Synthesis of Direct Z-Scheme MnWO4/g-C3N4 Photocatalyst with Enhanced Visible Light Photocatalytic Activity

NANO ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. 1750129 ◽  
Author(s):  
Kuili Liu ◽  
Jinlin Li ◽  
Xu Yan ◽  
Weidong Shi

In this study, direct Z-scheme MnWO4/g-C3N4 photocatalyst was fabricated via facile hydrothermal method. Compared with pristine graphitic carbon nitride (g-C3N4) and manganous tungstate (MnWO4), the prepared MnWO4/g-C3N4 photocatalyst showed obviously enhanced photocatalytic activity for Rhodamine B (RhB) degradation under visible light irradiation. The MnWO4/g-C3N4 photocatalyst prepared with 10% MnWO4 (MC10%) showed the highest photocatalytic activity among all samples, which is about 2.3 and 12.7 times than that of pristine g-C3N4 and MnWO4, respectively. This enhancement is due to the strong light absorption and efficient electron–hole separation of direct Z-scheme MnWO4/g-C3N4 photocatalyst. Electron spin resonance (ESR) experiments and active species trapping experiments revealed that [Formula: see text]OH and [Formula: see text] are the main active species in the photocatalytic process. This work may be beneficial for designing MnWO4-based Z-scheme photocatalyst for application in environmental remediation.

RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 40028-40033 ◽  
Author(s):  
Hao Xu ◽  
Zhixing Gan ◽  
Weiping Zhou ◽  
Zuoming Ding ◽  
Xiaowei Zhang

Insufficient visible light absorption and fast recombination of the photogenerated electron–hole pairs have seriously hampered the photocatalytic performance of graphitic carbon nitride (g-C3N4) up to now.


2019 ◽  
Vol 54 (3) ◽  
pp. 257-264
Author(s):  
Jin Xu ◽  
Dasheng Gao ◽  
Shuang Cui ◽  
Xiaohua Wang ◽  
Ningning Liu

Abstract Through a simple grinding method, AgI/TiO2 composites were successfully synthesized. The as-prepared AgI/TiO2 composites were used as photocatalysts for Rhodamine B (RhB) degradation under visible light irradiation and exhibited excellent photocatalytic performance. In the presence of composites, almost 100% RhB was decomposed after 60 min. The photocatalytic activity of AgI/TiO2-0.5 composite was optimal, which was 9.5 times higher than that of pristine TiO2, and 15.6 times higher than that of AgI. Moreover, experimental results revealed that the improved photocatalytic activity was not only ascribed to the loading AgI but also resulted from the method that enabled the exposure of more active sites in the composites. In addition, the intimate interfacial contact obtained by this method could also promote the efficient separation of photogenerated electron-hole pairs. Moreover, the possible photocatalytic active species and the stability of the photocatalyst were investigated in detail.


2021 ◽  
Author(s):  
yin zhao ◽  
hong qin ◽  
Qianlan luo ◽  
ziwei wang ◽  
han wang ◽  
...  

Abstract Using semiconductor photocatalysts for antibiotic contaminants degradation under visible light has become a hot topic in recent years. Herein, a novel cadmium doped graphite phase carbon nitride (Cd/g-C3N4) photocatalyst was successfully constructed via 60 °C oil bath method to degrade tetracycline. Experimental and characterization results revealed that cadmium was well doped at g-C3N4 surface and exhibited high intercontact with g-C3N4. Meanwhile, Cd/g-C3N4 presented excellent electrical conductivity and inhibited the recombination of electron-hole pairs. The introduction of cadmium significantly improved the photocatalytic activity and the degradation efficiency of 10 Cd/g-C3N4 reached to 89.09%, which was exceeded 2.0 times than pure g-C3N4 (43.99%). Additionally, the quenching experiments and electron spin-resonance tests exhibited holes (h+), hydroxyl radicals (•OH) and superoxide radicals (•O2−) were dominated active species in TC degradation. Furthermore, the effects of various conditions on the reaction process, such as different pH, initial TC concentrations and catalyst dosage, were also researched. This work gives a reasonable point to synthesize high-efficiency and economic photocatalysts.


2021 ◽  
Vol 898 (1) ◽  
pp. 012025
Author(s):  
Wei’e Wang ◽  
Bohong Wu ◽  
Zhiyang Gao ◽  
Yuguang Lv

Abstract Photocatalysts are mainly divided into two categories: one is that they have good response to sunlight and visible light, such as BiVO4 and Fe2O3; One is that it has its own defects and can not make full use of the energy converted by visible light. In recent years, a class of oxides have attracted much attention because of their good performance of visible light photocatalytic degradation of pollutants. People also have a strong interest in the research of compound oxides in pollutant degradation. In order to further clarify the photocatalytic mechanism of GCB composite samples, different capture agents were added to determine the main active species in the photocatalytic process. Only through the method of modification, the synergistic effect can enhance its photocatalytic activity. 1% g-C3N4/BiVO4(GCB) sample, drhb = 90.4%, the photocatalytic activity did not change significantly after adding IPA. After adding EDTA and VC, the photocatalytic activity decreased, drhb = 32.6% and drhb = 51%. Therefore, the experiments show that h+ and ·O2- are active species of GCB catalytic system, O2 is more important for RHB degradation.


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.


2016 ◽  
Vol 45 (41) ◽  
pp. 16519-16525 ◽  
Author(s):  
Jiao Xue ◽  
Runwei Wang ◽  
Zongtao Zhang ◽  
Shilun Qiu

C, N co-modified niobium pentoxide (Nb2O5) nanoneedles have been successfully synthesized via a facile hydrothermal method with Niobium Chloride (NbCl5) as a precursor and triethylamine as both the carbon and nitrogen source.


2014 ◽  
Vol 5 ◽  
pp. 658-666 ◽  
Author(s):  
Difa Xu ◽  
Shaowen Cao ◽  
Jinfeng Zhang ◽  
Bei Cheng ◽  
Jiaguo Yu

Silver chromate (Ag2CrO4) photocatalysts are prepared by microemulsion, precipitation, and hydrothermal methods, in order to investigate the effect of preparation methods on the structure and the visible-light photocatalytic activity. It is found that the photocatalytic activity of the prepared Ag2CrO4was highly dependent on the preparation methods. The sample prepared by microemulsion method exhibits the highest photocatalytic efficiency on the degradation of methylene blue (MB) under visible-light irradiation. The enhanced photocatalytic activity could be ascribed to the smaller particle size, higher surface area, relatively stronger light absorption, and blue-shift absorption edge, which result in the adsorption of more MB molecules, a shorter diffusion process of more photogenerated excitons, and a stronger oxidation ability of the photogenerated holes. Considering the universalities of microemulsion, precipitation, and hydrothermal methods, this work may also provide a prototype for the comparative study of semiconductor based photocatalysis for water purification and environmental remediation.


2019 ◽  
Vol 43 (1) ◽  
pp. 162-167 ◽  
Author(s):  
Da Xu ◽  
Chang Liu ◽  
Hairui Wang ◽  
Limin Chang ◽  
Xue Lin

Here, g-C3N4 quantum dot (CNQDs)/Bi2MoO6 nanoheterostructures were successfully synthesized. The CNQDs/Bi2MoO6 nanocomposite exhibited enhanced photocatalytic activity.


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