Synthesis of Er-doped Bi2WO6 and enhancement in photocatalytic activity induced by visible light

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94887-94894 ◽  
Author(s):  
Meng Wang ◽  
Ziyu Qiao ◽  
Minghao Fang ◽  
Zhaohui Huang ◽  
Yan'gai Liu ◽  
...  

1.5% Bi2WO6:Er3+ exhibited highest photocatalytic activity as the separation efficiency of the photogenerated electron–hole pairs is enhanced.

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050045
Author(s):  
Ning Liu ◽  
Huidong Xie ◽  
Jie Li ◽  
Yajuan Zhao ◽  
Na Wang

Brookite TiO2 was synthesized by a hydrothermal method, g-C3N4 was prepared by a pyrolytic method, brookite/g-C3N4 composites were prepared by a calcining method, and brookite/g-C3N4/BiOBr ternary composites were prepared by loading BiOBr on the surface of brookite/g-C3N4. XRD and XPS analysis of the composites confirmed the formation of brookite TiO2/g-C3N4/BiOBr. SEM and TEM results confirmed the as-prepared composites were nanosized. The optimum loading amount of BiOBr was 30%. The photocatalytic results showed that the brookite/g-C3N4/30%BiOBr composites degraded rhodamine B completely under visible light irradiation. The degradation ratio of brookite/g-C3N4/30%BiOBr toward rhodamine B was nearly 100% for 2[Formula: see text]h, which was much higher than that of brookite TiO2 and brookite/g-C3N4 catalysts. The reason for the improvement of photocatalytic activity might be because the composites promoted the formation of superoxide radicals and the separation efficiency of photogenerated electron-hole pairs. The photocurrent density of the brookite/g-C3N4/30%BiOBr was about 10 times higher than that of pure brookite. In addition, the brookite/g-C3N4/BiOBr showed a good repeatablity of photocatalysis.


2019 ◽  
Vol 48 (10) ◽  
pp. 3486-3495 ◽  
Author(s):  
Juying Lei ◽  
Bin Chen ◽  
Weijia Lv ◽  
Liang Zhou ◽  
Lingzhi Wang ◽  
...  

An inverse opal TiO2/g-C3N4 composite with excellent photogenerated electron–hole separation efficiency and enhanced visible light absorption efficiency was constructed.


2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.


RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27933-27939 ◽  
Author(s):  
Qingyan Nong ◽  
Min Cui ◽  
Hongjun Lin ◽  
Leihong Zhao ◽  
Yiming He

The coupling of FeVO4 nanorods with g-C3N4 promotes the separation efficiency of photogenerated electron–hole pairs, and subsequently enhances its photocatalytic activity in rhodamine photodegradation.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shuo Xu ◽  
Xiaoya Gao ◽  
Wenfeng Xu ◽  
Pengfei Jin ◽  
Yongmei Kuang

A series of ultrathin BiOCl 2D nanosheet photocatalysts were prepared by the TBAOH-assisted hydrolysis method in water. The effects of tetrabutylammonium hydroxide (TBAOH) dosages, chlorine source, preparation pH value, ultrasonic treatment, and magnetic stirring on the photocatalytic degradation dynamics of carbamazepine were examined under visible-light irradiation to optimize the preparation parameters. It was found that ultrathin BiOCl prepared with TBAOH dosages of 1 mmol and chlorine source of NaCl in the pH of 2 upon magnetic stirring of 6 h displayed the highest photocatalytic degradation rate constant (0.0038 min−1) of carbamazepine, which is 7.6 times higher than that with the ordinary BiOCl (without TBAOH). To clarify the mechanism on the outstanding photocatalytic activity of ultrathin BiOCl, the elemental composition/state, micromorphology, and separation efficiency of photogenerated electron-hole pairs were investigated by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and photoluminescence (PL). Results showed that the presence of oxygen vacancy, ultrathin nanosheet structure, and improved separation efficiency of photogenerated electron-hole pairs contributed to the excellent photocatalytic degradation activity of ultrathin BiOCl. The obtained result provides a novel method to fabricate ultrathin BiOCl with excellent photocatalytic degradation activity of carbamazepine under visible-light irradiation.


2020 ◽  
Vol 13 (03) ◽  
pp. 2050015 ◽  
Author(s):  
Lu Cheng ◽  
Nuo Yu ◽  
Yan Zhang ◽  
Zhun Shi ◽  
Haifeng Wang ◽  
...  

The development of photocatalysts with wide UV-Vis-near-infrared (NIR) photoabsorption has received tremendous interest for utilizing sunlight efficiently. In this work, Cu2(OH)PO4 superstructures are prepared by a simple hydrothermal route, and they have strong bandgap absorption in UV-Visible region and a distinctive plasmon resonance absorption in NIR region. Under the synergetic illumination of visible light and 980[Formula: see text]nm laser (3.0[Formula: see text]W[Formula: see text]cm[Formula: see text]), Cu2(OH)PO4 superstructures can degrade 89.2% MB with the elevated temperature ([Formula: see text]51∘C) of solution, which is higher than that from visible light group (50.0%), laser group (16.4%), and visible-light/exterior-heating group (62.5%, same temperature at [Formula: see text]51.0∘C). These facts reveal that Cu2(OH)PO4 superstructures exhibit NIR-laser enhanced photocatalytic activity, which not only comes from the photothermal effect-induced temperature elevation, but also mainly results from the increased production of photogenerated electron-hole pairs by NIR-laser. Therefore, Cu2(OH)PO4 superstructures can act as efficient photocatalyst with NIR-laser enhanced photocatalytic activity.


RSC Advances ◽  
2015 ◽  
Vol 5 (53) ◽  
pp. 42736-42743 ◽  
Author(s):  
Qian Zhang ◽  
Haoying Wang ◽  
Shaozheng Hu ◽  
Guang Lu ◽  
Jin Bai ◽  
...  

A g-C3N4/Bi2O2CO3 layered heterojunction nanocomposite exhibits more effective separation of photogenerated electron–hole pairs and a stable chemical structure, thus showing higher photocatalytic activity and stability.


2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue

Pure anatase TiO2 photocatalysts with different Ag contents were prepared via a simple sol-gel method. The as-prepared anatase Ag-doped TiO2 photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectra, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermal gravity and differential thermal analysis, scanning electron microscopy and N2 adsorption–desorption measurements (BET). Compared with pure TiO2, Ag-doped anatase TiO2 photocatalysts exhibited not only increases in light absorption in the visible region, the separation efficiency of electron–hole pairs and surface area, but also inhibition of the titania phase transition from anatase to rutile. Photoreduction results showed that Ag-doped anatase TiO2 photocatalysts have greatly improved photocatalytic activity, compared with pure TiO2, and the reduction of Cr(VI) under visible light irradiation was much higher than that of pure TiO2. The optimum Ag content was 1.0 mol%, which led to the complete reduction of Cr(VI) under visible light irradiation (λ > 420 nm) for 4 h. The enhanced photocatalytic activity was attributed to the synergic effect of the pure anatase structure, and the increased light absorption in the visible region, separation efficiency of electron–hole pairs and atomic ratio of Ag0:Ag2O.


RSC Advances ◽  
2016 ◽  
Vol 6 (59) ◽  
pp. 54060-54068 ◽  
Author(s):  
Saranyoo Chaiwichian ◽  
Khatcharin Wetchakun ◽  
Sukon Phanichphant ◽  
Wiyong Kangwansupamonkon ◽  
Natda Wetchakun

The formation of Fe-doped Bi2WO6–BiVO4composites could improve the separation efficiency of photogenerated electron–hole pairs, then increasing its photocatalytic activity.


2015 ◽  
Vol 3 (8) ◽  
pp. 4652-4658 ◽  
Author(s):  
Zhihong Chen ◽  
Fan Bing ◽  
Qiong Liu ◽  
Zhengguo Zhang ◽  
Xiaoming Fang

The excellent photocatalytic activity of Ag3PO4/Ag/SiC can be ascribed to the efficient separation of photogenerated electron–hole pairs through the Z-scheme.


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