In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-l...In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-linking reaction was studied.The O-containing functional groups change the weight loss and H_2O,CO_2,CO yields of bituminous coal before and after[H0Emim][BF_4]and[Amim]Cl pre-treatment and were detected by Fourier Transform Infrared spectroscopy(FT1R) and Thermo Gravimetric(TC) analysis.The results show that | AmimjCI has a weaker ability to inhibit the cross-linking reaction of bituminous coal compared to[HOEmim][BF_4].Besides,based on Quantum Chemistry calculation,it was found that the different inhibiting effects of |H0Emim][BF_4]and[Amim]Cl are greatly related to their anions and the H linked with C2 atom on the imidazole ring.The H-donor ability of coal will be enhanced by[HOEmim][BF_4]leading to a weaker cross-linking reaction of coal.展开更多
CdS quantum dots(QDs) sensitized TiO2 nanotube arrays photoelectrodes were investigated for their photovoltaic performance of quantum dots-sensitized solar cells. The highly ordered TiO2 nanotube arrays(TNAs) were...CdS quantum dots(QDs) sensitized TiO2 nanotube arrays photoelectrodes were investigated for their photovoltaic performance of quantum dots-sensitized solar cells. The highly ordered TiO2 nanotube arrays(TNAs) were synthesized on Ti foils by anodic oxidation method. Then CdS quantum dots were deposited onto the TiO2 nanotube arrays by successive ionic layer absorption and reaction(SILAR) method to serve as the sensitizers. Cd(NO3)2 and Na2S were used as the precursor materials of Cd+ and S2- ions, respectively. It is found that the CdS QDs sensitizer may significantly increase the light response of TiO2 nanotube arrays. With increasing CdS QDs deposition cycles, the visible light response increases. Maximum photocurrent was obtained for the QDs that have an absorption peak at about 500 nm. Under AM 1.5 G illuminations(100 mW cm^-2), a 4.85 mA/cm^2 short circuit current density was achieved, and the maximium energy conversion efficiency of the asprepared CdS QDs-sensitized TNAs solar cells was obtained as high as 0.81% at five SILAR cycles.展开更多
12-Aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives were synthesized by a convenient and environmentally benign procedure involving multicomponent condensation reactions of substituted aromatic aldehydes w...12-Aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives were synthesized by a convenient and environmentally benign procedure involving multicomponent condensation reactions of substituted aromatic aldehydes with 2,7-dihydroxynaphthalene/2-naphthols/2,6-dihydroxynaphthlene and cyclic 1,3-dicarbonyl compounds in task specific acidic ionic liquid[NMP]HPOat 80 ℃.This protocol has proved to be efficient in terms of good yields,operational simplicity,easy workup,recyclability of reaction medium/catalyst,and short reaction time.展开更多
An effcient method for the synthesis of imidazole derivatives by a three-component condensation of benzil or 9,10-phenanthrenequinone,aldehydes and ammonium acetate using supported ionic liquidlike phase(SILLP)catal...An effcient method for the synthesis of imidazole derivatives by a three-component condensation of benzil or 9,10-phenanthrenequinone,aldehydes and ammonium acetate using supported ionic liquidlike phase(SILLP)catalyst under ultrasonic irradiation or classical heating conditions is reported.The present methodology offers several advantages,such as excellent yields,simple procedures,short reaction times,simple work-up and mild conditions.The catalyst is easily separated from the products by fltration and also exhibits remarkable reusable activity.These highly substituted imidazoles were also evaluated for their anti-microbial activity.展开更多
Caffeine was applied as a green and natural catalyst for the one-pot,four-component sequential condensation between 2-hydroxy-1,4-naphthoquinone,aromatic 1,2-diamines,ammonium thiocyanate and acid chlorides in the pre...Caffeine was applied as a green and natural catalyst for the one-pot,four-component sequential condensation between 2-hydroxy-1,4-naphthoquinone,aromatic 1,2-diamines,ammonium thiocyanate and acid chlorides in the presence of a basic ionic liquid(l-butyl-3-methylimidazolium hydroxide) to afford the corresponding benzo[a][1,3]oxazino[6,5-c]phenazine derivatives.In this one-pot transformation,five bonds and two new rings are efficiently formed.This protocol has the advantages of operational simplicity,high yields,easy workup,avoidance of hazardous or toxic catalysts and organic solvents and high chemo-and regioselectivities.展开更多
Semiconductor sensitized solar cells(SSSCs) are promising candidates for the third generation of cost-effective photovoltaic solar cells and it is important to develop a group of robust, environment-friendly and visib...Semiconductor sensitized solar cells(SSSCs) are promising candidates for the third generation of cost-effective photovoltaic solar cells and it is important to develop a group of robust, environment-friendly and visible-light-responsive semiconductor sensitizers. In this paper, we first synthesized bismuth vanadate(Bi VO4) quantum dots by employing facile successive ionic layer adsorption and reaction(SILAR) deposition technique, which we then used as a sensitizer for solar energy conversion. The preliminary optimised oxide SSSC showed an efficiency of 0.36%, nearly 2 orders of magnitude enhancement compared with bare Ti O2, due to the narrow bandgap absorption of Bi VO4 quantum dots and intimate contact with the oxide substrate. This result not only demonstrates a simple method to prepare Bi VO4 quantum dots based solar cells, but also provides important insights into the low bandgap oxide SSSCs.展开更多
Nanostructured ot-Fe2O3 were prepared by precipitation followed by calcination method. Cetyltrimethylammonium bromide (CRAB) was used as surfactant. The nano α-Fe2O3 was then silanized with (3-chloropropyl)-triet...Nanostructured ot-Fe2O3 were prepared by precipitation followed by calcination method. Cetyltrimethylammonium bromide (CRAB) was used as surfactant. The nano α-Fe2O3 was then silanized with (3-chloropropyl)-triethoxysilane (CPTES) by room temperature mixing ofα-Fe2O3 and CPTES to produce silane coated ct-Fe2O3 (CIPr-Si@Fe2O3). As-synthesized CIPr-Si@Fe2O3 was functionalized via covalent grafting of benzimidazole to produce 3-(1-benzimidazole)Pr-Si@Fe2O3. This was further reacted with bromine to afford α-Fe2O3 immobilized benzimidazolium tribromide (α-Fe2O3-BIM tribromide). This ionic liquid (IL) α-Fe2O3 BIM tribromide was characterized by FT-IR, XRD, TEM, SEM, TGA, VSM, EDX and BET analysis. The as-synthesized IL tribromide was used as catalyst for one-pot synthesis of highly substituted piperidines. The method is greener in terms of solvent selection, recovery of the catalyst and efficiency.展开更多
基金the support from the National Natural Science Foundation of China(Nos.51304073and 51304071)the Educational Commission of Henan Province(Nos.13A440324 and 12B440004)+1 种基金the Open Projects of State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(No.12KF02)Henan Polytechnic University(Nos.B2012-068 and B2012-085)
文摘In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-linking reaction was studied.The O-containing functional groups change the weight loss and H_2O,CO_2,CO yields of bituminous coal before and after[H0Emim][BF_4]and[Amim]Cl pre-treatment and were detected by Fourier Transform Infrared spectroscopy(FT1R) and Thermo Gravimetric(TC) analysis.The results show that | AmimjCI has a weaker ability to inhibit the cross-linking reaction of bituminous coal compared to[HOEmim][BF_4].Besides,based on Quantum Chemistry calculation,it was found that the different inhibiting effects of |H0Emim][BF_4]and[Amim]Cl are greatly related to their anions and the H linked with C2 atom on the imidazole ring.The H-donor ability of coal will be enhanced by[HOEmim][BF_4]leading to a weaker cross-linking reaction of coal.
基金Funded by Major State Basic Research Development Program of China (973 Program) (No.2009CB939704)Key Project of Chinese Ministry of Education (No.309021)
文摘CdS quantum dots(QDs) sensitized TiO2 nanotube arrays photoelectrodes were investigated for their photovoltaic performance of quantum dots-sensitized solar cells. The highly ordered TiO2 nanotube arrays(TNAs) were synthesized on Ti foils by anodic oxidation method. Then CdS quantum dots were deposited onto the TiO2 nanotube arrays by successive ionic layer absorption and reaction(SILAR) method to serve as the sensitizers. Cd(NO3)2 and Na2S were used as the precursor materials of Cd+ and S2- ions, respectively. It is found that the CdS QDs sensitizer may significantly increase the light response of TiO2 nanotube arrays. With increasing CdS QDs deposition cycles, the visible light response increases. Maximum photocurrent was obtained for the QDs that have an absorption peak at about 500 nm. Under AM 1.5 G illuminations(100 mW cm^-2), a 4.85 mA/cm^2 short circuit current density was achieved, and the maximium energy conversion efficiency of the asprepared CdS QDs-sensitized TNAs solar cells was obtained as high as 0.81% at five SILAR cycles.
基金UGC,New Delhi,India for the grant of Junior and Senior Research FellowshipUGC,New Delhi,India for the grant of Junior Research Fellowship
文摘12-Aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives were synthesized by a convenient and environmentally benign procedure involving multicomponent condensation reactions of substituted aromatic aldehydes with 2,7-dihydroxynaphthalene/2-naphthols/2,6-dihydroxynaphthlene and cyclic 1,3-dicarbonyl compounds in task specific acidic ionic liquid[NMP]HPOat 80 ℃.This protocol has proved to be efficient in terms of good yields,operational simplicity,easy workup,recyclability of reaction medium/catalyst,and short reaction time.
基金the Research Council of University of Guilan for the financial support
文摘An effcient method for the synthesis of imidazole derivatives by a three-component condensation of benzil or 9,10-phenanthrenequinone,aldehydes and ammonium acetate using supported ionic liquidlike phase(SILLP)catalyst under ultrasonic irradiation or classical heating conditions is reported.The present methodology offers several advantages,such as excellent yields,simple procedures,short reaction times,simple work-up and mild conditions.The catalyst is easily separated from the products by fltration and also exhibits remarkable reusable activity.These highly substituted imidazoles were also evaluated for their anti-microbial activity.
基金financial support from the Research Council of Young Researchers and Elite Club,Yazd Branch,Islamic Azad University,Yazd,Iran and University of Science and Arts of Yazd,Iran
文摘Caffeine was applied as a green and natural catalyst for the one-pot,four-component sequential condensation between 2-hydroxy-1,4-naphthoquinone,aromatic 1,2-diamines,ammonium thiocyanate and acid chlorides in the presence of a basic ionic liquid(l-butyl-3-methylimidazolium hydroxide) to afford the corresponding benzo[a][1,3]oxazino[6,5-c]phenazine derivatives.In this one-pot transformation,five bonds and two new rings are efficiently formed.This protocol has the advantages of operational simplicity,high yields,easy workup,avoidance of hazardous or toxic catalysts and organic solvents and high chemo-and regioselectivities.
基金supported by the National Basic Research Program of China(2011CBA00700)the National High Technology Research and Development Program of China(2011AA050527)the National Natural Science Foundation of China(21403247,21173228,21103197)
文摘Semiconductor sensitized solar cells(SSSCs) are promising candidates for the third generation of cost-effective photovoltaic solar cells and it is important to develop a group of robust, environment-friendly and visible-light-responsive semiconductor sensitizers. In this paper, we first synthesized bismuth vanadate(Bi VO4) quantum dots by employing facile successive ionic layer adsorption and reaction(SILAR) deposition technique, which we then used as a sensitizer for solar energy conversion. The preliminary optimised oxide SSSC showed an efficiency of 0.36%, nearly 2 orders of magnitude enhancement compared with bare Ti O2, due to the narrow bandgap absorption of Bi VO4 quantum dots and intimate contact with the oxide substrate. This result not only demonstrates a simple method to prepare Bi VO4 quantum dots based solar cells, but also provides important insights into the low bandgap oxide SSSCs.
文摘Nanostructured ot-Fe2O3 were prepared by precipitation followed by calcination method. Cetyltrimethylammonium bromide (CRAB) was used as surfactant. The nano α-Fe2O3 was then silanized with (3-chloropropyl)-triethoxysilane (CPTES) by room temperature mixing ofα-Fe2O3 and CPTES to produce silane coated ct-Fe2O3 (CIPr-Si@Fe2O3). As-synthesized CIPr-Si@Fe2O3 was functionalized via covalent grafting of benzimidazole to produce 3-(1-benzimidazole)Pr-Si@Fe2O3. This was further reacted with bromine to afford α-Fe2O3 immobilized benzimidazolium tribromide (α-Fe2O3-BIM tribromide). This ionic liquid (IL) α-Fe2O3 BIM tribromide was characterized by FT-IR, XRD, TEM, SEM, TGA, VSM, EDX and BET analysis. The as-synthesized IL tribromide was used as catalyst for one-pot synthesis of highly substituted piperidines. The method is greener in terms of solvent selection, recovery of the catalyst and efficiency.