Controllable Synthesis of Enhanced Visible Light Responded Fe, N, Co Tri-TiO2@MCM-41 Nanocomposites and Its Photocatalytic Performance

2021 ◽  
Vol 21 (10) ◽  
pp. 5107-5119
Author(s):  
Yanhui Niu ◽  
Guanyu Liu ◽  
Huiyun Xia ◽  
Xu Zhao ◽  
Gengtong Zhang ◽  
...  

A novel method for in situ synthesis of Fe, N, Co tri-TiO2 (DT) loading on MCM-41 composite photocatalyst was proposed. Fe, N, Co tri-TiO2@MCM-41 (DTM) with adsorption-degradation synergy was prepared by adjusting tetrabutyl titanate (TBOT) concentrations, the alcohol-water ratio in the atmosphere of the reaction chamber. The influence of preparation parameters on the texture structure, catalytic activity, and the synergism of adsorption and degradation of the DTM was discussed, the optimal parameters were determined. The DTM was characterized by XRD, TEM, BET, FT-IR, and UV-Vis. Besides, the DTM exhibited obvious redshift and visible catalytic activity compared with undoped TiO2@MCM-41 (TM), which possessed excellent performance in the degradation of gaseous and liquid pollutants. The degradation rate of methylene blue (MB) and nitric oxide (NO) was 96.39% and 56.75%, respectively. Furthermore, DTM photocatalyst exhibited excellent reusability. The degradation efficiency of MB and NO after five cycles decreased by 4.54% and 5.89%, respectively.

Author(s):  
Pham Tung Son ◽  
Le Ha Giang ◽  
Nguyen Ba Manh ◽  
Pham Thi Thu Trang ◽  
Vu Quang Loi ◽  
...  

A zirconium catalyst system supported on MCM-41 (S-Z) with various weight components (4-20 wt.%) Was synthesized by the sol-gel method. Structure and Morphology Catalysts were characterized by X-RD, TEM, BET, FT-IR and TPD-NH3 methods. In this catalyst, ZrO2 is highly dispersed on the surface of MCM-41 capillaries. Catalytic activity and selectivity were evaluated by the effectiveness of mild hydrothermal decomposition of cellulose to 5-hydroxymethyl furfural (5-HMF). The results show that a catalyst with medium acidity exhibits a high selectivity of 5-HMF. Keywords: S-Zr/MCM-41 materials, sol-gel methods, cellulose, 5-HMF.


2011 ◽  
Vol 233-235 ◽  
pp. 234-237 ◽  
Author(s):  
Sa Liu ◽  
Jian Wei Guo ◽  
Chu Fen Yang ◽  
Long Huan Li ◽  
Yi Hua Cui

Al-containing mesoporous molecular sieves(Al-MCM-41) were synthesized at ambient temperature. The structures of samples were characterized by XRD, N2-adsorption/desorption isotherms and FT-IR, etc. The evaluation results showed that Al-MCM-41 had higher catalytic activity for isomerization conversion of endo-tetrahydrodicyclo-pentadiene (endo-TCD) into exo-tetrahydrodicyclo-pentadiene (exo-TCD) and adamantane (AdH). Loading inorganic acid on the surface of Al-MCM-41 led increase of its catalytic activity and the yield of adamantane.


2021 ◽  
Vol 18 ◽  
Author(s):  
Mohammad Nikpassand ◽  
Leila Zare Fekri ◽  
Afshin Pourahmad ◽  
Zeinab Jafarian

Introduction: In this study, the synthesis of azo-linked acridine by the reaction of dimedone and synthesized diazoaryl-(2-amino-5-(phenyl)methanone using Ag2S/RHA-MCM-41nanocomposite is reported. Materials and Methods: The synthesized catalyst was characterized by FT-IR, XRD, and SEM. According to the obtained results, Ag2S/RHA-MCM-41 nanocomposite exhibited high activity in the synthesis of azo-acridine derivatives based on desirable yields and reaction time. Products were prepared in 1.5-2 h and with 88-93% yield. In all the reactions, the catalyst could be easily removed and reused, and its catalytic activity was maintained after five uses and did not decrease significantly. The structures of all newly synthesized products were characterized by spectroscopic spectra (FT-IR, 1H NMR, 13C NMR) and elemental analyses. Results and Discussion: The results of the study showed that ionic liquid [DBU]OAc (entry 8) and MCM-41/Ag2S-RHA nanocomposite (entry 8) possessed better efficiency and shorter time than other reaction conditions. Conclusion: In this study, new azo-linked acridine derivatives were synthesized by the reaction of different azo derivatives and dimedone using MCM-41/Ag2S-RHA nanocomposite, and the reaction products were obtained in 1.5-2 h with an efficiency of 88-93%. The short reaction time and high efficiency of the obtained products indicated the high efficiency of this method. In all the reactions, MCM-41/Ag2S-RHA nanocomposite could be easily removed and reused. Its catalytic activity was maintained in the sample reaction after five runs and did not decrease significantly.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fereshte Hassanzadeh-Afruzi ◽  
Somayeh Asgharnasl ◽  
Sara Mehraeen ◽  
Zeinab Amiri-Khamakani ◽  
Ali Maleki

AbstractIn this study, a novel mesoporous nanocomposite was fabricated in several steps. In this regard, SBA-15 was prepared by the hydrothermal method, next it was magnetized by in-situ preparation of Fe3O4 MNPs. After that, the as-prepared SBA-15/Fe3O4 functionalized with 3-minopropyltriethoxysilane (APTES) via post-synthesis approach. Then, the guanidinylated SBA-15/Fe3O4 was obtained by nucleophilic addition of APTES@SBA-15/Fe3O4 to cyanimide. The prepared nanocomposite exhibited excellent catalytic activity in the synthesis of dihydropyrano[2,3-c]pyrazole derivatives which can be related to its physicochemical features such as strong basic sites (presented in guanidine group), Lewis acid site (presented in Fe3O4), high porous structure, and high surface area. The characterization of the prepared mesoporous nanocomposite was well accomplished by different techniques such as FT-IR, EDX, FESEM, TEM, VSM, TGA, XRD and BET. Furthermore, the magnetic catalyst was reused at least six consequent runs without considerable reduction in its catalytic activity.


2007 ◽  
Vol 124-126 ◽  
pp. 1793-1796 ◽  
Author(s):  
Gun Dae Lee ◽  
Sung Gab Kim ◽  
Hee Hoon Jeong ◽  
Seong Soo Park ◽  
Seong Soo Hong

The photo-catalytic hydroxylation of phenol with hydrogen peroxide was carried out over TS-1 and Ti-MCM-41 catalysts. For comparison, the dark (thermal)-catalytic hydroxylation of phenol was also performed. The difference in catalytic behaviors of TS-1 and Ti-MCM-41 and product distribution in both the reactions were investigated. The TS-1 and Ti-MCM-41 catalysts having the Si/Ti ratio of 50 were prepared by in-situ crystallization and characterized using XRD, UV-DRS. In the all reactions, the main products were catechol (CAT), hydroquinone (HQ) and benzoquinone (BQ). In dark (thermal)-reaction, TS-1 showed a higher catalytic activity than Ti- MCM-41. In photo-reaction, however, the activity of Ti-MCM-41 was comparable to that of TS-1. The conversion of phenol and the selectivity to CAT in the photo-catalytic reaction were higher than those in dark (thermal)-reaction. In the all reactions, the selectivity to CAT increased remarkably when the selectivities to HQ and BQ decreased with reaction time.


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