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In-situ Platinum Plasmon Resonance Effect Prompt Titanium Dioxide Nanocube Photocatalytic Hydrogen Evolution
摘要： In-situ photodeposition Pt nanoparticles (Pt NPs) on TiO2 on account of the surface plasmonic resonance (SPR) effect and strong interaction of two components, which exhibits an elevated solar-driven photocatalytic hydrogen evolution performance. Herein, Pt-decorated TiO2 nanocube hierarchy structure (Pt-TNCB) was in-situ fabricated via a facile solvothermal synthesis and photodeposition strategy. The Pt-TNCB exhibits an excellent solar-driven photocatalytic hydrogen evolution rate (337.84 μmol h-1), which is about 37 times higher than that of TNCB (9.19 μmol h-1). Interestingly, its photocatalytic property is still superior to TNCB with post modification Pt (1 wt %) (208.11 μmol h-1). The introduction of Pt efficiently extends the photoresponse of composite material from UV to visible light region, simultaneously boost their solar-driven photocatalytic performance, which attribute to the porous structure, the subsize TNCB, the SPR effect of Pt NPs and strong interaction of two components. In fact, Pt NPs can enhance collective oscillations on delocalized electrons, which is conducive to capture electrons and hinder the recombination of photogenerated electron-hole pairs, leading to the longer lifetime of photogenerated charges. The fabrication of Pt-TNCB photocatalyst with SPR effect may provide a promising method to improve visible-light photocatalytic activities for traditional photocatalysts.
关键词： hydrogen evolution,titanium dioxide,surface plasmonic resonance,photodeposition,photocatalyst
更新于2025-09-23 15:22:29
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Mechanistic Study on Facet-Dependent Deposition of Metal Nanoparticles on Decahedral-Shaped Anatase Titania Photocatalyst Particles
摘要： Facet-selective gold or platinum-nanoparticle deposition on decahedral-shaped anatase titania particles (DAPs) exposing {001} and {101} facets via photodeposition (PD) from metal-complex sources was reexamined using DAPs prepared with gas-phase reaction of titanium (IV) chloride and oxygen by quantitatively evaluating the area deposition density on {001} and {101} and comparing with the results of deposition from colloidal metal particles in the dark (CDD) or under photoirradiation (CDL). The observed facet selectivity, more or less {101} preferable, depended mainly on pH of the reaction suspensions and was almost non-selective at low pH regardless of the deposition method, PD or CDL, and the metal-source materials. Based on the results, the present authors propose that facet selectivity is attributable to surface charges (zeta potential) depending on the kind of facets, {001} and {101}, and pH of the reaction mixture and that this concept can explain the observed facet selectivity and possibly the reported facet selectivity without taking into account facet-selective reaction of photoexcited electrons and positive holes on {101} and {001} facets, respectively.
关键词： zeta potential,pH dependence,facet-selective reaction,facet-selective metal photodeposition,{001} and {101} facets,decahedral-shaped anatase titania particles
更新于2025-09-23 15:22:29
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Photodeposition of palladium nanoparticles on a porous gallium nitride electrode for nonenzymatic electrochemical sensing of glucose
摘要： A nonenzymatic electrochemical glucose sensor is described that was obtained by in situ photodeposition of high-density and uniformly distributed palladium nanoparticles (PdNPs) on a porous gallium nitride (PGaN) electrode. Cyclic voltammetric and chronoamperometric techniques were used to characterize the performance of the modified electrode toward glucose. In 0.1 M NaOH solution, it has two linear detection ranges, one from 1 μM to 1 mM, and another from 1 to 10 mM, and the detection limit is 1 μM. The electrode is repeatable, highly sensitive, fast and long-term stable. It was applied to the quantitation of serum glucose where it displayed accurate current responses.
关键词： Electrochemical sensing,Gallium nitride,Photodeposition,Glucose detection,Palladium nanoparticles,Porous materials
更新于2025-09-23 15:22:29
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Influence of Substrates on the Long-Range Order of Photoelectrodeposited Se-Te Nanostructures
摘要： The long-range order of anisotropic phototropic Se-Te films grown electrochemically at room temperature under uniform intensity, polarized, incoherent near-IR illumination has been investigated using crystalline (111)-oriented Si substrates doped degenerately with either p- or n-type dopants. Fourier-transform (FT) analysis was performed on large-area images obtained with a scanning electron microscope, and peak shapes in the FT spectra were used to determine the pattern fidelity in the deposited Se-Te films. Under nominally identical illumination conditions, phototropic films grown on p+-Si(111) exhibited a higher degree of anisotropy and a more well-defined pattern period than phototropic films grown on n+-Si(111). Similar differences in the phototropic Se-Te deposit morphology and pattern fidelity on p+-Si vs. n+-Si were observed when the deposition rate and current densities were controlled for by adjusting the deposition parameters and illumination conditions. The doping-related effects of the Si substrate on the pattern fidelity of the phototropic Se-Te deposits is ascribable to an electrical effect produced by the different interfacial junction energetics between Se-Te and p+-Si vs n+-Si that influences the dynamic behavior during phototropic growth at the Se-Te/Si interface.
关键词： interface,photodeposition,chalcogenide,Electrodeposition,photoelectrochemistry,nanopatterning
更新于2025-09-19 17:15:36
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The Role Played by Graphene Oxide in the Photodeposition and SERS Activity of Plasmonic Ag Nanoparticles Substrates
摘要： Ag nanoparticles substrates deposited by a photocatalytic method display SERS activity for rhodamine B, which is enhanced further by the fluorescence quenching promoted by graphene oxide.
关键词： SERS effect,rhodamine B,graphene oxide,Ag nanoparticles,photodeposition
更新于2025-09-16 10:30:52
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Solar Light Induced Photon-Assisted Synthesis of TiO2 Supported Highly Dispersed Ru Nanoparticle Catalysts
摘要： Ru/TiO2 are promising heterogeneous catalysts in different key-reactions taking place in the catalytic conversion of biomass towards fuel additives, biofuels, or biochemicals. TiO2 supported highly dispersed nanometric-size metallic Ru catalysts were prepared at room temperature via a solar light induced photon-assisted one-step synthesis in liquid phase, far smaller Ru nanoparticles with sharper size distribution being synthesized when compared to the catalysts that were prepared by impregnation with thermal reduction in hydrogen. The underlying strategy is based on the redox photoactivity of the TiO2 semi-conductor support under solar light for allowing the reduction of metal ions pre-adsorbed at the host surface by photogenerated electrons from the conduction band of the semi-conductor in order to get a ?ne control in terms of size distribution and dispersion, with no need of chemical reductant, ?nal thermal treatment, or external hydrogen. Whether acetylacetonate or chloride was used as precursor, 0.6 nm sub-nanometric metallic Ru particles were synthesized on TiO2 with a sharp size distribution at a low loading of 0.5 wt.%. Using the chloride precursor was necessary for preparing Ru/TiO2 catalysts with a 0.8 nm sub-nanometric mean particle size at 5 wt.% loading, achieved in basic conditions for bene?tting from the enhanced adsorption between the positively-charged chloro-complexes and the negatively-charged TiO2 surface. Remarkably, within the 0.5–5 wt.% range, the Ru content had only a slight in?uence on the sub-nanometric particle size distribution, thanks to the implementation of suitable photo-assisted synthesis conditions. We demonstrated further that a ?ne control of the metal Ru nanoparticle size on the TiO2 support was possible via a controlled nanocluster growth under irradiation, while the nanoparticles revealed a good resistance to thermal sintering.
关键词： highly dispersed Ru nanoparticle,sub-nanometric particle size distribution,catalyst preparation,reaction mechanism,Ru/TiO2 catalyst,photodeposition,photon-assisted synthesis
更新于2025-09-10 09:29:36
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Photoactive ZnO Materials for Solar Light-Induced CuxO-ZnO Catalyst Preparation
摘要： In this work, the solar light-induced redox photoactivity of ZnO semiconductor material was used to prepare CuxO-ZnO composite catalysts at room temperature with a control of the chemical state of the copper oxide phase. Cu2(I)O-ZnO and Cu(II)O-ZnO composite catalysts were prepared by using Cu(acac)2 in tetrahydrofuran-water and Cu(NO3)2 in water as metallic precursor, respectively. Prior to the implementation of the photon-assisted synthesis method, the most efficient photoactive ZnO material was selected from among different ZnO materials prepared by the low temperature polyol and precipitation methods with carbonates and carbamates as precipitation agents. The photocatalytic degradation of the 4-chlorophenol compound in water under simulated solar light was taken as a model reaction. The ZnO support materials were characterized by X-ray diffraction (XRD), surface area and porosimetry measurements, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the synthesis method strongly influenced their photoactivity in terms of 4-chlorophenol degradation and of total organic carbon removal. The most photoactive ZnO material was prepared by precipitation with carbonates and calcined at 300 ?C, benefiting from a high specific surface area and a small mean crystallite size for achieving a complete 4-chlorophenol mineralization within 70 min of reaction, with minimum Zn2+ released to the solution. Besides thermal catalysis applications, this work has opened a new route for the facile synthesis of Cu2O-ZnO heterojunction photocatalysts that could take place under solar light of the heterojunction built between the p-type semi-conductor Cu2O with direct visible light band gap and the ZnO semiconductor phase.
关键词： ZnO,CuxO-ZnO catalyst,photo-oxidation,4-chlorophenol,photodeposition
更新于2025-09-09 09:28:46