scholarly journals Phthalocyanine-sensitized hollow ZnO spheres as an efficient visiblie-light photocatalyst for water treatment

2020 ◽  
Vol 194 ◽  
pp. 04057
Author(s):  
Cong Liu ◽  
Qian Duan

A novel phthalocyanine-sensitized hollow ZnO spheres as an efficient visiblie-light photocatalyst had been prepared successfully. Firstly, a unique hollow ZnO microsphere had been prepared by a facile solvothermal method followed by calcination. Secondly, zinc-tetracarboxyl-phthalocyanine (Pc) impregnated onto the surface of hollow ZnO microsphere. The obtained photocatalyst Pc/ZnO was characterized by XRD, SEM and EDS. The hollow Pc/ZnO hierarchical nanostructure improved the electron-hole separation more effectively and Pc loaded on the surface of ZnO microsphere to enhance photocatalytic activity under visible light. In our photocatalytic experiments, the hollow Pc/ZnO microsphere showed excellent photocatalytic performance under visible light for the removal of Rhodamine B (RhB). As a result, our work provided an effective and green photocatalyst for water treatment.

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2206
Author(s):  
Gaoqian Yuan ◽  
Gen Zhang ◽  
Kezhuo Li ◽  
Faliang Li ◽  
Yunbo Cao ◽  
...  

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min−1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.


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.


RSC Advances ◽  
2019 ◽  
Vol 9 (41) ◽  
pp. 23545-23553 ◽  
Author(s):  
Jianhui Li ◽  
Fan Yang ◽  
Quan Zhou ◽  
Lijie Wu ◽  
Wenying Li ◽  
...  

The ternary magnetic Fe3O4/BiOBr/BiOI (x : 3 : 1) photocatalysts were successfully synthesized by a facile solvothermal method.


2018 ◽  
Vol 238 ◽  
pp. 03007
Author(s):  
Xiquan Wang ◽  
Nan Zhang ◽  
Gao Wang

Bi2S3-sensitized BiFO3 (BFO) photocatalyst (Bi2S3/BFO) was successfully synthesized through a facile and environmental ion exchange method between BFO and Thiosurea (H2NCSNH2, TU). The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and UV-vis diffuse reflection spectroscopy (DRS). The obtained Bi2S3/BFO composites showed excellent photocatalytic performance for decomposing Rhodamine B (RhB) compared with pure BFO under visible light irradiation (λ>400nm). 5% Bi2S3/BFO exhibited the highest photocatalytic activity and excessive amount of Bi2S3 would result in the decrease of photocatalytic activity of BFO. The mechanism of enhanced photocatalytic activity was proposed on the basis of the calculated energy band positions.


2013 ◽  
Vol 423-426 ◽  
pp. 163-166 ◽  
Author(s):  
Bao Wei Cao ◽  
Yun Hua Xu

Bi2WO6 doped with iodine ions were synthesized using hydrothermal method and their photocatalytic activities to degrade Rhodamine B (RhB) under visible-light was investigated. The successful incorporation of I ions in Bi2WO6 was proved by XRD and XPS. UV-vis absorption spectra results show that I ion was successfully doped into Bi2WO6 and a red shift for I-doped Bi2WO6 appeared when compared to pure Bi2WO6. The photocatalytic activities of the photocatalysts were evaluated by the decolorization of RhB under visible-light irradiation. The results showed that the photocatalytic activity of I-doped Bi2WO6 was much higher than the undoped Bi2WO6.


2021 ◽  
Author(s):  
Rui Zhang ◽  
ziyin chen ◽  
Chen Zhao ◽  
Kunlin Zeng ◽  
Lu Cai ◽  
...  

Abstract A novel binary BiSI/Ag2CO3 photocatalyst with excellent visible light-driven photocatalytic performance was prepared. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and electrochemical impedance spectroscopy (EIS). The photocatalytic activity of the samples were evaluated by photocatalytic degradation of rhodamine B(RhB) under the irradiation of visible light. The results showed that the BiSI improves the photocatalytic activity of BiSI/Ag2CO3. Moreover, when the mass ratio of BiSI in BiSI/Ag2CO3 composites was 40%, the as-prepared BiSI/Ag2CO3 composite exhibited the best photocatalytic activity for degrading RhB. Finally, the possible mechanism for photodegradation over the BiSI/Ag2CO3 composites is also proposed.


Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 66 ◽  
Author(s):  
Xinxin Zhao ◽  
Hua Yang ◽  
Ziming Cui ◽  
Xiangxian Wang ◽  
Zao Yi

Bi4Ti3O12 square plates were synthesized via a hydrothermal route, and their growth process was systematically investigated. Carbon quantum dots (CQDs) were prepared using glucose as the carbon source, which were then assembled on the surface of Bi4Ti3O12 square plates via a hydrothermal route with the aim of enhancing the photocatalytic performance. XRD (X-ray powder diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), UV-vis DRS (diffuse reflectance spectroscopy), XPS (X-ray photoelectron spectroscopy), FTIR (Fourier transform infrared spectroscopy), PL (photoluminescence) spectroscopy, EIS (electrochemical impedance spectroscopy) and photocurrent spectroscopy were used to systematically characterize the as-prepared samples. It is demonstrated that the decoration of CQDs on Bi4Ti3O12 plates leads to an increased visible light absorption, slightly increased bandgap, increased photocurrent density, decreased charge-transfer resistance, and decreased PL intensity. Simulated sunlight and visible light were separately used as a light source to evaluate the photocatalytic activity of the samples toward the degradation of RhB in aqueous solution. Under both simulated sunlight and visible light irradiation, CQDs@Bi4Ti3O12 composites with an appropriate amount of CQDs exhibit obviously enhanced photocatalytic performance. However, the decoration of excessive CQDs gives rise to a decrease in the photocatalytic activity. The enhanced photocatalytic activity of CQDs-modified Bi4Ti3O12 can be attributed to the following reasons: (1) The electron transfer between Bi4Ti3O12 and CQDs promotes an efficient separation of photogenerated electron/hole pairs in Bi4Ti3O12; (2) the up-conversion photoluminescence emitted from CQDs could induce the generation of additional electron/hole pairs in Bi4Ti3O12; and (3) the photoexcited electrons in CQDs could participate in the photocatalytic reactions.


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.


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.


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