A facile wet chemical route to prepare ZnO/TiO2 nanotube composites and their photocatalytic activities

2010 ◽  
Vol 25 (7) ◽  
pp. 1278-1287 ◽  
Author(s):  
Lei Zhu ◽  
Guocong Liu ◽  
Xuechen Duan ◽  
Zhi Jian Zhang

Highly dispersed ZnO/TiO2 nanotube composites (NTCs) were successfully synthesized by a facile ethylenediamine-assisted deposition-precipitation route. The characterizations from x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller, Fourier transform infrared, and ultraviolet-visible spectra revealed that hexagonal wurtzite phase ZnO NPs with an average size of about 2 nm were homogeneously dispersed and anchored on the surface of TiO2 nanotubes (NTs) to form ZnO/TiO2 NTCs. The as-prepared ZnO/TiO2 NTCs with the atom ratio Zn/Ti of 1:4 exhibited excellent photocatalytic activity for photodegradation of methyl orange compared with P25 and pure TiO2 NTs, which were mainly caused by an increase of interfacial charge transfer reactions and a decrease of electron-hole pair recombination on ZnO-TNTs heterojunction. Furthermore, ZnO/TiO2 NTCs possessed favorable recycle efficiency due to their relatively high sedimentation rate and only a slight decrease of photocatalytic activity after a six time recycle.

2011 ◽  
Vol 399-401 ◽  
pp. 1139-1142
Author(s):  
Jia Gui Li ◽  
Guo Cong Liu ◽  
Hui Dong

Highly dispersed ZnO/TiO2nanotube composites (NTCs) were successfully synthesized via a facile ethylenediamine-assisted deposition-precipitation route. This NTCs were characterized by XRD, TEM, and photcatalytic testing.The results revealed that hexagonal wurtzite phase ZnO NPs with an average size of about 2 nm were homogeneously dispersed and anchored on the surface of TiO2nanotubes (NTs) to form ZnO/TiO2NTCs, which exhibited excellent photocatalytic activity for photodegradation of methyl orange (MO) compared with P25 and Pure TiO2NTs. Furthermore, ZnO/TiO2NTCs possessed very favorable recycle efficiency due to their relatively high sedimentation rate and only slightly decrease of photocatalytic activity after a six- time recycle.


NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jiang Zhang ◽  
Zheng-Hong Huang ◽  
Yong Xu ◽  
Feiyu Kang

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.


Author(s):  
Irwing M. Ramírez-Sánchez ◽  
Erick R. Bandala

Iron Doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe3+) was in the lattice of TiO2 and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radical (&bull;OH) and estriol (E3) degradation. Fe-TiO2 materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO2 (zero-iron TiO2) and Aeroxide&reg; TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Yinzhen Wang ◽  
Ning Li ◽  
Pingping Duan ◽  
Xuwei Sun ◽  
Benli Chu ◽  
...  

β-Ga2O3nanorods are prepared by hydrothermal method and characterized by X-ray diffraction, high-resolution transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectra. The results reveal that high crystallinity, monoclinic phase ofβ-Ga2O3nanorods were prepared with a diameter of about 60 nm and length of 500 nm. Photoluminescence study indicates that theβ-Ga2O3nanorods exhibit a broad blue light emission at room temperature. Theβ-Ga2O3nanorods displayed high photocatalytic activity under simulated solar irradiation; after 2 h irradiation, over 95% of methylene blue solution and over 90% of methyl orange solution were decolorized. Since this process does not require additional hydrogen peroxide and uses solar light, it can be developed as an economically feasible and environmentally friendly method to treat dye effluent.


Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 672 ◽  
Author(s):  
Zuzanna Bielan ◽  
Agnieszka Sulowska ◽  
Szymon Dudziak ◽  
Katarzyna Siuzdak ◽  
Jacek Ryl ◽  
...  

In the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation and reuse of the nanometer-sized photocatalyst from the suspension after the treatment process. The obtained Fe3O4@SiO2/d-TiO2-Pt/Cu photocatalysts were characterized by X-ray diffractometry (XRD) and specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Further, the mechanism of phenol degradation and the role of four oxidative species (h+, e−, •OH, and •O2−) in the studied photocatalytic process were investigated.


2007 ◽  
Vol 124-126 ◽  
pp. 1229-1232 ◽  
Author(s):  
Myoung Seok Sung ◽  
Yoon Bok Lee ◽  
Yong Jin Kim ◽  
Yang Do Kim

Cadmium selenide(CdSe) nanoparticles were prepared in the aqueous solution containing isopropyl alcohol by the ultrasonic irradiation at room temperature. The cadmium chloride (CdCl2) and sodium selenosulfate (Na2SeSO3) were used as the cadmium and selenium source, respectively. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-Vis absorption spectra and PL spectra were used to characterize the CdSe nanoparticles. XRD analysis revealed the formation of cubic structure CdSe. TEM images showed aggregated CdSe nanoparticles with the size of nanometer scale. Average size of CdSe nanoparticles were about 3.9, 5.0 and 5.1nm with sonication time of 6, 30 and 40 minutes, respectively. The surface emission became less intensive and shifted to red with increasing irradiation time. This paper presents the effects of ultrasonic on the formation of CdSe nanoparticles and its characteristics.


NANO ◽  
2014 ◽  
Vol 09 (06) ◽  
pp. 1450063
Author(s):  
JIAHUI ZHANG ◽  
LILI ZHANG ◽  
JIN HUANG ◽  
SHOUYONG ZHOU ◽  
HAIQUN CHEN ◽  
...  

Palygorskite (denoted as Pal) was used as an economical carrier of hybrid photocatalyst TiO 2– Fe x O yvia an in situ depositing technique (marked as Pal– TiO 2– Fe x O y). The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), brunner-emmet-teller (BET) measurements, X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectra measurements. Results showed that TiO 2– Fe x O y composite particles with average size of about 10 nm were loaded onto the Pal fibers' surface. Fe x O y acted not only as magnetic source but also took part in the formation of TiO 2– Fe x O y heterojunction structure, which resulted in the obvious absorption in visible light region for the obtained Pal– TiO 2– Fe x O y composite photocatalyst. The obtained Pal– TiO 2– Fe x O y shows excellent photocatalytic activity toward photodegradation of Methyl orange (MO) under visible light irradiation and the degradation ratio reached 94% within 180 min. Moreover, Pal– TiO 2– Fe x O y could be readily recovered from the reaction solution by the magnet. Possible mechanism for the enhancement was also proposed.


2011 ◽  
Vol 335-336 ◽  
pp. 460-463 ◽  
Author(s):  
Hong Mei Wang ◽  
Da Peng Zhou ◽  
Yuan Lian ◽  
Ming Pang ◽  
Dan Liu

Hexagonal flower-like CdS nanostructures were successfully synthesized through a facile hydrothermal method with thiourea as sulfur source. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the structural and morphological characterizations of the products were performed. The photocatalytic activity of CdS nanostructures had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial CdS powders, which indicated that the as-syntherized CdS nanostructures exhibited enhanced photocatalytic activity for degradation of RB. The possible growth mechanism of CdS nanostructures was proposed in the end.


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.


Sign in / Sign up

Export Citation Format

Share Document