Visible light-induced bactericidal properties of a novel thiophene-based linear conjugated polymer/TiO2 heterojunction

2021 ◽  
Author(s):  
Juan Du ◽  
Renming Liu ◽  
Enwei Zhu ◽  
Haiyong Guo ◽  
Zhiyi Li ◽  
...  
Keyword(s):  
Visible Light ◽  
Conjugated Polymer ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Intrinsic Defects ◽  
Bactericidal Properties

The low utilization of visible light and the fast recombination of photogenerated electron-hole pairs are the two intrinsic defects that have hindered the antibacterial applications of TiO2. The addition of...

scholarly journals Using Gd-Enhanced β-NaYF4:Yb,Er Fluorescent Nanorods Coupled to Reduced TiO2 for the NIR-Triggered Photocatalytic Inactivation of Escherichia coli

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 184
Author(s):  
Huang Zhou ◽  
Fengjiao He
Keyword(s):  
Escherichia Coli ◽  
Visible Light ◽  
Near Infrared ◽  
Green Light ◽  
Photogenerated Electron ◽  
Light Illumination ◽  
Electron Hole ◽  
Flight Mass Spectrometry ◽  
Nir Light ◽  
Bactericidal Properties

β-NaYF4:Yb,Er,Gd fluorescent nanorods were successfully coupled to a reduced TiO2 (UCNPs@R-TiO2) nanocomposite and applied to visible-light catalytic sterilization under 980 nm near-infrared (NIR) light illumination. The UCNPs (β-NaYF4:Yb,Er,Gd) absorb the NIR light and emit red and green light. The visible light can be absorbed by the R-TiO2 (Eg = 2.8 eV) for the photocatalytic reaction. About 98.1% of Escherichia coli were effectively killed upon 12 min of NIR light irradiation at a minimum inhibitory concentration (MIC) of 40 μg/mL UCNPs@R-TiO2 nanocomposite. The bactericidal properties were further evaluated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. We found that the high bactericidal activity was due to the synergistic effect between the UCNPs and R-TiO2. Moreover, the UCNPs show excellent upconversion luminance properties, and the introduction of visible-light-absorbed R-TiO2 nanoparticles (2.8 eV) was conducive to the efficient separation and utilization of photogenerated electron-hole pairs.

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 Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2206
Author(s):  
Gaoqian Yuan ◽  
Gen Zhang ◽  
Kezhuo Li ◽  
Faliang Li ◽  
Yunbo Cao ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Bimetallic Nanoparticles ◽  
Resonance Effect ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Pt Nanoparticles ◽  
Electron Hole

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.

One-Step Hydrothermal Synthesis of Bi2S3-TiO2-RGO Composites with Enhanced Visible Light Photocatalytic Activities

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850051 ◽  
Author(s):  
Yanan Li ◽  
Zhongmin Liu ◽  
Yaru Li ◽  
Yongchuan Wu ◽  
Jitao Chen ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Photogenerated Electron ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Photocatalytic Ability ◽  
Transmission Electron ◽  
Light Region ◽  
Infrared Spectrometer ◽  
One Step

The Bi2S3-TiO2-RGO composites were synthesized by a facile one-step hydrothermal method and applied for the photocatalytic degradation of Rhodamine B (Rh B) under the visible light. The Bi2S3-TiO2-RGO composites were characterized by transmission electron microscopy, X-ray diffraction, Raman and Fourier transform infrared spectrometer. The results indicated that the Bi2S3-TiO2-RGO composites were successfully prepared, and Ti-O-C and S-C bonds were existing among Bi2S3, TiO2 as well as RGO. Furthermore, the photocatalytic ability of Bi2S3-TiO2-RGO composites was excellent under visible light due to its responding to the whole visible light region, low recombination rate of photogenerated electron–hole pairs and relatively negative conduction band. Rh B photocatalytic degradation rate was 99.5% after 50[Formula: see text]min and still could reach 98.4% after five cycles. Finally, a formation mechanism as well as a photocatalytic mechanism of Bi2S3-TiO2-RGO composites were proposed based on the experimental results.

scholarly journals Synthesis and characterization of Z-scheme heterostructure CoWO4/g-C3N4 as a visible-light photocatalyst for removal of organic pollutant

2021 ◽  
Vol 10 (2) ◽  
pp. 59-63
Author(s):  
Hai Pham Viet ◽  
Anh Dao Thi Ngoc ◽  
Viet Nguyen Minh ◽  
Ha Tran Thi Viet ◽  
Dang Do Van ◽  
...  
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
High Performance ◽  
Organic Pollutant ◽  
Photogenerated Electron ◽  
Morphological Properties ◽  
Electron Hole ◽  
Visible Light Photocatalyst ◽  
Photocatalytic Activities

In this study, direct Z–scheme heterostructure CoWO4/g-C3N4 was synthesized by a facile hydrothermal method. The structural, morphological properties of the prepared samples were characterised by XRD, SEM, UV–Vis and PL measurements. The as-obtained heterostructure CoWO4/g-C3N4 exhibited enhanced photocatalytic activities toward the degradation of Rhodamine B under visible light irradiation with 92% Rhodamine B removal after 80 minutes irritation, which exceeded pristine g-C3N4 and CoWO4. The enhanced photocatalytic performance ascribed to interfacial contact between g-C3N4 and CoWO4, thus further inhibiting the recombination of photogenerated electron/hole pairs. It is anticipated that the construction of Z–scheme heterostructure CoWO4/g-C3N4 is an effective strategy to develop high-performance photocatalysts for the degradation of organic pollutants in water.

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 .

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 ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Er Doped

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

scholarly journals Synthesis and characterization of black TiO2/graphene composites with enhanced photocatalysis

2020 ◽  
Author(s):  
Zhaoqing Li ◽  
Zhufeng Liu ◽  
Xiao Yang ◽  
Peng Chen ◽  
Lei Yang ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
Attractive Potential ◽  
Electron Hole ◽  
Hole Recombination

Abstract According to the composite design, a series of black TiO2/graphene composites were synthesized to improve its photocatalytic activity. TiO2 is generated in situ on the surface of graphene by a facile sol-gel method. The combination of graphene and TiO2 was beneficial for eliminating the opportunity of photogenerated electron-hole recombination due to the excellent conductivity of graphene. In the subsequent hydrogenation process, the self-doping Ti3+ was introduced accompanied by the crystallization of amorphous TiO2. The narrowed bandgap caused by self-doping Ti3+ enhanced the visible light absorption and make the composites appear black. Both of them improved the photocatalytic performance of the synthesized black TiO2/graphene composites. The band structure of the composite was analyzed by valence band XPS, revealing the reason for the high visible light catalytic performance of the composite. The results proved that the black TiO2/graphene composites synthesized show attractive potential for applications in environmental and energy issues.

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.

Construction of a novel Cu2(OH)3F/g-C3N4 heterojunction as a high-activity Fenton-like catalyst driven by visible light

2021 ◽  
Author(s):  
Lifen Wang ◽  
Yinjun Lin ◽  
Wenting Guo ◽  
Yuanyuan Yang ◽  
Ruiqin Zhang ◽  
...  
Keyword(s):  
Visible Light ◽  
High Activity ◽  
Photogenerated Electron ◽  
Hole Pair ◽  
Competitive Effect ◽  
Electron Hole ◽  
Fenton Reagents ◽  
Pair Separation ◽  
Electron Hole Pair

Inhibiting the competitive effect of O2 in copper-based Fenton reagents and improving the photogenerated electron–hole pair separation of g-C3N4 are the focus of current research.

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