- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Synthesis of CoNi bimetallic alloy nanoparticles wrapped in nitrogen-doped graphite-like carbon shells and their electrocatalytic activity when used in a counter electrode for dye-sensitized solar cells
摘要： Nanoparticles of the bimetallic alloy CoNi wrapped in nitrogen-doped graphite-like carbon shells and dispersed on nitrogen-doped graphite-like carbon sheets (CoxNi1?x@NC) were synthesized by calcining CoNi metal–organic frameworks that were prepared through a facile solvothermal reaction using various raw-material molar ratios Co:Ni and CoNi:ethylenedinitrilotetraacetic acid. After depositing CoxNi1?x@NC for use as a counter electrode film in dye-sensitized solar cells, it was found that the electrocatalytic activity of the CoxNi1?x@NC counter electrode towards triiodide reduction could be optimized by simply tuning the molar ratios (Co:Ni and CoNi:ethylenedinitrilotetraacetic acid) appropriately during CoxNi1?x@NC synthesis. Cells that utilized a CoxNi1?x@NC counter electrode exhibited strong chemical-composition-dependent photovoltaic performance. Under optimal conditions, the CoxNi1?x@NC counter electrode presented an impressive energy conversion efficiency of 3.58%, suggesting that it is a highly promising counter electrode for application in dye-sensitized solar cells. This counter electrode has the advantages that it is considerably less expensive than a Pt counter electrode and that it provides the basis for the design and preparation of other inexpensive and efficient counter electrodes to replace Pt.
关键词： Photovoltaic performance,Dye-sensitized solar cells,CoNi alloy bimetallic nanoparticles,Counter electrode,Electrocatalytic activity
更新于2025-11-14 17:04:02
-
Cu-Zn and Cu-Ni Bimetallic Particles Fabricated Using Ascorbic Acid and Its Role in Photodegradation of Methyl Orange
摘要： Chemical reduction of metal salts using ascorbic acid (vitamin C) is a new and green approach in which ascorbic acid serve dual role of reducing and capping agent. Copper, zinc and nickel salts were reduced by ascorbic acid to give bimetallic nanoparticles. SEM images highlight the aggregation of nanoparticles, which is due to the high surface energy of the particles in nano range. Bimetallic particles fabricated are in the weight ratio of 4:1. Subsequent shift of surface plasma resonance band and XRD peaks indicate that the particles are not just a physical mixture of mono metallic particles. UV-visible spectra and XRD result rule out the alloy nature of the particles. Average size of the particles were calculated using XRD data and are in nano scaled. Size of the Cu, Cu-Zn and Cu-Ni particles as calculated by using Scherrer’s equation are 43.47, 38.4 and 43.5 nm, respectively. In this work photo degradation of methyl orange has been studied to demonstrate the catalytic properties of mono and bimetallic particles. Bimetallic particles have superior catalytic application as compared to monometallic particles. These alloying of metals might have result in change of certain electronic configuration, which significantly increase the catalytic application of bimetallic nanoparticles.
关键词： Methyl orange,Ascorbic acid,Bimetallic,Catalytic properties
更新于2025-09-23 15:23:52
-
Wide Spectrum Photocatalytic Activity in Lanthanide-doped Upconversion Nanophosphors Coated with Porous TiO2 and Ag-Cu Bimetallic Nanoparticles
摘要： Approaches towards maximum utilization of solar light spectrum for photocatalysis have currently attracted great interest. The combination of profoundly different properties, such as, upconversion, semiconducting and plasmonic properties can produce a favorable path in efficient utilization of the different regions of solar light reaching to earth. In this regard, design and fabrication of microstructures consisting of upconverting lanthanide doped nanophosphors coated with porous semiconducting material, TiO2 and decorated with plasmonic Ag-Cu bimetallic nanoparticles is presented in this work. These microstructures display great stability and exceptional photocatalytic activity by absorbing wide spectrum from ultraviolet to near infrared. The photocatalytic activity could be attributed to the synergistic effects between the different components and the efficient energy transfer between them. The development of such sort of hybrid microstructures could pave way for the development of new materials for the efficient utilization of the wide spectrum of sunlight.
关键词： bimetallic plasmonic nanoparticles,titania,wide spectrum utilization,photocatalysis,Upconversion nanophosphors
更新于2025-09-23 15:23:52
-
Core-shell structure of ZnO/Co3O4 composites derived from bimetallic-organic frameworks with superior sensing performance for ethanol gas
摘要： In recent years, metal-organic frameworks (MOFs), especially zeolite-imidazole frameworks (ZIFs), have been attracting widespread attention as templates for the synthesis of sensing materials. Limited researches, however, have been carried out to utilize bimetallic ZIFs in gas sensing, as the existing studies mostly involve mono-metallic ZIFs. Here in, the core-shell structure of ZnO and Co3O4 composite (CS-ZnO/Co3O4) was synthesized via chemical etched to Co/Zn based zeolitic imidazolate framework (Co/Zn-ZIF) with subsequent annealing. The morphology, composition and surface characteristics of the as-obtained samples were confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscope (TEM) and Brunauer-Emmett-Teller (BET). Moreover, the gas sensing measurements were implemented under various atmospheres. The response of CS-ZnO/Co3O4 sensor to 100 ppm ethanol at 200 °C achieves 38.87, which is 2.8 times that of single-shell ZnO/Co3O4 (SS-ZnO/Co3O4). The improved response is mainly attributed to the core-shell structure, which offers larger surface area, more active sites for gas diffusion and the formation of p-n heterojunction between ZnO and Co3O4.
关键词： Bimetallic-organic framework,Core-shell structure,ZnO/Co3O4,Ethanol gas sensor
更新于2025-09-23 15:23:52
-
Highly efficient H2 production over NiCo2O4 decorated g-C3N4 by photocatalytic water reduction
摘要： Herein, ternary nickel cobalt oxide (NiCo2O4) was firstly employed to increase the photocatalytic water reduction ability of g-C3N4. 17.5wt%-NiCo2O4/g-C3N4 shows excellent water splitting performance with a H2 production rate of 5480 μmol·h-1·g-1, which is extremely better than that of Co3O4, NiO, Pt modified g-C3N4. The quantum efficiency of 17.5wt%-NiCo2O4/g-C3N4 can reach 4.5% under 400 (±7.5) nm light irradiation. The greatly increased activity of 17.5wt%-NiCo2O4/g-C3N4 can be attributed to the richer active sites and the superior electrical performance provided by co-existing nickel and cobalt ions with multivalent state. Moreover, the activity of composite almost shows no significant weaken even after 20 h irradiation. A Z-scheme route was put forwarded for H2 production over NiCo2O4/g-C3N4 instead of the traditional p-n junction based on our study.
关键词： NiCo2O4,bimetallic complex,photocatalysis,hydrogen evolution
更新于2025-09-23 15:23:52
-
Atomically Precise Bimetallic Nanoclusters as Photosensitizers in Photoelectrochemical Cells
摘要： The atomically precise bimetallic nanocluster, Au24Ag20(PhCC)20(SPy)4Cl2 (1), is for the first time employed as a stable photosensitizer for photoelectrochemical applications. The sensitization of TiO2 nanotube arrays (TNA) with 1 greatly enhances the light harvest ability of the composite, as 1 shows high molar-extinction-coefficient in the UV-Vis region. Compared to a more standard Au25(SG)18 -TNA (2-TNA, SG: Glutathione), 1-TNA shows a much better stability under illumination both in neutral and basic conditions. The precise composition of the photosensitizers enables a direct comparison of the sensitization ability between 1 and 2. With the same cluster loading, the photocurrent produced by 1-TNA is 15 times larger than 2-TNA. The superior performance of 1-TNA over 2-TNA is attributed not only to the higher light absorption ability of 1, but also to the higher charge-separation efficiency. Besides, a ligand effect on the stability of the photoelectrode and charge-transfer between the NCs and the semiconductor is revealed. Our work paves the way to study the role of metal nanoclusters as photosensitizers at the atomic level, which is essential for the design of better material for light energy conversion.
关键词： Energy Conversion,Bimetallic Nanoclusters,Photosensitizers,Nanostructured Materials,Photoelectrochemical Cells
更新于2025-09-23 15:23:52
-
Growth of Spherical Gold Satellites on the Surface of Au@Ag@SiO <sub/>2</sub> Core–Shell Nanostructures Used for an Ultrasensitive SERS Immunoassay of Alpha-Fetoprotein
摘要： The identification and detection of cancer biomarkers in early stages is an important issue for the therapy of cancer. However, most methods are time-consuming, limited sensing sensitivity and specificity. In this work, we prepared a novel plasmonic multilayered core–shell-satellite nanostructure (Au@Ag@SiO2-AuNP) consisting of an gold nanosphere with silver coating core (Au@Ag), an ultrathin continuous silica (SiO2) shell and high coverage of gold nanospheres (AuNPs) satellites. Au@Ag core is prominent surface enhanced Raman scattering (SERS) platform and the thin SiO2 layer exhibits a long-range plasmon coupling between Au@Ag core to AuNPs satellites further leading to enhanced Raman scattering. Meanwhile, the outer AuNPs satellites have a high biocompatibility and long-term stability. Combining the above advantages, the well-designed metallic nanoassemblies would be a promising candidate for SERS-based applications in biochemistry. For specific detection of alpha-fetoprotein (AFP), we utilized the SERS-active core-shell-satellite nanostructures modified with AFP antibody as immune probes and nitrocellulose membrane (NC) stabilized captured anti-AFP antibodies as solid substrate. To improve the detection performance, we further systematically optimized the parameters, including silver coating thickness of Au@Ag core, the density and size of satellite AuNPs. Under the optimized conditions, AFP could be detected by the SERS-based sandwich immunoassay with an ultralow detection limit of 0.3 fg/mL, and the method exhibited a wide linear response from 1 fg/mL to 1 ng/mL. The limit of detection (LOD) was considerably lower than conventional methods in literature. This work relies on the unique Au@Ag@SiO2-AuNP nanostructures as immune probe develops a new outlook for the application of multilayered nanoassemblies and demonstrates the great potential in early tumor markers detection.
关键词： surface enhanced Raman scattering (SERS),Au-Ag bimetallic nanospheres,alpha-fetoprotein,core-shell-satellite nanostructure,gold nanospheres
更新于2025-09-23 15:22:29
-
Thermal decomposition of bimetallic titanium complexes: A new method for synthesizing doped titanium nano-sized catalysts and photocatalytic application
摘要： In this study, synthesis of bimetallic (Co, Mn, and Ni) complexes of salicylic acid (L1) and 1,2 dihydroxybenzene (L2) based on titanium(IV) were investigated, then the samples were decomposed by thermal method to obtain MxTiyOz nanoparticles (M = Ni, Co, and Mn). The samples in complexes mode were analyzed by UV–Vis (200–800 nm), FT-IR (4000–400 Cm?1), CHN analysis and the structure of the bimetallic compounds also were investigated by the Quantum-chemical modelling. In addition, the samples in nanoparticles mode were studied by thermal analysis (to obtain DTA curves), XRD, FESEM image and EDX analyzing. BET surface analysis was carried out to analyze active surface, pore diameter and porosity of the MxTiyOz nanoparticles. Based on the results, obtained samples as catalysts were able to absorb not just UV but also visible light. Catalysts were able to degrade bromophenol blue as a harmful organic substance under UV and visible lights, although, this ability was more significant when the samples were used under visible light.
关键词： Photocatalysis,1,2 Dihydroxy benzene,Bimetallic complex,Doped titanium,Salicylic acid
更新于2025-09-23 15:22:29
-
Invisible-ink-assisted pattern and written surface-enhanced Raman scattering substrates for versatile chem/biosensing platforms
摘要： In recent years, highly sensitive surface-enhanced Raman scattering (SERS) integrated with flexible substrates has drawn increasing attention for label-free detection. In this study, an invisible ink-inspired process was developed for the fabrication of plasmonic Au-based SERS substrates through an on-site redox strategy. Tannic acid (TNA), a common green reagent, was used not only for fabricating various SERS absorbents through a confinement reduction of a Au-TNA complex, but also for supplying an amphiphilic inorganic–organic surface structure for outstanding SERS enhancement at micromolar to nanomolar concentrations for a wide range of compounds. In addition to label-free sensing, this TNA/Au-based SERS substrate provides a versatile analysis platform for studies of chemical and biological reactions. A combination of TNA ink with different metal ions allows for a reliable procedure for the synthesis of a bimetallic AuAg SERS substrate that further enhances the SERS intensity of analyte molecules and extends the lower limit of detection.
关键词： bimetallic AuAg SERS substrate,invisible ink,tannic acid,label-free detection,SERS,plasmonic Au-based SERS substrates,surface-enhanced Raman scattering
更新于2025-09-23 15:21:21
-
Bimetallic PtNi/g-C3N4 nanotubes with enhanced photocatalytic activity for H2 evolution under visible light irradiation
摘要： Bimetallic PtNi-decorated graphitic carbon nitride (g-C3N4) nanotubes were prepared through calcining the mixture of urea and thiourea in the presence of Pluronic F127, followed by deposition of bimetallic PtNi nanoparticles (NPs) via chemical reduction. It is found that the photocatalytic activity of PtNi/g-C3N4 nanotubes is strongly dependent on the molar ratio of Pt/Ni and the highest activity is observed for Pt1Ni1/g-C3N4. Under visible light (l > 420 nm) irradiation, the H2 generation rate over Pt1Ni1/g-C3N4 nanotubes is 104.7 mmol h?1 from a triethanolamine (10 vol%) aqueous solution, which is higher than that of Pt/g-C3N4 nanotubes (98.6 mmol h?1) and is about 47.6 times higher than that of pure g-C3N4 nanotubes. The cyclic photocatalytic reaction indicates that our Pt1Ni1/g-C3N4 nanotubes function as a stable photocatalyst for visible light-driven H2 production. The effect of bimetallic PtNi NPs in the transfer and separation of photogenerated charge carriers occurring in the excited g-C3N4 nanotubes was investigated by performing photoelectrochemical and photoluminescence measurements. Our results reveal that bimetallic PtNi could replace Pt as a promising cocatalyst for photocatalytic H2 evolution with better performance and lower cost.
关键词： Hydrogen evolution,g-C3N4,Nanotube,Bimetallic PtNi,Photocatalyst
更新于2025-09-23 15:21:21