Cyclopentadienyl ruthenium complexes with tricarbollide ligands

2010 ◽  
Vol 75 (11) ◽  
pp. 1139-1148 ◽  
Author(s):  
Dmitry S. Perekalin ◽  
Evgeniya A. Trifonova ◽  
Ivan V. Glukhov ◽  
Josef Holub ◽  
Alexander R. Kudinov

Reaction of the tricarbollide anion [7,8,9-C3B8H11]– (1a) with the naphthalene complex [CpRu(C10H8)]+ under visible light irradiation in CH2Cl2 gives the 12-vertex closo-ruthenacarborane 1-Cp-1,2,3,5-RuC3B8H11 (2; 87% yield). This complex was also obtained by reaction of 1a with CpRu(cod)Cl (97%). Upon heating at 80 °C in toluene 2 rearranges into isomer 1-Cp-1,2,4,10-RuC3B8H11 (3; 63%). Irradiation of 1a with [CpRu(C10H8)]+ in acetone gives the 11-vertex closo-1-Cp-1,2,3,4-RuC3B7H10 (4; 32%). The latter was also prepared by reaction of 1a with [CpRu(MeCN)3]+ (59%). Compound 2 slowly undergoes cage contraction in acetone giving 4. Irradiation of 1a with [Cp*Ru(C10H8)]+ affords the isomeric 12-vertex closo-ruthenacarboranes 1-Cp*-1,2,3,5-RuC3B8H11 and 1-Cp*-1,2,4,10-RuC3B8H11 (2.2:1 ratio; 56%). Reaction of the amino-substituted tricarbollide anion [7-tBuNH-7,8,9-C3B8H10]– with [(C5R5)Ru(C10H8)]+ (R = H, Me) selectively gives 12-vertex closo-ruthenacarboranes 1-(C5R5)-12-tBuNH-1,2,4,12-RuC3B8H10 (ca. 50%). The structures of 2 and 4 were confirmed by X-ray diffraction.

2014 ◽  
Vol 787 ◽  
pp. 35-40 ◽  
Author(s):  
Xiao Yan Zhou ◽  
Peng Wei Zhou ◽  
Hao Guo ◽  
Bo Yang ◽  
Ru Fei Ren

The p-n junction photocatalysts, p-CuO (at. 0-25%)/n-ZnO nanocomposite were prepared through hydrothermal method without using any organic solvent or surfactant. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-Ray spectroscopy, and UV-vis spectroscopy. The results demonstrated that the CuO/ZnO nanocomposite presented a two-dimensional morphology composed of sheet-like ZnO nanostructures adorned with CuO nanoparticles. The photocatalytic activity of CuO/ZnO with different Cu/Zn molar rations and pure ZnO synthesized by the identical synthetic route were evaluated by degrading methylene blue (MB) dye under UV-visible light irradiation. The CuO/ZnO with Cu/Zn molar ratio of 4% exhibits the highest photocatalytic activity compared that of the other photocatalysts under the identical conditions. It is mainly attributed to the increased charge separation rate in the nanocomposite and the extended photo-responding range.


2021 ◽  
Vol 1035 ◽  
pp. 1043-1049
Author(s):  
Di Xiang ◽  
Chang Long Shao

A simple route has been developed for the synthesis of Ag2O/ZnO heterostructures and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectroscopy analysis. Considering the porous structure of Ag2O/ZnO, the photocatalytic degradation for the organic dyes, such as eosin red (ER), methyl orange (MO), methylene blue (MB) and rhodamine B (RhB), under visible light irradiation was investigated in detail. Noticeably, Ag2O/ZnO just took 40 min to degrade 96 % MB. The rate of degradation using the Ag2O/ZnO heterostructures was 2.3 times faster than that of the bare porous ZnO nanospheres under visible light irradiation due to that the recombination of the photogenerated charge was inhibited greatly in the p-type Ag2O and n-type ZnO semiconductor. So the Ag2O/ZnO heterostuctures showed the potential application on environmental remediation.


2011 ◽  
Vol 364 ◽  
pp. 238-242 ◽  
Author(s):  
Kimi Melody ◽  
Yuliati Leny ◽  
Mustaffa Shamsuddin

A series of In0.1SnxZn0.85-2xS solid solutions was synthesized by hydrothermal method and employed as photocatalyst for photocatalytic hydrogen evolution under visible light irradiation. The structures, optical properties and morphologies of the solid solutions were studied by X-ray diffraction, diffuse reflectance UV–visible spectroscopy and field emission scanning electron microscopy. From the characterizations, it was confirmed that In0.1SnxZn0.85-2xS solid solution can be obtained and they have nanosized particles. The highest photocatalytic activity was observed on In0.1Sn0.03Zn0.79S photocatalyst, with average rate of hydrogen production 3.05 mmol/h, which was 1.2 times higher than the In0.1Zn0.85S photocatalyst.


2019 ◽  
Vol 12 (06) ◽  
pp. 1950085 ◽  
Author(s):  
Di Zhao ◽  
Xuezheng An ◽  
Yaxian Sun ◽  
Guihua Li ◽  
Hongyan Liu ◽  
...  

p-n heterojunction Ag2CO3/Ag3PO4/Ni thin films were prepared by electrochemical co-deposition. The surface morphology and structural properties of the thin films were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic (PC) properties of the Ag2CO3/Ag3PO4/Ni composite thin films were investigated by their ability to degrade rhodamine B (RhB) and Congo red (CR) under visible light irradiation. The results showed that the photodegradation efficiency of RhB by an Ag2CO3/Ag3PO4/Ni thin film under visible-light irradiation for 30[Formula: see text]min (98.84%) was 2.64 times higher than that of an Ag3PO4/Ni thin film and 3.44 times higher than of an Ag2CO3/Ni thin film. The presence of a [Formula: see text]-[Formula: see text] heterojunction greatly increased the charge conductivity of the film and its ability to photocatalytically reduce dissolved oxygen, which are the main reasons for the improved PC performance of the Ag2CO3/Ag3PO4/Ni films.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Shaukat Ali Shahid ◽  
Ayman Nafady ◽  
Inam Ullah ◽  
Yun H. Taufiq-Yap ◽  
Imran Shakir ◽  
...  

High functional ZrFe2O5nanoparticles were synthesized using coprecipitation technique. The chemical composition of nanomaterials was studied by energy-dispersive X-ray (EDX). To observe the morphology, field emission scanning electron microscopy (FE-SEM) was used. X-ray diffraction (XRD) technique was utilized to appraise the structure of the synthesized material. The photocatalytic behavior of ZrFe2O5nano-particles was investigated by measuring the degradation rate of toluidine blue O (TBO) dye in aqueous solution in the presence of ZrFe2O5nano-particles under visible light irradiation. A steady decrease in absorption peak under visible light irradiation was observed by increasing exposure time. The degradation efficiency was observed as 92% after 140 min of exposure to visible light. Besides, ZrFe2O5nanophotocatalyst could be recovered and recycled easily. The rate of TBO and total organic carbon (TOC) removal under visible light irradiation decreased by only 5% and 10%, respectively, after seven cycles of use, demonstrating the high photostability of the synthesized nano-photocatalyst material.


2009 ◽  
Vol 79-82 ◽  
pp. 2115-2118
Author(s):  
Xian Hua Zhang ◽  
Lei Ge

The novel visible-light-driven Ag/BiVO4 composite photocatalysts were successfully prepared by photo-deposition method. The as-prepared Ag/BiVO4 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities of the Ag/BiVO4 powders were determined by degradation of methyl orange molecules in water under visible light irradiation (λ>400nm). The photocatalytic experiments indicated that the composite samples enhanced photo-activity under visible light irradiation.


2014 ◽  
Vol 807 ◽  
pp. 101-113 ◽  
Author(s):  
J. Theerthagiri ◽  
R.A. Senthil ◽  
J. Madhavan ◽  
B. Neppolian

The graphitic carbon nitride (g-C3N4) materials have been synthesized from nitrogen rich precursors such as urea and thiourea by directly heating at 520 °C for 2 h. The as-synthesized carbon nitride samples were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) and particle size analysis. The photoelectrochemical measurements were performed using several on-off cycles under visible-light irradiation. The x-ray diffraction peak is broader which indicates the fine powder nature of the synthesized materials. The estimated crystallite size of carbon nitrides synthesized from urea (U-CN) and thiourea (T-CN) are 4.0 and 4.4 nm respectively. The particle size of U-CN and T-CN were analysed by particle size analyser and were found to be 57.3 and 273.3 nm respectively. The photocatalytic activity for the degradation of the textile dye namely, direct red-81 (DR81) using these carbon nitrides were carried out under visible light irradiation. In the present investigation, a comparison study on the carbon nitrides synthesized from cheap precursors such as urea and thiourea for the degradation of DR81 has been carried out. The results inferred that U-CN exhibited higher photocatalytic activity than T-CN. The photoelectrochemical studies confirmed that the (e--h+) charge carrier separation is more efficient in U-CN than that of T-CN and therefore showed high photocatalytic degradation. Further, the smaller particle size of U-CN is also responsible for the observed degradation trend.


2013 ◽  
Vol 815 ◽  
pp. 567-573
Author(s):  
Xiao Pei Zhang ◽  
Yue Lin Wei ◽  
Shu Hong Chen ◽  
Jing Xu ◽  
Huang Zhao ◽  
...  

A novel and highly efficient photocatalyst, Eosin Y-sensitized Pt-intercalated nanotube Pt/HLa Nb2O7, was found to be very active for hydrogen generation within triethanolamine (TEOA) solution as the electron donor under visible-light irradiation (λ420 nm). The photocatalysts were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), scan electron microscope (SEM) and energy dispersive spectrometer (EDS). The results showed that the significant enhancement of photocatalytic activity was achieved via Pt intercalating and subsequent dye sensitization of Pt/HLaNb2O7. The highest rate for hydrogen evolution was 4.45 mmol·g-1·h-1under irradiation with a wavelength longer than 420 nm, and the probable mechanism of photosensitized hydrogen evolution have also been discussed.


2016 ◽  
Vol 35 (9) ◽  
pp. 853-856 ◽  
Author(s):  
Yi Shen ◽  
Xiaomin Wang ◽  
Guifu Zuo ◽  
Fengfeng Li ◽  
Yanzhi Meng

AbstractMonoclinic BiVO4 photocatalyst was successfully synthesized by hydrothermal method under appropriate temperature. The photocatalytic performance of BiVO4 was improved by calcining at appropriate temperature. The structural and morphological properties of the synthesized BiVO4 photocatalysts were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It is confirmed that the photocatalytic activity of the prepared catalysts was evaluated by the photodegradation of RhB under visible-light irradiation. BiVO4 calcined under appropriate temperature exhibited higher photocatalytic activity than uncalcined BiVO4 under visible light irradiation because calcination might effectively increases the purity of monoclinic bismuth vanadate.


2022 ◽  
Author(s):  
G. Roshini ◽  
V. Sathish ◽  
S. Manigandan ◽  
A. Tamilarasi ◽  
E. Priyanka

Abstract In this paper, the highly stable Ag/CdS-WO2 nanocomposite was fabricated by a facile and capping agent-free hydrothermal technique. The fabricated Ag doped CdS-WO2 nanocomposite were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and UV-vis diffuse reflectance (DRS) spectroscopy. The photocatalytic performance of synthesized photocatalysts was evaluated for the photodegradation of rhodamine B (Rh B) under visible light irradiation (VLI). The parameters used for the optimization of the photocatalyst were pH, catalyst dose, oxidant dose, and irradiation time. Based on this, a possible reaction mechanism for the enhancement of photocatalytic activity of Ag/CdS-WO2 has been proposed. Hence, we have a tendency to believe it might be a promising material that may be used for the photodegradation of organic pollutants present in wastewater.


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