Synthesis of novel zinc porphyrins and their photocatalytic activity

2018 ◽  
Vol 47 (4) ◽  
pp. 360-366 ◽  
Author(s):  
Shao Rui Chen

Purpose The purpose of this study is to investigate the effect of the spacer length of zinc porphyrin-TiO2 hybrids by photodegradation of methyl orange (MO) in aqueous solution under visible light. Design/methodology/approach 5-Mono-[4-hydroxyphenyl]-10,15,20-triphenylporphyrin was synthesized using Alder method. A new series of porphyrins and their corresponding zinc complexes (ZnPp) were obtained from 5-mono-[4-hydroxyphenyl]-10,15,20-triphenylporphyrin via nucleophilic substitution reaction. The ZnPp-TiO2 photocatalysts were prepared by loading ZnPp onto TiO2 and characterized by scanning electron microscope, X-ray diffraction, UV-vis diffuse reflectance spectrum and X-ray photoelectron spectroscopy. Findings The results indicated that zinc porphyrins were successfully loaded on the surface of TiO2 microsphere, which is crucial to enhance the activity of the catalytic composite under visible light. All the novel photocatalysts showed much enhanced photoactivity than bare TiO2. Among all the prepared ZnPp-TiO2, 5,10,15-triphenyl-20-[4-(4-naphthoxy)-butoxy]phenyl zinc porphyrin-TiO2 (4b) showed the highest photocatalytic activity for the degradation of MO. Research limitations/implications Synthesis of these zinc porphyrins had never been reported previously. Originality/value Four novel zinc porphyrin-TiO2 photocatalysts which could response to visible light in degradation of MO were synthesized using Alder method. The results show that the photocatalytic activity of 5,10,15-triphenyl-20-[4-(4-naphthoxy)butoxy] phenyl zinc porphyrin- TiO2 is higher than others.

2013 ◽  
Vol 860-863 ◽  
pp. 907-910
Author(s):  
Xiao Xia Lin ◽  
Jia Liu ◽  
De Gang Fu

B-doped TiO2nanotube arrays (B-TNTs) were synthesized by anodization method combined with dip-calcination technique. The physicochemical properties and surface morphology were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectrum (DRS). Methyl blue (MB) solution was utilized as the degradation model to evaluate the photocatalytic activity of B-TNTs under visible light irradiation. The results show B-TNTs shifts the absorption edge of TiO2nanotube arrays to the visible light region and B-TNTs displays higher photocatalytic activity compared with undoped TNTs.


2011 ◽  
Vol 383-390 ◽  
pp. 3188-3191
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang ◽  
Hai Peng Huang

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1671 ◽  
Author(s):  
Weike Zhang ◽  
Yanrong Zhang ◽  
Kai Yang ◽  
Yanqing Yang ◽  
Jia Jia ◽  
...  

A silicon dioxide/carbon nano onions/titanium dioxide (SiO2/CNOs/TiO2) composite was synthesized by a simple sol-gel method and characterized by the methods of X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analysis (TG), differential scanning calorimeter (DSC) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). In this work, the photocatalytic activity of the SiO2/CNOs/TiO2 photocatalyst was assessed by testing the degradation rate of Rhodamine B (RhB) under visible light. The results indicated that the samples exhibited the best photocatalytic activity when the composite consisted of 3% CNOs and the optimum dosage of SiO2/CNOs/TiO2(3%) was 1.5 g/L as evidenced by the highest RhB degradation rate (96%). The SiO2/CNOs/TiO2 composite greatly improved the quantum efficiency of TiO2. This work provides a new option for the modification of subsequent nanocomposite oxide nanoparticles.


2021 ◽  
Author(s):  
Yu Fan ◽  
Yan-ning Yang ◽  
Chen Ding

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Qianzhi Xu ◽  
Xiuying Wang ◽  
Xiaoli Dong ◽  
Chun Ma ◽  
Xiufang Zhang ◽  
...  

S/Zn codoped TiO2nanomaterials were synthesized by a sol-gel method. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the morphology, structure, and optical properties of the prepared samples. The introduction of Zn and S resulted in significant red shift of absorption edge for TiO2-based nanomaterials. The photocatalytic activity was evaluated by degrading reactive brilliant red X-3B solution under simulated sunlight irradiation. The results showed S/Zn codoped TiO2exhibited higher photocatalytic activity than pure TiO2and commercial P25, due to the photosynergistic effect of obvious visible light absorption, efficient separation of photoinduced charge carriers, and large surface area. Moreover, the content of Zn and S in the composites played important roles in photocatalytic activity of TiO2-based nanomaterials.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongpo Zhou ◽  
Haiying Wang

TheFe + Ncodoped nanowire samples are prepared by hydro-thermal method and annealed in NH3atmosphere. The XRD (X-ray diffraction), SEM (Scanning electron microscope), UV-vis absorption spectroscopy, and BET (Brunauer, Emmett, and Teller) results indicate that the samples are pure anatase nanowires. TheFe + Ncodoped samples have the highest specific surface area, the largest red-shift, and the largest absorption enhancement in the visible light range compared with Fe doped, N doped, and undoped nanowires. The measurements of XPS (X-ray photoelectron spectroscopy) show that N content ofFe + Ncodoped TiO2is about two times as large as that of the N doped TiO2. It is assumed that nitrogen doping plays a very important role for the photocatalytic activity increase and hence theFe + Ncodoped nanowire TiO2shows the most effective photocatalytic activity under the visible light irradiation.


2019 ◽  
Vol 889 ◽  
pp. 43-50 ◽  
Author(s):  
Tran Doan An ◽  
Nguyen Van Phuc ◽  
Nguyen Ngoc Tri ◽  
Huynh Thi Phu ◽  
Nguyen Phi Hung ◽  
...  

The S-doped g-C3N4materials were prepared by heating mixtures of urea and thiourea with various weight ratios at 550 °C, and denoted as x:y SCN, where x:y is weight ratios of urea to thiourea. The obtained samples were characterized by X-ray diffraction, diffuse reflectance ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric differential thermal analysis, scanning electron microscopy and infrared spectra. The results showed that all the x:y SCN materials exhibit the presence of doping S in the structure of g-C3N4and higher capability in the photodegradation of Rhodamin B in aqueous solution under visible light condition than pure g-C3N4. Among the SCN samples, 75:25 SCN performed the highest photocatalytic activity, which is believed the presence of the largest amount of doping S in the matrix of g-C3N4, leading to reduction of their bandgap. The reduction of bandgap for S-doped g-C3N4materials compared to pure g-C3N4was proved by theoretical calculation.


2011 ◽  
Vol 71-78 ◽  
pp. 748-754 ◽  
Author(s):  
Yu Chao Tang ◽  
Xian Huai Huang ◽  
Chang Nian Wu ◽  
Li Hua Tang ◽  
Li Ping Xue ◽  
...  

Nitrogen doped TiO2 (N/TiO2) photocatalysts were prepared using a mechanochemica1 method with raw amorphous TiO2 as precursors and various nitrogenous compounds doses (NH4F, NH4HCO3, NH3·H2O, NH4COOCH3, and CH4N2O). The photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflection spectra (UV-Vis-DRS). Their photocatalytical activities were evaluated with the degradation of p-nitrophenol and methyl orange under UV or sunlight irradiation. The catalysts had a strong visible light absorption which corresponding to doped nitrogen and consequent oxygen deficient. Concentration of the nitrogen substances also affected the visible light adsorption of the TiO2. The XPS results indicated the doped nitrogen in the TiO2 may exist in the formation of O2Ti−N−H and/or O2Ti−N, nitrogen was in form of interstitial atom. The results of photocatalytic activity showed the visible light adsorption mechanisms, as the doped nitrogen species gave rise to a mid-gap level slightly above the top of the (O-2p) valence band, but not from the mixed band gap of the N-2p and O-2p electronic levels.


2011 ◽  
Vol 694 ◽  
pp. 85-90
Author(s):  
Dai Mei Chen ◽  
Hai Peng Ji ◽  
Jian Xin Wang ◽  
Jian Chen ◽  
Zheng Ming Wu ◽  
...  

To utilize visible light and separate of TiO2 nanoparticles more efficiently in photocatalytic reactions, nitrogen doped TiO2/sepiolite composites (N-TiO2/sep) with different nitrogen contents were prepared by a sol-gel method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. XRD showed that anatase-TiO2 nanoparticles were loaded on the surface of sepiolite. XPS revealed that N atoms could incorporate into the lattice of anatase TiO2 substituting the sites of oxygen atoms. UV-vis spectroscopy showed that the visible light absorption of N-TiO2/sep samples decreased with the increase of calciantion temperature and increased with the increase of N content. The photocatalytic activities of obtained N-TiO2/sep samples were evaluated by methylene blue degradation under visible light irradiation. It was found that the N-TiO2/sep samples had the higher photocatalytic activity than that of TiO2/sep.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jin-Hua Cai ◽  
Jin-Wang Huang ◽  
Han-Cheng Yu ◽  
Liang-Nian Ji

In order to utilize visible light more efficiently in the photocatalytic reaction, microspheres sensitized by 5-(4-allyloxy)phenyl-10,15,20-tri(4-methylphenyl)porphyrin (APTMPP) were prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen physisorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and UV-vis diffuse reflectance spectroscopy, and so forth, The characterization results indicated that APTMPP-MPS- was composed of the anatase crystal phase. The morphology of the composite materials was spheriform with size of 0.3–0.7 μm and the porphyrin was chemisorbed on the surface of through a Si–O–Ti bond. The photooxidation ofα-terpinene was employed as the model reaction to evaluate the photocatalytic activity of APTMPP-MPS- microspheres under visible light. The results indicated that the photodegradation ofα-terpinene was significantly enhanced in the presence of the APTMPP-MPS- compared with the nonmodified under visible light.


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