scholarly journals Synthesis of Ag and AgCl co-doped ZIF-8 hybrid photocatalysts with enhanced photocatalytic activity through a synergistic effect

RSC Advances ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 698-704 ◽  
Author(s):  
Yanqiu Jing ◽  
Qiang Lei ◽  
Chun Xia ◽  
Yu Guan ◽  
Yide Yang ◽  
...  

Recently, Ag/AgCl composites with different structures have been widely studied and used as photocatalysts to degrade dye pollutants, due to their high separation efficiency of electron–hole pairs under visible light irradiation.

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.


2020 ◽  
Vol 35 (3) ◽  
pp. 312-320
Author(s):  
Zuowei Zhang ◽  
Hongshun Hao ◽  
Shanshan Jin ◽  
Yunxia Hou ◽  
Hongman Hou ◽  
...  

Abstract


2020 ◽  
Vol 46 (15) ◽  
pp. 24744-24752 ◽  
Author(s):  
Weichao Li ◽  
Linkun Xie ◽  
Liexing Zhou ◽  
Josias Ochoa-Lozano ◽  
Chen Li ◽  
...  

2019 ◽  
Vol 9 (5) ◽  
pp. 1178-1188 ◽  
Author(s):  
Taiping Xie ◽  
Yaoyu Zhang ◽  
Weiyuan Yao ◽  
Yue Liu ◽  
Haiqiang Wang ◽  
...  

The strong protonated hydroxyl groups around Bi vacancies could efficiently promote the separation of photoexcited electron–hole pairs.


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.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1332
Author(s):  
Duc Quang Dao ◽  
Thi Kim Anh Nguyen ◽  
Thanh-Truc Pham ◽  
Eun Woo Shin

Co-doped NiTiO3/g-C3N4 composite photocatalysts were prepared by a modified Pechini method to improve their photocatalytic activity toward methylene blue photodegradation under visible light irradiation. The combination of Co-doped NiTiO3 and g-C3N4 and Co-doping into the NiTiO3 lattice synergistically enhanced the photocatalytic performance of the composite photocatalysts. X-ray photoelectron spectroscopy results for the Co-doped NiTiO3/g-C3N4 composite photocatalysts confirmed Ti-N linkages between the Co-doped NiTiO3 and g-C3N4. In addition, characteristic X-ray diffraction peaks for the NiTiO3 lattice structure clearly indicated substitution of Co into the NiTiO3 lattice structure. The composite structure and Co-doping of the C-x composite photocatalysts (x wt % Co-doped NiTiO3/g-C3N4) not only decreased the emission intensity of the photoluminescence spectra but also the semicircle radius of the Nyquist plot in electrochemical impedance spectroscopy, giving the highest kapp value (7.15 × 10−3 min−1) for the C-1 composite photocatalyst.


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