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Physicochemical Interaction of ZnO Fine Particles with 5‐Mono‐(4‐carboxyphenyl)‐10,15,20‐Triphenylporphyrin
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This study deals with an investigation on the preparation and physicochemical interactions of ZnO nanoparticles with acid functionalized porphyrin [5‐mono‐(4‐carboxyphenyl)‐10,15,20‐triphenylporphyrin (CPTPP)] for photovoltaic applications in a detailed manner. Zinc acetate and sodium hydroxide were used as the starting materials for the synthesis of ZnO nanoparticles at 60 °C in an alcoholic medium. The freshly prepared fine particles were then functionalized with CPTPP. Both the virgin and pregnant ZnO particles were characterized by using UV‐Visible spectrophotometry (UV), fluorescence emission (PL), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The band gap energy obtained for ZnO particles, having a value of 3.47 eV, shows significant quantum confinement effect and enhanced photophysical activity. FTIR analysis of the doped ZnO nanostructures showed the presences of some chemical species. SEM analysis revealed a clear change in the surface morphologies of undoped ZnO. The average crystallite size of nanoparticles, calculated from XRD peaks, was found in the nano regime. The lattice parameters calculated for ZnO nanocrystals were also found in good agreement with those given in the literature. From the enhancement in the red shift of the UV‐Vis spectra, it is concluded that hybridization of acid functionalized porphyrin can cause a significant expansion in the total absorption region of ZnO semiconductor for photovoltaic applications. 相似文献
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The tandem hydrolysis and hydrogenation of saccharides into sorbitol is an especially attractive reaction in the conversion of biomass. Here, an economical and efficient bimetallic catalyst for the transformation of glucose and cellobiose into sorbitol is reported. Non-precious metal based catalysts such as NiCo, Ni, and Co, were prepared via modified impregnation method, and NiCo/HZSM-5 showed superior performance for the synthesis of sorbitol (86.9% from cellobiose, 98.6% from D-glucose). Various characterizations, such as Brunner-Emmet-Teler (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), confirmed that NiCo alloy formed and highly dispersed in NiCo/HZSM-5 catalyst. The high performance of fabricated catalyst would be attributed to the formation of nickel-cobalt alloy over HZSM-5 zeolite surface. High temperature and H2 pressure were favorable for the tandem hydrolysis and hydrogenation reaction. Besides, the reaction pathway was also proposed based on the kinetics study. Cellobitol was detected as the intermediate in the reaction mixture. Furthermore, in the catalytic stability study, it was found that active metal species of NiCo/HZSM-5 were stable. The deactivation of catalyst would be due to the covering of acidic sites over NiCo/HZSM-5. 相似文献
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We investigate self and cross-Kerr nonlinearity in a four level quantized graphene atomic medium. The absorption, dispersion, transmission and subluminal/superluminal behaviors of a probe light field are studied. An amplification of the probe light field is observed in the absorption spectrum. The normal and anomalous slope of dispersion is also investigated at the positive/negative absorption region. It is shown that Kerr nonlinearity invert and enhance the subluminal/superluminal behaviors of the pulse and self-Kerr effect is found to be more subluminal/superluminal as compared to cross-Kerr effect. The results show significant applications in information storage, self and cross phase modulation and lasing without inversion. 相似文献
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We demonstrate the possibility of creating a time gap in the slow light based on spectral hole burning in a fourlevel Doppler broadened sodium atomic system. A time gap is also observed between the slow and the fast light in the hole burning region and near the burnt hole region, respectively. A cloaking time gap is attained in microseconds and no distortion is observed in the transmitted pulse. The width of the time gap is observed to vary with the inverse Doppler effect in this system. Our results may provide a way to create multiple time gaps for a temporal cloak. 相似文献
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Akbar Zada Shaleena Shaleena Tongxing Li 《Mathematical Methods in the Applied Sciences》2019,42(4):1151-1166
In this paper, we interrogate different Ulam type stabilities, ie, β–Ulam–Hyers stability, generalized β–Ulam–Hyers stability, β–Ulam–Hyers–Rassias stability, and generalized β–Ulam–Hyers–Rassias stability, for nth order nonlinear differential equations with integrable impulses of fractional type. The existence and uniqueness of solutions are investigated by using the Banach contraction principle. In the end, we give an example to support our main result. 相似文献
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Muhammad Zada Liwei Guo Randi Zhang Wenjuan Zhang Yanping Ma Gregory A. Solan Yang Sun Wen‐Hua Sun 《应用有机金属化学》2019,33(5)
Five examples of unsymmetrical 1,2‐bis (arylimino) acenaphthene ( L1 – L5 ), each containing one N‐2,4‐bis (dibenzocycloheptyl)‐6‐methylphenyl group and one sterically and electronically variable N‐aryl group, have been used to prepare the N,N′‐nickel (II) halide complexes, [1‐[2,4‐{(C15H13}2–6‐MeC6H2N]‐2‐(ArN)C2C10H6]NiX2 (X = Br: Ar = 2,6‐Me2C6H3 Ni1 , 2,6‐Et2C6H3 Ni2 , 2,6‐i‐Pr2C6H3 Ni3 , 2,4,6‐Me3C6H2 Ni4 , 2,6‐Et2–4‐MeC6H2 Ni5 ) and (X = Cl: Ar = 2,6‐Me2C6H3 Ni6 , 2,6‐Et2C6H3 Ni7 , 2,6‐i‐Pr2C6H3 Ni8 , 2,4,6‐Me3C6H2 Ni9 , 2,6‐Et2–4‐MeC6H2 Ni10 ), in high yield. The molecular structures Ni3 and Ni7 highlight the extensive steric protection imparted by the ortho‐dibenzocycloheptyl group and the distorted tetrahedral geometry conferred to the nickel center. On activation with either Et2AlCl or MAO, Ni1 – Ni10 exhibited very high activities for ethylene polymerization with the least bulky Ni1 the most active (up to 1.06 × 107 g PE mol?1(Ni) h?1 with MAO). Notably, these sterically bulky catalysts have a propensity towards generating very high molecular weight polyethylene with moderate levels of branching and narrow dispersities with the most hindered Ni3 and Ni8 affording ultra‐high molecular weight material (up to 1.5 × 106 g mol?1). Indeed, both the activity and molecular weights of the resulting polyethylene are among the highest to be reported for this class of unsymmetrical 1,2‐bis (imino)acenaphthene‐nickel catalyst. 相似文献
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Oussama Dehbi Esam A. Ishak Mohammed A. Bakht Mohammed H. Geesi Mohammed B. Alshammari Vincent Chagnault 《Green Chemistry Letters and Reviews》2018,11(2):62-66
An efficient and ecofriendly method for the synthesis of disubstituted 5-aminopyrimidines from vinyl azides and urea or thiourea was developed. This reaction proceeds under microwave irradiation conditions in the presence of water as a solvent. The remarkable features of this new protocol are high conversion, short reaction times, cleaner reaction profiles and straightforward procedure. 相似文献