Synthesis of g-C3N4/CuS Heterojunction with Enhanced Photocatalytic Activity Under Visible-Light

2020 ◽  
Vol 20 (9) ◽  
pp. 5896-5905
Author(s):  
Fan Wang ◽  
Qingru Zeng ◽  
Jinping Tang ◽  
Liang Peng ◽  
Jihai Shao ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Separation Efficiency ◽  
Photocatalytic Property ◽  
Photogenerated Electron ◽  
Light Irradiation ◽  
Electron Hole ◽  
Photocatalytic System ◽  
Composite Photocatalysts ◽  
The Stability

Novel g-C3N4/CuS hybrid photocatalysts were synthesized successfully via a facile hydrothermal method. Characterization results of the photocatalysts showed that especial heterostructure had formed between g-C3N4 and CuS, and possess suitable matched band potential. The composite photocatalysts displayed strong UV-visible light absorption ability in the range from 200 to 800 nm. Photocatalytic performance of the photocatalysts were evaluated via photooxidation of methyl orange (MO) under visible-light irradiation. Hybrid photocatalysts showed better photocatalytic properties than that of pure g-C3N4 or CuS. The 60% g-C3N4/CuS sample proved the supreme photocatalytic property. The integrated g-C3N4 and CuS heterojunction elevated the separation efficiency of photogenerated electron–hole pairs, and increased the photo-decoloration efficiency of MO under visible-light irradiation. A four-cycle repeatability experiment was carried out to investigate the stability of hybrid photocatalysts in the photocatalyst reaction. Radical capture experiments proved that photogenerated e−, h+ and .OH were responsible for MO photo-decoloration. In addition, the potential mechanism of the photocatalytic system g-C3N4/CuS+H2O2+vis are presented.

scholarly journals Tunable Synthesis of Ultrathin BiOCl 2D Nanosheets for Efficient Photocatalytic Degradation of Carbamazepine upon Visible-Light Irradiation

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shuo Xu ◽  
Xiaoya Gao ◽  
Wenfeng Xu ◽  
Pengfei Jin ◽  
Yongmei Kuang
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Photoelectron Spectroscopy ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Light Irradiation ◽  
Electron Hole ◽  
Magnetic Stirring ◽  
Degradation Activity

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.

Plasmon-Induced Photodegradation of Toxic Pollutants with Ag/AgI/Bi2WO6 under Visible-Light Irradiation

2013 ◽  
Vol 807-809 ◽  
pp. 1534-1542 ◽  
Author(s):  
Ming Sheng Gui ◽  
Peng Fei Wang ◽  
Miao Miao Tang ◽  
Dong Yuan
Keyword(s):  
Surface Plasmon Resonance ◽  
Visible Light ◽  
Surface Plasmon ◽  
Visible Light Irradiation ◽  
Plasmon Resonance ◽  
Photogenerated Electron ◽  
Light Irradiation ◽  
Ag Nps ◽  
Electron Hole ◽  
Band Position

The Ag/AgI/Bi2WO6photocatalysts were successfully synthesized by deposition-precipitation and photoreduction methods. The catalyst showed high and stable photocatalytic activity for the degradation of the RhB under visible light irradiation (λ>400 nm). On the basis of a new plasmonic photocatalytic mechanism, the photogenerated electron-hole pairs are formed in Ag nanoparticles (NPs) due to surface plasmon resonance under visible-light irradiation. Then, the photoexcited electrons at the Ag NPs are injected into AgI. On the other hand, the band position shows that AgI and Bi2WO6have the matching band potentials in the AgI/Bi2WO6heterostructure composites. So the photoexcited electrons is ultimately transfer to the Bi2WO6conduction band (CB), photo-induced holes (hVB+) is transfer to the AgI valence band (VB) and the simultaneous transfer to compensative electrons from I-to the Ag NPS. This the result indicates that the high photosensitivity of noble metal Ag NPs due to surface plasmon resonance, which is not only improve the photocatalytic performance, but also offer a new idea for preparation of new photocatalysts .

scholarly journals Highly efficient zinc oxide-carbon nitride composite photocatalysts for degradation of phenol under UV and visible light irradiation

2018 ◽  
Vol 14 (1-2) ◽  
pp. 159-163 ◽  
Author(s):  
Faisal Hussin ◽  
Hendrik Oktendy Lintang ◽  
Siew Ling Lee ◽  
Leny Yuliati
Keyword(s):  
Zinc Oxide ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Carbon Nitride ◽  
Separation Efficiency ◽  
Visible Region ◽  
Light Irradiation ◽  
Composite Photocatalyst ◽  
Optimum Content ◽  
Composite Photocatalysts

In order to utilize solar light in an efficient way, a good photocatalyst shall absorb both UV and visible light. In this study, a series of composite photocatalyst consisting of zinc oxide (ZnO) and carbon nitride (CN) was successfully prepared through a physical mixing method. The ZnO is an ultraviolet (UV)-based photocatalyst, while the CN is known as a visible light-driven photocatalyst. The effect of zinc to carbon mol ratio (Zn/C) towards the properties and photocatalytic activities was investigated. X-ray diffraction (XRD) patterns revealed that the prepared ZnO-CN composite photocatalysts composed of wurtzite ZnO and graphitic CN. The presence of ZnO and CN made the composites have absorption at both UV and visible region, suggesting the potential application as photocatalysts under both UV and visible light. Fluorescence studies revealed that all ZnO-CN composites showed emission peaks at 445 and 460 nm when excited at 273 nm, but with lower intensity as compared to those of the CN. The lower emission intensity suggested the role of ZnO to reduce the charge recombination and improve the charge separation on the CN. The ZnO-CN composites were further evaluated for photocatalytic degradation of phenol. The amount of degraded phenol was determined by a gas chromatography, in which a flame ionization detector was used in this study (GC-FID). The composite photocatalyst with an optimum content of 1% Zn/C gave almost 1.15 times higher activity than the CN under visible light irradiation. On the other hand, the composite photocatalyst with an optimum content of 50% Zn/C showed 2.6 times higher activity than the CN under UV light. The improved photocatalytic efficiency on the ZnO-CN composite photocatalysts was caused by the synergic effect between ZnO and CN. The ZnO would boost the separation efficiency of photogenerated electrons on the CN, while the CN would enable ZnO to absorb visible light region as the ZnO-CN composites. 

pH-Controlled photocatalytic abatement of RhB by an FeWO4/BiPO4 p–n heterojunction under visible light irradiation

2019 ◽  
Vol 43 (44) ◽  
pp. 17241-17250
Author(s):  
Nithya Mahendran ◽  
Sathya Udayakumar ◽  
Keerthi Praveen
Keyword(s):  
Electric Field ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Separation Efficiency ◽  
Light Irradiation ◽  
The Novel ◽  
Electron Hole ◽  
Ph Controlled

The novel FeWO4/BiPO4 heterojunction generates an inner electric field to promote electron–hole separation efficiency and is a proficient photocatalyst.

A simple method to synthesise Ag-doped TiO2 photocatalysts with different Ag0:Ag2O atomic ratios for enhancing visible-light photocatalytic activity

2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Visible Region ◽  
Light Irradiation ◽  
Electron Hole ◽  
X Ray

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.

scholarly journals Synthesis of WO3/Ag3VO4 photocatalyst applying for the treatment of amoxicillin antibiotics under visible light

2021 ◽  
Vol 63 (11) ◽  
pp. 75-79
Author(s):  
Thi Thu Phuong Tran ◽  
◽  
My Ngoc Tram Dinh ◽  
Thi Yen Nhi Pham ◽  
Vu Ngoc Mai Nguyen ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Adsorption Capacity ◽  
Visible Light Irradiation ◽  
Photogenerated Electron ◽  
Reflectance Spectra ◽  
Light Irradiation ◽  
Electron Hole ◽  
Efficient Separation ◽  
Highly Active

In this paper, WO3/Ag3VO4 photocatalysts were successfully synthesised at various Ag3VO4/WO3 mole ratiosof5, 10, 15, and 20%(WA-x). Ultraviolet-visiblediffuse reflectance spectra (UV-Vis-DRS) indicated that the adsorption capacity of WA-10 (10% Ag3VO4/WO3 mole ratios) under visible light was higher than that of other materials. The photocatalytic properties of obtained materials were investigated by degradation of the antibiotic AMX under visible light irradiation. The degradation conversation of AMX had gotten to about 79.86% in WA-10 after a reaction of three hours. WO3/Ag3VO4 materials were highly active than WO3 and Ag3VO4 with an increase in photocatalytic activity of WO3/Ag3VO4 that can be attributed to the efficient separation of photogenerated electron-hole pairs.

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 ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Synergistic Effect ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Separation Efficiency ◽  
Light Irradiation ◽  
Electron Hole ◽  
Dye Pollutants ◽  
High Separation ◽  
Co Doped

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.

scholarly journals Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Carbon Cloth ◽  
Electron Hole ◽  
Step Process ◽  
Photogenerated Electrons ◽  
Rapid Transfer ◽  
Visible Light Photocatalytic

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.

scholarly journals Synthesis, Analysis, and Testing of BiOBr-Bi2WO6Photocatalytic Heterojunction Semiconductors

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangchao Meng ◽  
Zisheng Zhang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Degradation Process ◽  
Light Irradiation ◽  
Enhancement Effect ◽  
Electron Hole ◽  
Experimental Conditions ◽  
Synthesis Conditions ◽  
Optimum Synthesis ◽  
Photocatalytic Activities

In photocatalysis, the recombination of electron-hole pairs is generally regarded as one of its most serious drawbacks. The synthesis of various composites with heterojunction structures has increasingly shed light on preventing this recombination. In this work, a BiOBr-Bi2WO6photocatalytic heterojunction semiconductor was synthesized by the facile hydrothermal method and applied in the photocatalytic degradation process. It was determined that both reaction time and temperature significantly affected the crystal structure and morphologies of the photocatalysts. BiOBr (50 at%)-Bi2WO6composites were prepared under optimum synthesis conditions (120°C for 6 h) and by theoretically analyzing the DRS results, it was determined that they possessed the suitable band gap (2.61 eV) to be stimulated by visible-light irradiation. The photocatalytic activities of the as-prepared photocatalysts were evaluated by the degradation ofRhodamine B (RhB)under visible-light irradiation. The experimental conditions, including initial concentration, pH, and catalyst dosage, were explored and the photocatalysts in this system were proven stable enough to be reused for several runs. Moreover, the interpreted mechanism of the heterojunction enhancement effect proved that the synthesis of a heterojunction structure provided an effective method to decrease the recombination rate of the electron-hole pairs, thereby improving the photocatalytic activity.

Construction of Z-Scheme Bi3TaO7/Zn0.5Cd0.5S composites with high-efficiency for levofloxacin degradation under visible light irradiation

2021 ◽  
Author(s):  
Jingjing Xu ◽  
Yang liu ◽  
xueping li ◽  
Mindong Chen
Keyword(s):  
Visible Light ◽  
Hydrothermal Method ◽  
Visible Light Irradiation ◽  
High Efficiency ◽  
Light Irradiation ◽  
In Situ Growth ◽  
Composite Photocatalysts ◽  
Photocatalytic Activities

Direct Z-scheme Bi3TaO7/Zn0.5Cd0.5S composite photocatalysts were successfully prepared via an in-situ growth hydrothermal method. The photocatalytic activities of composites were investigated by the degradation of levofloxacin under visible light. And...

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