scholarly journals Preparation of Ag3PO4/TiO2(B) Heterojunction Nanobelt with Extended Light Response and Enhanced Photocatalytic Performance

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6987
Author(s):  
Yong Li ◽  
Yanfang Liu ◽  
Mingqing Zhang ◽  
Qianyu Zhou ◽  
Xin Li ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Light Response ◽  
Light Quantum ◽  
Electron Hole ◽  
Composite Photocatalyst ◽  
Tio2 Nanobelts ◽  
Ag3po4 Nanoparticles

Photocatalytic degradation, as an emerging method to control environmental pollution, is considered one of the most promising environmental purification technologies. As Tibet is a region with some of the strongest solar radiation in China and even in the world, it is extremely rich in solar energy resources, which is ideal for applying photocatalytic technology to its ecological environment protection and governance. In this study, Na2Ti3O7 nanobelts were prepared via a hydrothermal method and converted to TiO2∙xH2O ion exchange, which was followed by high-temperature calcination to prepare TiO2(B) nanobelts (“B” in TiO2(B) means “Bronze phase”). A simple in situ method was used to generate Ag3PO4 particles on the surface of the TiO2 nanobelts to construct a Ag3PO4/TiO2(B) heterojunction composite photocatalyst. By generating Ag3PO4 nanoparticles on the surface of the TiO2(B) nanobelts to construct heterojunctions, the light absorption range of the photocatalyst was successfully extended from UV (ultraviolet) to the visible region. Furthermore, the recombination of photogenerated electron–hole pairs in the catalyst was inhibited by the construction of the heterojunctions, thus greatly enhancing its light quantum efficiency. Therefore, the prepared Ag3PO4/TiO2(B) heterojunction composite photocatalyst greatly outperformed the TiO2(B) nanobelt in terms of photocatalytic degradation.

AgBrO3/Few-Layer g-C3N4 Composites: A Visible-Light-Driven Photocatalyst for Tetracycline Degradation

2020 ◽  
Vol 20 (6) ◽  
pp. 3424-3431 ◽  
Author(s):  
Jia-Rui Zhang ◽  
Xiang-Feng Wu ◽  
Xin Tong ◽  
Chen-Xu Zhang ◽  
Hui Wang ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Degradation Mechanism ◽  
Photogenerated Electron ◽  
Degradation Process ◽  
Active Species ◽  
Light Illumination ◽  
Electron Hole ◽  
Composite Photocatalyst ◽  
And Migration

The AgBrO3/few-layer g-C3N4 composite photocatalyst has been developed via an in-situ synthetic method. The structure, morphology, light response range, separation and migration efficiency of the photogenerated electron–hole pairs and element valence state of the as-obtained samples have been characterized. The tetracycline was used to discuss the photocatalytic activities of the samples. The photocatalytic degradation mechanism of the as-obtained composites was also researched. The analysis results show that the photocatalytic degradation property of the asobtained composite photocatalyst appears to the tendency of first increasing and then decreasing with increasing the amount of AgBrO3 under visible light illumination. When the mass ratio of AgBrO3 to g-C3N4 is 4:3, in 60 min, the photocatalytic degradation efficiency of the as-obtained composites reaches the maximum of 79%. It is 37% and 45% higher than that of pure AgBrO3 and g-C3N4, respectively. Moreover, the separation and migration efficiency of the photogenerated electron–hole pairs of the as-prepared composites are also enhanced. In addition, superoxide radicals and holes are the dominant active species during the photocatalytic degradation process.

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 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 Photocatalytic Adsorption Synergistic Degradation of Tetracycline by Z-scheme Bi2WO6/ZIF-8

2021 ◽  
Author(s):  
Xiaojun Dai ◽  
sheng feng ◽  
Wei Wu ◽  
Yun Zhou ◽  
Zhiwei Ye ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Photogenerated Electron ◽  
Utilization Efficiency ◽  
Electron Hole ◽  
Effects Of Ph ◽  
Growth Method ◽  
Synergistic Degradation ◽  
First Time

Abstract In this paper, in order to improved the photocatalytic activity of Bi2WO6, Bi2WO6 and ZIF-8 were successfully combined by in-situ growth method for the first time. The addition of ZIF-8 effectively inhibited the recombination of photogenerated electron hole pairs and further improved the electron utilization efficiency, and superoxide anion was introduced to greatly improve the photocatalytic activity. The performance of Bi2WO6/ZIF-8 in the photodegradation of tetracycline (TC) was studied under different conditions of proportions of ZIF-8, dosage of catalyst and concentration of TC. The results indicated that B/Z/5/1 (10mg) had the best photocatalytic activity, and 97.8% of TC (20mg/L) could be degraded in 80 minutes under UV light, the rate constant (k) for TC degradation was almost 3 times that of Bi2WO6. The effects of pH, HA and inorganic anions on the degradation of TC were studied in simulated real water. Further, B/Z/5/1 could be reutilized up to five cycles without reduction of efficiency and catalysis performance. Therefore, Bi2WO6/ZIF-8 heterojunction composite material can be utilized as an efficient photocatalyst for remediation of environmental pollution.

scholarly journals Ag3PO4 Deposited on CuBi2O4 to Construct Z-Scheme Photocatalyst with Excellent Visible-Light Catalytic Performance Toward the Degradation of Diclofenac Sodium

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 959 ◽  
Author(s):  
Xiaojuan Chen ◽  
Chunmu Yu ◽  
Runliang Zhu ◽  
Ning Li ◽  
Jieming Chen ◽  
...  
Keyword(s):  
Degradation Rate ◽  
Performance Enhancement ◽  
Separation Efficiency ◽  
Diclofenac Sodium ◽  
Sodium Stearate ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
Electron Hole ◽  
In Situ Deposition

CuBi2O4/Ag3PO4 was synthesized through a combination of hydrothermal synthesis and an in situ deposition method with sodium stearate as additives, and their textures were characterized with XRD, XPS, SEM/HRTEM, EDS, UV-Vis, and PL. Then, the photodegradation performance of CuBi2O4/Ag3PO4 toward the degradation of diclofenac sodium (DS) was investigated, and the results indicate that the degradation rate of DS in a CuBi2O4/Ag3PO4 (1:1) system is 0.0143 min−1, which is 3.6 times that in the blank irradiation system. Finally, the photocatalytic mechanism of CuBi2O4/Ag3PO4 was discussed, which follows the Z-Scheme theory, and the performance enhancement of CuBi2O4/Ag3PO4 was attributed to the improved separation efficiency of photogenerated electron–hole pairs.

Synthesis, characterization, and application of polypyrrole/TiO2 composites in photocatalytic processes: A review

2020 ◽  
pp. 096739112094948 ◽  
Author(s):  
Suélen M Amorim ◽  
Gabriel Steffen ◽  
Joel MN de S Junior ◽  
Claiton Z Brusamarello ◽  
Ana P Romio ◽  
...  
Keyword(s):  
Noble Metals ◽  
In Situ Polymerization ◽  
Electrochemical Polymerization ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Band Gap Energy ◽  
Electron Hole ◽  
Photoexcited Electron ◽  
New Class ◽  
Photocatalytic Processes

Hybrid materials composed of semiconductor oxide metals and conducting polymers have been highlighted as a new class of materials, with superior properties compared to their pure constituents. Among the studied composites to photocatalytic applications, the hybrids of titanium dioxide (TiO2) and polypyrrole (PPy) are promising due to several advantages over the pure TiO2 nanoparticles. The PPy/TiO2 composite has been effectively synthetized by chemical polymerization methods as in situ polymerization, photopolymerization, electrochemical polymerization, and molecular imprinting polymerization (MIP). All the cited methods appear to be effective in reducing the band gap energy, which suggests an increase in the formation of photoexcited electron-hole pairs and, consequently, an improvement of the light absorption in the visible region (400–700 nm). In addition, the doping of PPy/TiO2 with noble metals improves the separation of charges in the semiconductor particle, inhibiting the recombination of photogenerated electron-hole pairs. All advantages are evidenced by the characterization results of SEM, TEM, HRTEM, UV-vis DRS, FTIR, XRD, PL, TGA and electrical properties. Finally, results from literature present that PPy/TiO2 composites have better photocatalytic activity than the pure TiO2, being an alternative photocatalyst promising for visible light applications. Thus, this work presents a review of the synthesis, characterization, and application of PPy/TiO2 composites in the photocatalytic processes.

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.

scholarly journals Synthesis and Characterization of Amorphous Molybdenum Sulfide (MoSx)/CdIn2S4 Composite Photocatalyst: Co-Catalyst Using in the Hydrogen Evolution Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1455
Author(s):  
Qi Li ◽  
Wanli Liu ◽  
Xuejian Xie ◽  
Xianglong Yang ◽  
Xiufang Chen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Molybdenum Sulfide ◽  
Electron Hole ◽  
Composite Photocatalyst ◽  
Co Catalyst ◽  
Pair Separation ◽  
Electron Hole Pair

Co-catalyst deposition is used to improve the surface and electrical properties of photocatalysts. In this work, MoSx/CdIn2S4 nanocomposites were prepared by a facile hydrothermal and photodeposition route. The basic crystalline phases and morphology of the as-prepared samples were determined, and these results showed that MoSx was tightly anchored onto CdIn2S4 by sharing the same S atom. In the hydrogen production experiments, MoSx/CdIn2S4-40 displayed the optimal photocatalytic hydrogen production yield in 4 h. The H2 evolution rate reached 2846.73 μmol/g/h, which was 13.6-times higher than that of pure CdIn2S4. Analyzing the photocatalytic enhancement mechanisms revealed that this unique structure had a remarkable photogenerated electron-hole pair separation efficiency, rapid charge carrier transfer channels, and more abundant surface reaction sites. The use of co-catalyst (MoSx) greatly improved the photocatalytic activity of CdIn2S4.

Synthesis of Cu2(OH)PO4 superstructures with NIR-laser enhanced photocatalytic activity

2020 ◽  
Vol 13 (03) ◽  
pp. 2050015 ◽  
Author(s):  
Lu Cheng ◽  
Nuo Yu ◽  
Yan Zhang ◽  
Zhun Shi ◽  
Haifeng Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Near Infrared ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Photothermal Effect ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
Light Group ◽  
Nir Laser

The development of photocatalysts with wide UV-Vis-near-infrared (NIR) photoabsorption has received tremendous interest for utilizing sunlight efficiently. In this work, Cu2(OH)PO4 superstructures are prepared by a simple hydrothermal route, and they have strong bandgap absorption in UV-Visible region and a distinctive plasmon resonance absorption in NIR region. Under the synergetic illumination of visible light and 980[Formula: see text]nm laser (3.0[Formula: see text]W[Formula: see text]cm[Formula: see text]), Cu2(OH)PO4 superstructures can degrade 89.2% MB with the elevated temperature ([Formula: see text]51∘C) of solution, which is higher than that from visible light group (50.0%), laser group (16.4%), and visible-light/exterior-heating group (62.5%, same temperature at [Formula: see text]51.0∘C). These facts reveal that Cu2(OH)PO4 superstructures exhibit NIR-laser enhanced photocatalytic activity, which not only comes from the photothermal effect-induced temperature elevation, but also mainly results from the increased production of photogenerated electron-hole pairs by NIR-laser. Therefore, Cu2(OH)PO4 superstructures can act as efficient photocatalyst with NIR-laser enhanced photocatalytic activity.

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