Sulfur-Doped g-C3N4 with Enhanced Visible-Light Photocatalytic Activity

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.

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.


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.


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.


2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.


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.


2012 ◽  
Vol 621 ◽  
pp. 172-177 ◽  
Author(s):  
Su Hua Chen ◽  
Bi Xuan Wang ◽  
Xian Hua Qiu ◽  
Zhen Sheng Xiong

In order to improve ZnWO4 photocatalytic activity under visible light, the C, N-codoped ZnWO4 nanoparticles have been successfully synthesized by choosing C3N4 generated from tripolycyanamide pyrolysis as the source of Carbon and Nitrogen and the influence of C3N4 concentration on structural, optical and morphological properties of C, N-codoped ZnWO4 using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM) and photocatalytic decoloration of rhodamine B (RhB) aqueous solution under visible light. It was found that the presence of carbon and nitrogen could not improve the crystallization of ZnWO4 species but could enhance their photoabsorption property in the visible region. The results also showed that the photocatalytic activity of the as-prepared ZnWO4 is higher than that of pure ZnWO4 with the optimum effect occurring at RC3N4 = 9 % (the weight ratio of tripolycyanamide to ZnWO4)


2016 ◽  
Vol 09 (02) ◽  
pp. 1650026 ◽  
Author(s):  
Fengjun Zhang ◽  
Zhi Wang ◽  
Tianye Wang ◽  
Liwei Jia ◽  
Chao Wang ◽  
...  

In this study, Bi2WO6/Bi2O3-loaded polyurethane sponge composite photocatalyst was successfully synthesized via a facile two-step approach. The composite was characterized by X-ray diffraction, ultraviolet-visible diffuse reflectance, and scanning electron microscopy. The Bi2WO6/Bi2O3 photocatalyst was successfully loaded on polyurethane sponge and the composite displayed enhanced absorption in the ultraviolet-to-visible light region. Furthermore, the composite exhibited enhanced photocatalytic activity and reusability towards the degradation of rhodamine B (RhB) under visible light. This work demonstrates a facile method for synthesizing Bi2WO6/Bi2O3-loaded polyurethane sponge with enhanced photocatalytic activity and easy immobilization of the photocatalyst for application in environmental purification.


2014 ◽  
Vol 898 ◽  
pp. 23-26
Author(s):  
Jing Li ◽  
Wei Sun ◽  
Wei Min Dai ◽  
Yong Cai Zhang

TiO2/SnS2 nanocomposite was synthesized via hydrothermal treatment of tin (IV) chloride pentahydrate, thioacetamide and TiO2 nanotubes in deionized water at 150 °C for 3 h. The structure, composition and optical property of the as-synthesized nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic property was tested in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation. It was observed that TiO2 nanotubes exhibited no photocatalytic activity, whereas TiO2/SnS2 nanocomposite exhibited photocatalytic activity in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation.


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.


2013 ◽  
Vol 68 (10) ◽  
pp. 2178-2185 ◽  
Author(s):  
Zhihui Xu ◽  
Ming Zhang ◽  
Jingyu Wu ◽  
Jianru Liang ◽  
Lixiang Zhou ◽  
...  

In this study, a novel TiO2/β-FeOOH composite photocatalyst was synthesized by a hydrothermal method. X-ray diffraction, Fourier transform infrared spectrum, UV-vis diffuse reflectance spectra and scanning electron microscopy (SEM) were used to characterize the composite photocatalyst. The photocatalytic activity of the prepared composite photocatalyst was evaluated in a heterogeneous photo-Fenton-like process using methyl orange (MO) as target pollutant. The TiO2/β-FeOOH composites exhibited higher photocatalytic activity than pure β-FeOOH and TiO2 under visible-light irradiation. The enhanced photocatalytic activity can be ascribed to the formation of TiO2/β-FeOOH heterostructure, which plays an important role in expanding the photoactivity to the visible light region and in effectively prolonging the lifetime of photoinduced electrons and holes. Further investigation revealed that the 25TiO2/β-FeOOH composite synthesized with the TiO2/Fe3+ in a mole ratio of 25:75 showed the highest catalytic activity.


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