light photocatalytic performance
摘要： Visible light-driven photocatalytic hydrogen production has been deemed a potential means to solve the increasingly serious energy shortage problem. Herein, two dimensional (2D) Sr2Ta2O7/S-doped g-C3N4 nanocomposites that applied in photocatalytic water reduction were fabricated through thermal condensation of thiourea with hydrothermal-prepared Sr2Ta2O7. The resulted Sr2Ta2O7/S-doped g-C3N4 nanocomposite exhibited enhanced hydrogen evolution rate (11.36 μmol g?1 h?1) under visible light irradiation, which is about 3.5 times higher than that of pure S-doped g-C3N4. In light of the UV–vis diffuse reflectance spectroscopy, Mott-Schottky curve and photoluminescence spectra, the enhanced photocatalytic performance could be mainly attributed to the conduction band difference between Sr2Ta2O7 and S-doped g-C3N4. In addition, transient photoluminescence spectra, electrochemical impedance spectra and photocurrent responses proved that the presence of Pt cocatalyst also plays an important role in facilitates the transport of photoexcited electron-hole pairs, subsequently promoting the photocatalytic performance.
关键词： Sr2Ta2O7,Nanocomposite,g-C3N4,Photocatalytic water splitting
更新于2025-09-19 17:15:36
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An autodriven, solar fuel collection for a highly compact, biomimetic-modified artificial leaf without membrane
摘要： Hydrogen fuel generation from water splitting has recently attracted much attention due to its high potential as a clean, renewable energy source. To obtain pure H2 fuel, it is inevitably required to separate the H2/O2 product gas mixture, mainly relying on a membrane system at the current stage. However, this process has inherent durability and cost issues due to contamination, corrosion and its complex configuration. In our current work, we invented a highly compact gas separation and collection method in a water electrolysis system, which is set onto a biomimetically modified electrode without the use of a membrane or external convective flow. A key idea of this smart, compact and self-driven system is gas bubble manipulation by buoyant force and a slippery liquid infused porous surface (SLIPS). With the critical help of the biomimetic SLIPS wall by blocking bubble leakage, H2 and O2 product gases can be separately collected at the corresponding collection port. As a result, we achieved a remarkably improved H2 collection value of over 90 % with high purity using this membrane-free electrolysis system in which the product gases are separated only by their intrinsic buoyancy. This simple but effective gas separation/collection system is also applied to a highly compact, monolithic artificial leaf, in which the solar water splitting is practicably and conveniently conducted in a compact, floatable design.
关键词： artificial leaf,gas separation,underwater bubble manipulation,water splitting,biomimetic surface
更新于2025-09-19 17:15:36
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Janus Chromium Dichalcogenides Monolayers with Low Carrier Recombination for Photocatalytic Overall Water-Splitting under Infrared Light
摘要： Photocatalytic overall water-splitting is known as one of most promising methods to alleviate energy crisis. Searching for stable and efficient photocatalysts plays a critical role in this process. Here, we propose a novel class of Janus chromium dichalcogenides (CrXY, X/Y = S, Se, Te) monolayers serving as efficient photocatalysts for overall water-splitting under infrared light irradiation. We reveal that these Janus monolayers harbor an intrinsic dipole, which promotes the spatial separation of photo-generated carriers. More significantly, these systems exhibit suitable band gaps as well as band edge positions, enabling preeminent infrared optical absorption and high carrier mobility. Furthermore, the nonradiative recombination of photoinduced charge carriers in CrXY monolayers are evaluated based on time-domain density functional theory. The obtained long-lived excited carriers (~ 2 ns) are even comparable with that in transition-metal dichalcogenides heterostructures, which benefits for the photocatalytic reaction with high efficiency. Our results provide a new guidance for designing brand new photocatalytic systems with broad optical absorption and low carrier recombination.
关键词： infrared light,first principles calculations,carrier recombination,Janus chromium dichalcogenides,photocatalytic water-splitting
更新于2025-09-19 17:15:36
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Enhanced visible-light-photoconversion efficiency of TiO2 nanotubes decorated by pulsed laser deposited CoNi nanoparticles
摘要： The pulsed laser deposition (PLD) technique has been used to decorate TiO2 nanotubes (NTs) with cobalt-nickel (CoNi) nanoparticles (NPs). The TiO2 NTs were produced beforehand through the controlled anodic oxidation of titanium substrates. The effect of the nature of the PLD background gas (Vacuum, O2 and He) on the microstructure, composition and chemical bondings of the CoNi-NPs deposited onto the TiO2-NTs has been investigated. We found that the PLD CoNi-NPs have a core/shell (oxide/metal) structure when deposited under vacuum, while they are fully oxidized when deposited under O2. On the other hand, by varying the CoNi-NPs loading of the TiO2-NTs (through the increase of the number of laser ablation pulses (NLP)), we have systematically studied their photocatalytic effect by means of cyclic-voltammetry (CV) measurements under both AM1.5 simulated solar light and filtered visible light. We show that depositing CoNi-NPs on the substrate under vacuum and He increases the photo-electrochemical conversion effectiveness (PCE) by 600% (at NLP = 10,000) in the visible light domain, while their overall PCE degrades with NLP under solar illumination. In contrast, the fully oxidized CoNi-NPs (deposited under O2) are found to be the most effective catalyst under sunlight with an overall increase of more than 50% of the PCE at the optimum loading around NLP ~1000. Such catalytic enhancement is believed to result from both an enhanced light absorption by CoO (of which bandgap is of ~2.4 eV) and the formation of a heterojunction between NiO/CoO nanoparticles and TiO2 nanotubes.
关键词： TiO2 nanotubes,Pulsed laser deposition,Cobalt/nickel nanoparticles,Photo-electrochemistry,Water-splitting
更新于2025-09-19 17:13:59
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Tailored TiO <sub/>2</sub> Protection Layer Enabled Efficient and Stable Microdome Structured pa??GaAs Photoelectrochemical Cathodes
摘要： Group III–V compound semiconductors are a promising group of materials for photoelectrochemical (PEC) applications. In this work, a metal assisted wet etching approach is adapted to acquiring a large-area patterned microdome structure on p-GaAs surface. In addition, atomic layer deposition is used to deposit a TiO2 protection layer with controlled thickness and crystallinity. Based on a PEC photocathode design, the optimal configuration achieves a photocurrent of ?5 mA cm?2 under ?0.8 V versus Ag/AgCl in a neutral pH electrolyte. The TiO2 coating with a particular degree of crystallization deposited via controlled temperature demonstrates a superior stability over amorphous coating, enabling a remarkably stable operation, for as long as 60 h. The enhanced charge separation induced by favorable band alignment between GaAs and TiO2 contributes simultaneously to the elevated solar conversion efficiency. This approach provides a promising solution to further development of group III–V compounds and other photoelectrodes with high efficiency and excellent durability for solar fuel generation.
关键词： atomic layer deposition,GaAs,TiO2 coating,photocathode stability,photoelectrochemical water splitting
更新于2025-09-19 17:13:59
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Plasmonic gold sensitization of ZnO nanowires for solar water splitting
摘要： This paper reports the synthesis of plasmonic gold sensitized ZnO nanowires by chemical vapor deposition and subsequent photoreduction method. The well sensitization of Au nanoparticles with mean diameter of 5.3 nm on ZnO nanowires yield a higher photocurrent density of 1.06 mAcm-2 under illumination. Accordingly, Au nanoparticles on ZnO nanowires reveals the maximum photoelectrochemical water splitting efficiency of 0.45% at + 0.8 VRHE, which is higher than the ZnO nanowires (0.22% at + 0.8 VRHE). The enhanced photocurrent density and efficiency is due to the effective charge separation and transportation originating from metal support interaction, 1D nanostructure as well as surface plasmon resonance effect of Au nanoparticles.
关键词： Interfaces,Photoelectrochemical water splitting,Chemical vapor deposition,ZnO nanowires,Au nanoparticles
更新于2025-09-19 17:13:59
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Colour centre controlled formation of stable sub-nanometer transition metal clusters on TiO2 nanosheet for high efficient H2 production
摘要： The transition elements (Fe, Co, Ni) are important substitutes for noble metals as the co-catalysts in hydrogen evolution reaction. Enhancing the atom utilization efficiency is highly desirable, but preparation and preservation of the transition metal catalysts with the size downscaling to sub-nanometer are challenging. In this work, Fe, Co and Ni clusters with subnano size as co-catalysts are synthesized by controllable growth on 2D ultrathin TiO2(B) nanosheets for hydrogen evolution using a photo deposition method. The ultra-small Fe, Co, and Ni co-catalysts on the TiO2(B) nanosheets exhibit remarkably enhanced photo activities, compared to that with the best Pt loading. It is found that the oxygen bridge vacancies act as the colour centres locating at the position adjacent to the O1-Ti1 sites on the TiO2(B) (001) surface. The photo-colouration and photo-bleaching have significantly impact on the nucleation and growth of the metallic clusters. The high density and uniform dispersion of the sub-nano-sized transition metal clusters benefits for the photo reduction under light irradiation, as well as efficient carrier separation, leading to a great improvement of the photo activity.
关键词： TiO2(B),transition metal loading,photocatalysis,water splitting,sub-nanometer
更新于2025-09-19 17:13:59
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Carbon Nitride Hollow Theranostic Nanoregulators Executing Laser-Activatable Water Splitting for Enhanced Ultrasound/Fluorescence Imaging and Cooperative Phototherapy
摘要： The limited efficacy of “smart” nanotheranostic agents in eradicating tumors calls for the development of highly desirable nanoagents with diagnostics and therapeutics. Herein, to surmount these challenges, we constructed an intelligent nanoregulator by coating mesoporous carbon nitride (C3N4) layer on core-shell nitrogen-doped graphene quantum dot (N-GQD)@hollow mesoporous silica nanosphere (HMSN), and decorated it with a P-PEG-RGD polymer, to achieve active-targeting delivery (designated as R-NCNP). Upon irradiation, the resultant R-NCNP nanoregulators exhibit significant catalytic breakdown of water molecules causing sustainable elevation of oxygen level owing to the C3N4 shell, which facilitates tumor oxygenation and relieves tumor hypoxia. The generated oxygen bubbles serve as an echogenic source triggering tissue impedance mismatch thereby enhancing the generation of echogenicity signal, making them laser-activatable ultrasound imaging agents. In addition, the encapsulated photosensitizers and C3N4 layered photosensitizer are simultaneously activated to maximize the yield of ROS, actualizing a triple-photosensitizer hybrid nanosystem exploited for enhanced PDT. Intriguingly, the N-GQDs endow R-NCNP nanoregulator with photothermal effect for hyperthemia, making it exhibit considerable photothermal outcomes and infrared thermal imaging (IRT). Importantly, further analysis reveals that the polymer-modified R-NCNPs actively target specific tumor tissues, and display a triple-modal US/IRT/FL imaging-assisted cooperative PTT/PDT for real-time monitoring of tumor ablation and therapeutic evaluation. The rational synergy of triple-model PDT and efficient PTT in designed nanoregulator confers excellent anticancer effects, as evidenced by in vitro and in vivo assays, which might explore more possibilities in personalized cancer treatment.
关键词： O2-elevation,ultrasound imaging,water splitting,cancer treatment,nanoregulator
更新于2025-09-19 17:13:59