scholarly journals Enhanced Photocatalytic Activity of Electrospun β-Ga2O3 Nanofibers via In-Situ Si Doping Using Tetraethyl Orthosilicate

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1005 ◽  
Author(s):  
Tae Hee Yoo ◽  
Heejoong Ryou ◽  
In Gyu Lee ◽  
Byung Jin Cho ◽  
Wan Sik Hwang

β-Ga2O3 has attracted considerable attention as an alternative photocatalyst to replace conventional TiO2 under ultraviolet-C irradiation due to its high reduction and oxidation potential. In this study, to enhance the photocatalytic activity of β-Ga2O3, nanofibers are formed via the electrospinning method, and Si atoms are subsequently doped. As the Si concentration in the β-Ga2O3 nanofiber increases, the optical bandgap of the β-Ga2O3 nanofibers continuously decreases from 4.5 eV (intrinsic) to 4.0 eV for the Si-doped (2.4 at. %) β-Ga2O3 nanofibers, and accordingly, the photocatalytic activity of the β-Ga2O3 nanofibers is enhanced. This higher photocatalytic performance with Si doping is attributed to the increased doping-induced carriers in the conduction band edges. This differs from the traditional mechanism in which the doping-induced defect sites in the bandgap enhance separation and inhibit the recombination of photon-generated carriers.

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 53 ◽  
Author(s):  
Yuanyuan Li ◽  
Xiaofang Tian ◽  
Yaoqiong Wang ◽  
Qimei Yang ◽  
Yue Diao ◽  
...  

Using solar energy to remove antibiotics from aqueous environments via photocatalysis is highly desirable. In this work, a novel type-II heterojunction photocatalyst, MgSn(OH)6/SnO2, was successfully prepared via a facile one-pot in situ hydrothermal method at 220 °C for 24 h. The obtained heterojunctions were characterized via powder X-ray diffraction, Fourier-transform infrared spectroscopy, transmission electron microscopy, and ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic performance was evaluated for photodegradation of tetracycline solution under ultraviolet irradiation. The initial concentration of tetracycline solution was set to be 20 mg/L. The prepared heterojunctions exhibited superior photocatalytic activity compared with the parent MgSn(OH)6 and SnO2 compounds. Among them, the obtained MgSn(OH)6/SnO2 heterojunction with MgCl2·6H2O:SnCl4·5H2O = 4:5.2 (mmol) displayed the highest photocatalytic performance and the photodegradation efficiency conversion of 91% could be reached after 60 min under ultraviolet irradiation. The prepared heterojunction maintained its performance after four successive cycles of use. Active species trapping experiments demonstrated that holes were the dominant active species. Hydroxyl radicals and superoxide ions had minor effects on the photocatalytic oxidation of tetracycline. Photoelectrochemical measurements were used to investigate the photocatalytic mechanism. The enhancement of photocatalytic activity could be assigned to the formation of a type-II junction photocatalytic system, which was beneficial for efficient transfer and separation of photogenerated electrons and holes. This research provides an in situ growth strategy for the design of highly efficient photocatalysts for environmental restoration.


RSC Advances ◽  
2017 ◽  
Vol 7 (52) ◽  
pp. 32592-32600 ◽  
Author(s):  
Yan Xu ◽  
Yinyan Gong ◽  
Hui Ren ◽  
Wenbo Liu ◽  
Lengyuan Niu ◽  
...  

Introducing alkali halides during thermal condensation of melamine disturbs periodic ordering in the basal plane, reduces the band gap, and facilitates charge carrier transfer and separation, and thus enhances the photocatalytic performance of g-C3N4.


2015 ◽  
Vol 40 (39) ◽  
pp. 13431-13442 ◽  
Author(s):  
Sanjay B. Kokane ◽  
S.D. Sartale ◽  
K.G. Girija ◽  
Jagannath ◽  
R. Sasikala

2019 ◽  
Vol 7 (39) ◽  
pp. 22385-22397 ◽  
Author(s):  
Peiqin Deng ◽  
Jinsong Xiong ◽  
Shuijin Lei ◽  
Wei Wang ◽  
Xiuling Ou ◽  
...  

Nickel formate is used for the first time for high-level in situ Ni-doping of g-C3N4 for enhanced photocatalytic activity in both dye-degradation and H2-evolution.


RSC Advances ◽  
2015 ◽  
Vol 5 (78) ◽  
pp. 63264-63270 ◽  
Author(s):  
Lei Shi ◽  
Lin Liang ◽  
Fangxiao Wang ◽  
Mengshuai Liu ◽  
Tao Liang ◽  
...  

pg-C3N4 prepared through in situ bubble template showed large surface area and low recombination rate of photoinduced electron–hole pairs, leading to enhanced visible-light photocatalytic activity for degrading pollutants and splitting water to H2.


RSC Advances ◽  
2014 ◽  
Vol 4 (23) ◽  
pp. 11750-11757 ◽  
Author(s):  
Junghyun Choi ◽  
P. Sudhagar ◽  
P. Lakshmipathiraj ◽  
Jung Woo Lee ◽  
Anitha Devadoss ◽  
...  

Demonstration of the role of electrode geometry on in situ Gd-doping and their effects in the photocatalytic activity.


POSITRON ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Lia Destiarti ◽  
Oktaviardi Bityasmawan Abdillah ◽  
Retno Maharsi ◽  
Octia Floweri ◽  
Ferry Iskandar

In this work, the photocatalytic performance of electrochemically exfoliated graphite (EG) with low copper addition (≤ 5 wt.%) was studied. Composites of EG/Cu/Cu2O were successfully prepared by microwave-assisted in situ reduction method. FTIR spectra of the samples showed that the main functional groups of graphite were detected in the samples. XRD characterization further proved the presence of EG, Cu, and Cu2O in the samples. The higher proportion of Cu2O presented in the samples prepared with a higher amount of Cu2+. SEM analysis showed that Cu2O/Cu particles were homogeneously deposited on the surface of EG. The composites of EG, Cu, and Cu2O with a varied amount of Cu (1 and 5 wt. %) in EG / Cu2+ mixture were examined as photocatalyst in the degradation process of Rhodamine B (RhB). The photocatalytic degradation of RhB was analysed by observing its decolorization within a set time of irradiation. UV-Vis analysis revealed that the degradation of RhB in EG/Cu/Cu2O A and B for 105 minutes was 26 and 35 %, respectively. The result demonstrates that the sample with a larger amount of Cu2O (sample B, Cu 5 wt.%) shows higher photocatalytic activity in the degradation of RhB.


2019 ◽  
Vol 7 (18) ◽  
pp. 5451-5460 ◽  
Author(s):  
Wubin Wu ◽  
Jingchao Wang ◽  
Tianyong Zhang ◽  
Shuang Jiang ◽  
Xiaoyuan Ma ◽  
...  

Several different fusiform-shaped Ag/AgCl@MIL-88A (ACML) materials with good photocatalytic activity were prepared successfully by using the in situ growth method.


RSC Advances ◽  
2018 ◽  
Vol 8 (73) ◽  
pp. 42233-42245 ◽  
Author(s):  
Ningmei Tang ◽  
Youji Li ◽  
Feitai Chen ◽  
Zhenying Han

CdS@GMT/GR exhibits high photocatalytic activity due to its direct Z-scheme structure obtained by immobilizing CdS quantum dots in the channels of GMT nanocrystals.


NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950096 ◽  
Author(s):  
Wen Gao ◽  
Chengjia Zhang ◽  
Sainan Cui ◽  
Qian Liang ◽  
Song Xu ◽  
...  

In this study, LaFeO3/ZnIn2S4 composites were synthesized via in situ synthesis. The composition, structure and optical absorption properties of LaFeO3/ZnIn2S4 were characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy, fluorescence spectroscopy (PL), Fourier Transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The photocatalytic activity of the LaFeO3/ZnIn2S4 photocatalyst was determined based on the degradation of methyl orange (MO). LaFeO3/ZnIn2S4 composites showed much better photocatalytic performance compared with pure LaFeO3 and ZnIn2S4. The enhanced photocatalytic performance was attributed to intimately contacted interfaces and charge transfer channels which can effectively transfer and separate the photogenerated charge carriers.


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