Preparation of Bi/Bi2MoO6 Plasmonic Photocatalyst with High Photocatalytic Activity Under Visible Light Irradiation

NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850127 ◽  
Author(s):  
Chentao Zou ◽  
Zhiyuan Yang ◽  
Mengjun Liang ◽  
Yunpeng He ◽  
Yun Yang ◽  
...  

Bi metal deposited on Bi2MoO6 composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using NaBH4 as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of Bi/Bi2MoO6 composite to RhB is 10.8 times that of Bi2MoO6, and the degradation rate constant of BPA is 6.9 times of that of Bi2MoO6. Nitrogen absorption–desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of Bi/Bi2MoO6 composites. The higher charge transfer efficiency of Bi/Bi2MoO6 is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jing Yan ◽  
Xiaojuan Li ◽  
Bo Jin ◽  
Min Zeng ◽  
Rufang Peng

A series of TiO2, TiO2/Pd, and TiO2/PdO hollow sphere photocatalysts was successfully prepared via a combination of hydrothermal, sol-immobilization, and calcination methods. The structure and optical properties of the as-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Telleranalysis, Barrett-Joyner-Halenda measurement, and UV-Vis diffuse reflectance spectroscopy. The photocatalysis efficiencies of all samples were evaluated through the photocatalytic degradation of rhodamine B under visible light irradiation. Results indicated that TiO2/PdO demonstrated a higher photocatalytic activity (the photocatalytic degradation efficiency could reach up to 100% within 40 min) than the other samples and could maintain a stable photocatalytic degradation efficiency for at least four cycles. Finally, after using different scavengers, superoxide and hydroxyl radicals were identified as the primary active species for the effectiveness of the TiO2/PdO photocatalyst.


2018 ◽  
Vol 54 (2A) ◽  
pp. 164
Author(s):  
Nguyen Tan Lam

This paper presents a study on preparation of sulfur doped titanium dioxide using potassium fluorotitanate and sodium sulfate as precursors. The obtained results indicated that the doped TiO2 exhibited very high photocatalytic activity for degradation of methylene blue even under visible light. The increasing in the added sulfur amounts led to significantly increase in the degradation of methylene blue. When the S/TiO2 mole ratios increased from 10 to 25%, the degradation of methylene blue under compact light increased from 30.87% to 67.06%, respectively.


NANO ◽  
2016 ◽  
Vol 11 (01) ◽  
pp. 1650001 ◽  
Author(s):  
Lei Shi ◽  
Da Chen ◽  
Wenting Xie ◽  
Jing Zhang ◽  
Guangxing Ping ◽  
...  

In this work, thermally exfoliated graphene nanosheets (GNS) were employed to prepare novel Ag3PO4–GNS composite photocatalysts by a facile chemical precipitation approach. The as-prepared Ag3PO4–GNS composite photocatalysts were characterized by X-ray diffraction (XRD) pattern, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman spectroscopy, thermogravimetric (TG) analysis, ultraviolet-visible diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectra. It was found that the Ag3PO4 particles were well deposited on the surfaces of GNS. Compared with bare Ag3PO4 and Ag3PO4–rGO composite, the Ag3PO4–GNS composite exhibited enhanced photocatalytic activity for the photodegradation of rhodamine B (RhB) under visible light irradiation. The photocatalytic degradation rate of Ag3PO4–GNS composite was 1.7 times that of bare Ag3PO4 and about 1.3 times that of Ag3PO4–rGO for the degradation of RhB. Furthermore, the photocatalytic stability of Ag3PO4–GNS composite was also greatly enhanced. This enhanced photocatalytic activity and stability could be ascribed to the positive synergetic effects between the Ag3PO4 particles and GNS sheets, which could provide a greater number of active adsorption sites, suppress charge recombination and reduce the serious photocorrosion of Ag3PO4. Moreover, the photocatalytic degradation of RhB over Ag3PO4–GNS composites was also optimized, suggesting that the optimal amount of GNS in the composites was 11.4[Formula: see text]wt.%. This work shows a great potential of Ag3PO4–GNS composite for environmental treatment of organic pollutants.


2020 ◽  
Vol 4 (2) ◽  
pp. 54 ◽  
Author(s):  
Rina Heu ◽  
Mohamed Ateia ◽  
Dion Awfa ◽  
Patiparn Punyapalakul ◽  
Chihiro Yoshimura

Nanocomposites of UiO-66 and graphene oxide (UiO-66_GO) were prepared with different GO contents by a one-step hydrothermal method, and their photocatalytic activities for the degradation of carbamazepine (CBZ) were investigated under ranges of GO loading, catalyst dose, initial pollutant concentration, and solution pH. The UiO-66_GO nanocomposites showed photocatalytic rate constant up to 0.0136 min−1 for CBZ degradation and its high overall removal efficiency (>90%) in 2 h. The photocatalytic rate constant over the UiO-66_GO nanocomposite was about 2.8 and 1.7 times higher than those over pristine GO and UiO-66, respectively. The enhancement of photocatalytic activity by GO was attributed to increased surface area and porosity, improved light absorption, and narrowed band gap. The composite also showed substantial recyclability and stability over five consecutive cycles of photocatalytic degradation. The experimental results indicated that O2●− and OH● are the responsible radicals for photocatalytic degradation, which helped us propose a photocatalytic mechanism for the enhanced CBZ photodegradation. This work provides a reference for the development of GO-based composite photocatalysts and expands the application of UiO-66 as a photocatalyst for the degradation of persistent micropollutants in water.


RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101105-101114 ◽  
Author(s):  
H. Ait Ahsaine ◽  
A. El jaouhari ◽  
A. Slassi ◽  
M. Ezahri ◽  
A. Benlhachemi ◽  
...  

BWO and Lu-BWO were synthesized by coprecipitation method. Lu-BWO sample exhibits the highest visible-light-responsive photocatalytic performance for the degradation of MB. h+ and ˙O2− are the main active species in the photocatalytic degradation.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Zhiqing Yong ◽  
Jian Ren ◽  
Huilin Hu ◽  
Peng Li ◽  
Shuxin Ouyang ◽  
...  

Novel graphitic carbon nitride/KTaO3(g-C3N4/KTaO3) nanocomposite photocatalysts have been successfully synthesized via a facile and simple ultrasonic dispersion method. Compared to either g-C3N4or KTaO3, the composite photocatalysts show significantly increased photocatalytic activity for degradation of Rhodamine B (RhB) under visible light irradiation. The increased photocatalytic performance of the composite could be attributed to the enhanced photogenerated charge carrier separation capacity. Moreover, it is observed that∙O2-is the main active species in the photocatalytic degradation of RhB using the g-C3N4/KTaO3composite photocatalysts.


NANO ◽  
2016 ◽  
Vol 11 (09) ◽  
pp. 1650105 ◽  
Author(s):  
Xiaoting Meng ◽  
Xiaofang Cheng ◽  
Dongrong Zhuang ◽  
Shaogui Yang ◽  
Cheng Sun

A series of Ag3PO4/BiOCOOH composite photocatalysts have been successfully synthesized by a simple in situ ion precipitation method. The crystallinity, morphology, microstructure, composition and optical property were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectrum (EDS), Fourier transform infrared spectrometer (FT-IR), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectrophotometer (DRS). The as-prepared catalysts exhibited excellent photocatalytic activity for the degradation of RhB and MB under visible light irradiation, the 2:1 Ag3PO4/BiOCOOH exhibited the best photocatalytic activity. By adding different free radical scavengers, the catalytic mechanism was discussed. In the process of degradation of RhB, holes (h[Formula: see text] is the main active species, [Formula: see text]O[Formula: see text] played a certain active role, [Formula: see text]OH played a small role. In the process of degradation MB, holes (h[Formula: see text] is the main active species too, [Formula: see text]O[Formula: see text] also played a certain active role, [Formula: see text]OH almost does not work.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Chunbei Wu ◽  
Chuxin Zhou ◽  
Yuanyuan Chen ◽  
Zhigang Peng ◽  
Jun Yang ◽  
...  

A Bi-BiOBr/BiPO4 heterojunction structure was successfully synthesized via a two-step solvothermal method with ethylene glycol as a reducer. Little BiPO4 irregular polyhedrons and little metal Bi spherical nanoparticles were uniformly dispersed on the surface of BiOBr nanosheets with intimate contact and formed a heterojunction structure between BiPO4 and BiOBr. It was found that Bi-BiOBr/BiPO4 had a significant improvement in photocatalytic performance for RhB degradation compared to bare BiOBr and BiPO4. The photocatalytic degradation rate constant of 0.2-Bi/BiOBr/BiPO4 was 1.44 h-1, which was 3.8 times and 14.2 times more than that of bare BiOBr and BiPO4, respectively. This is attributed to the formation of a ternary heterojunction, which benefits the separation of photogenerated electron-hole pairs. Furthermore, with the introduction of metal Bi, the SPR effect of metal Bi can effectively improve the absorption ability of Bi-BiOBr/BiPO4 photocatalyst, resulting in enhanced photoactivity. In this work, the mechanism of photocatalytic degradation was studied by using the photochemical technique and the capture experiment of active species, and it was revealed that h+ and ⋅O2- played a major role in the photocatalytic process.


Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 729 ◽  
Author(s):  
Li Guo ◽  
Xuanxuan Han ◽  
Kailai Zhang ◽  
Yuanyuan Zhang ◽  
Qiang Zhao ◽  
...  

Photocatalytic nitrogen fixation and pollutants degradation at ambient temperature and pressure as a clean and efficient means represents a sustainable direction. In this paper, novel two-dimensional (2D) ZnIn2S4/2D BiOCl (ZIS/BOC) nanosheets heterostructures were successfully synthesized by in-situ solvothermal techniques. XPS and TEM results showed the formation of heterostructure. The photocatalytic properties of these materials were further studied by degradating phenol and nitrogen fixation under visible light irradiation. In particular, heterostructure obtained with a mass ratio of 0.5 wt % of ZnIn2S4 had a good application prospect and can achieve 77.4% phenol degradation rate within 6 h and a rate of ammonium production of 14.6 µmol∙gcat−1·h−1. The reaction rate of 0.5 wt % ZIS/BOC heterostructure exhibited 8.6 and 2.6 times relative to BiOCl for the degradation of phenol and nitrogen fixation, respectively. The enhanced photocatalytic activity was attributed to the collaboration of low recombination rate of photo-generated carriers and enhanced visible light absorption. Based on capture experiments and electron spin resonance (ESR) techniques, the main active species that may appear in photocatalytic systems were explored, and the corresponding photocatalytic mechanism was also proposed appropriately. This strategy will open up new ideas for the design and manufacture of more energy-efficient materials with high photocatalytic activity.


2018 ◽  
Vol 5 (4) ◽  
pp. 879-896 ◽  
Author(s):  
Dipti Prava Sahoo ◽  
Sulagna Patnaik ◽  
Dharitri Rath ◽  
K. M. Parida

The SPR effect of monodisperse Ag nanoparticles in Ag@Ag3VO4/ZnCr LDH heterostructures exhibits high photocatalytic activity towards evolution of O2 and oxidation of phenol.


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