共查询到10条相似文献,搜索用时 0 毫秒
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《Advanced Powder Technology》2022,33(3):103511
In this paper, plasmonic Ag and Cu nanoparticles were co-deposited on TiO2 nanoring/nanotube arrays (TiO2 R/T) by using two-step pulse electrodeposition method for investigating the optical and photoelectrochemical properties, in comparison to monometallic Ag, Cu decoration. By optimizing the electrodeposition cycle times and electrolyte concentration, bimetallic Ag–Cu/TiO2 R/T-0.5 with moderate densities and sizes of Ag and Cu nanoparticles was fabricated and shows great photocatalytic potential, in which, Ag mainly facilitates the generation of hot electrons by absorbing visible light and Cu plays an important role in accelerating the separation and transportation of hot electrons. The hydrogen production rate was tested as 425 μL h?1 cm?2, which is about 1.34-fold enhanced H2 production over TiO2 R/T. Furthermore, molecular dynamics simulations were made for analyzing the interface electrostatic properties between plasmonic nanoparticles of Ag or Cu and the semiconductor TiO2. It is calculated that bimetallic Ag–Cu/TiO2/H2O system has larger interfacial Helmholtz potential than monometallic Ag/TiO2/H2O, Cu/TiO2/H2O and pure TiO2/H2O systems, accelerating the four-electron reaction occurring at the semiconductor/electrolyte interface. This research put forward a feasible and simple pulse electrodeposition method to fabricate bimetallic photoanodes for enhanced hydrogen evolution and an important analysis method of semiconductor/ metal/electrolyte interface characteristics. 相似文献
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Monika Gupta Vidhika Sharma Jaya Shrivastava Anjana Solanki A. P. Singh V. R. Satsangi S. Dass Rohit Shrivastav 《Bulletin of Materials Science》2009,32(1):23-30
Nanostructured zinc oxide thin films (ZnO) were prepared on conducting glass support (SnO2: F overlayer) via sol-gel starting from colloidal solution of zinc acetate 2-hydrate in ethanol and 2-methoxy ethanol. Films
were obtained by spin coating at 1500 rpm under room conditions (temperature, 28–35°C) and were subsequently sintered in air
at three different temperatures (400, 500 and 600°C). The evolution of oxide coatings under thermal treatment was studied
by glancing incidence X-ray diffraction and scanning electron microscopy. Average particle size, resistivity and bandgap energy
were also determined. Photoelectrochemical properties of thin films and their suitability for splitting of water were investigated.
Study suggests that thin films of ZnO, sintered at 600°C are better for photoconversion than the films sintered at 400 or
500°C. Plausible explanations have been provided. 相似文献
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In this study, a potentially universal new strategy is reported for the large-scale, low-cost fabrication of visible-light-active highly ordered heteronanostructures based on the spontaneous photoelectric-field-enhancement effect inherent in pyramidal morphology. The hierarchical vertically oriented arrayed structures comprise an active molecular co-catalyst at the apex of a visible-light-active large band gap semiconductor for low-cost solar water splitting in a neutral aqueous medium without the use of a sacrificial agent. 相似文献
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Surface-enhanced Raman scattering spectroscopy as a sensitive and selective technique for the detection of folic acid in water and human serum 总被引:1,自引:0,他引:1
Surface-enhanced Raman scattering (SERS) is shown to give linear and sensitive concentration-dependent detection of folic acid using silver nanoparticles created via ethylene-diaminetetraacetic acid (EDTA) reduction. Optical detection by SERS overcomes the primary limitation of photodissociation encountered during the application of other shorter wavelength ultraviolet (UV)/near-UV techniques such as fluorescence based microscopy. The SERS approach in water-based samples was demonstrated and optimized using several longer wavelengths of excitation (514.5, 632.8, and 785 nm). Excitation in the green (514.5 nm) was found to achieve the best balance between photodissociation and SERS efficiency. Linear concentration dependence was observed in the range of 0.018 to 1 microM. The importance of folic acid in a clinical setting and the potential applications of this technique in a biological environment are highlighted. We demonstrate the potential to transfer this technique to real biological samples by the detection of folic acid in human serum samples by SERS. 相似文献
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HyukSu Han Ju Won Paik MinJi Ham Kang Min Kim Jin Kuen Park Young Kyu Jeong 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(33)
Transition metal (TM)‐based carbon hybrids have numerous applications in the field of regenerative electrochemical energy. The synergetic effects of high conductivity of carbon supports and abundant catalytic active sites in TMs make these hybrids promising oxygen evolution reaction (OER) electrocatalysts. However, strategies for modulating the catalytic active species in the above hybrids are limited despite being highly sought after. Furthermore, the exact roles of chemical species in the hybrids (e.g., N, C, or TM) mainly responsible for this high OER performance remain unknown. Herein, an innovative approach based on atomic layer deposition is developed to tune the true active species in Co nanoparticle/N‐doped carbon nanotube (Co/N‐CNT) hybrids. Specifically, the configuration predominantly promoting water oxidation in an alkaline medium is identified as pyridinic N–Co–C. Furthermore, a physicochemical intact interface between metallic Co nanoparticles and conductive N‐CNTs is demonstrated to induce synergetic effects for accelerating charge transfer and enhancing electrocatalytic activity as well as stability in the hybrid catalysts. The optimized hybrid catalyst is revealed to exhibit outstanding alkaline OER activity and stability, outperforming RuO2, a benchmark novel OER electrocatalyst. 相似文献
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Qin Li Ding Ruimin Wang Huixiang Wu Jianghong Wang Conghui Zhang Chenghua Xu Yao Wang Liancheng Lv Baoliang 《Nano Research》2017,10(1):305-319
Nano Research - Nitrogen-doped graphene is a promising candidate for the replacement of noble metal-based electrocatalysts for oxygen reduction reactions (ORRs). The addition of pores and holes... 相似文献
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Zhengxiu Luo Ning Wang Xiaoyan Pei Tao Dai Zhigang Zhao Congmei Chen Maofei Ran Wenjing Sun 《材料科学技术学报》2021,82(23):197-206
Heterogeneous Pd nanocatalysts are efficient catalysts for the Heck reaction but require multi-step,sophisticated procedures and harsh reaction conditions.In this work,a green and facile strategy has been developed to decorate Pd nanoparticles on polydopamine(PDA)-coated multi-walled carbon nano-tubes(Pd/CNTs-PDA)via a one-pot method.The obtained nanoparticles were characterized by various techniques including transmission electron microscopy,X-ray diffraction,and X-ray photoelectron spec-troscopy,which proved that Pd NPs are well-dispersed on the PDA and between the surfaces of the PDA and CNTs.The resultant Pd/CNTs-PDA catalysts exhibit excellent catalytic reactivity toward the Heck reaction at low temperatures.Moreover,by DFT simulation,we found that during the PDA polymeriza-tion process,a large number of unsaturated-N=and C=O species are more active than the groups on the PDA end product to anchor Pd NPs.The results provide evidence that the catalyst synthesized by the one-pot method exhibited good activity because sufficient active sites could be created to effectively promote Pd NPs dispersion during the dopamine polymerization process.Additionally,the Pd/CNTs-PDA catalyst was successfully employed in Heck cross-coupling reactions with various functionalized substrates.This method opens a window for the fabrication of high-performance nanocomposite catalysts under mild conditions using simple methods and has several potential applications. 相似文献
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Integrated water resources management practice is gaining popularity as an alternative water source due to the limited supply of freshwater. The present study was carried out on the photocatalytic degradation of Direct red 28 (DR-28) dye using magnetic nanoparticles (MNPs; Fe3O4) as a photocatalyst. The study was conducted on the photocatalytic degradation of DR-28 dye in synthetic dye effluent water, to understand the effects of different photoreaction parameters on the degradation kinetics. The influence of different parameters such as time, amount of photocatalyst, concentration of H2O2 and pH was investigated. At the optimum dosage of MNPs (0.6?g/L) with 4?mmol/L of H2O2, significant photocatalytic degradation of DR-28 dye (93.2%) was observed. The kinetic study revealed that the photocatalytic degradation followed pseudo-first-order kinetics. The degradation performance of Fe3O4 nanoparticles as a photocatalyst for DR-28 dye was compared with titanium dioxide (TiO2) and it was found that the performance of Fe3O4 as a photocatalyst is superior to TiO2 photocatalyst. The real dye effluent was also degraded at optimum conditions and promising results were achieved. 相似文献