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.

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.

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.

Synthesis and High Visible Light Photocatalytic Activity of Ternary Brookite-g-C3N4-BiOBr Composite

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050045
Author(s):  
Ning Liu ◽  
Huidong Xie ◽  
Jie Li ◽  
Yajuan Zhao ◽  
Na Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Rhodamine B ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Photocurrent Density ◽  
Electron Hole ◽  
Degradation Ratio ◽  
Loading Amount ◽  
Visible Light Photocatalytic

Brookite TiO2 was synthesized by a hydrothermal method, g-C3N4 was prepared by a pyrolytic method, brookite/g-C3N4 composites were prepared by a calcining method, and brookite/g-C3N4/BiOBr ternary composites were prepared by loading BiOBr on the surface of brookite/g-C3N4. XRD and XPS analysis of the composites confirmed the formation of brookite TiO2/g-C3N4/BiOBr. SEM and TEM results confirmed the as-prepared composites were nanosized. The optimum loading amount of BiOBr was 30%. The photocatalytic results showed that the brookite/g-C3N4/30%BiOBr composites degraded rhodamine B completely under visible light irradiation. The degradation ratio of brookite/g-C3N4/30%BiOBr toward rhodamine B was nearly 100% for 2[Formula: see text]h, which was much higher than that of brookite TiO2 and brookite/g-C3N4 catalysts. The reason for the improvement of photocatalytic activity might be because the composites promoted the formation of superoxide radicals and the separation efficiency of photogenerated electron-hole pairs. The photocurrent density of the brookite/g-C3N4/30%BiOBr was about 10 times higher than that of pure brookite. In addition, the brookite/g-C3N4/BiOBr showed a good repeatablity of photocatalysis.

scholarly journals Excellent Photocatalytic Rhodamine B Degradation for water Remediation Over Pr3+ Doped Bi2WO6 Microspheres

2021 ◽  
Author(s):  
Xianghui Zhang
Keyword(s):  
Rhodamine B ◽  
Organic Pollutant ◽  
Photogenerated Electron ◽  
Orthorhombic Phase ◽  
Water Remediation ◽  
Doping Amount ◽  
Electron Hole ◽  
Radical Trapping ◽  
One Step ◽  
Xrd Patterns

Abstract In this work, a serious of Pr3+ doped Bi2WO6 had been prepared by one-step hydrothermal method without using any additive. XRD results showed that the Pr3+ doped Bi2WO6 possessed pure orthorhombic phase. XRD patterns shifted to higher angles with the doping amount of Pr3+ increasing indicated that Pr3+ was doped into the lattice of Bi2WO6. UV-vis DRS results revealed that the band gap was narrowed by Pr3+ doping. SEM and TEM images showed that the Pr3+ doped Bi2WO6 presented 3D flower-like microspheres constructed by many nanosheets. The photocatalytic activities of the as-prepared samples were evaluated by using rhodamine B (RhB) as the target organic pollutant. It was found that 1% Pr-Bi2WO6 exhibited excellent photocatalytic performance, as well as good stability and reusability. The improved photocatalytic activity can be ascribed to the optimum optical absorption activity, the larger specific surface area and the morphology of microspheres which resulted in the effective separation of the photogenerated electron hole pairs. In addition, the photocatalytic mechanism had been discussed according to the radical-trapping experiments.

scholarly journals Synthesis and characterization of Fe-TiO2@SiO2@Fe3O4 magnetic visible light photocatalyst for removal of Rhodamine B dye

2021 ◽  
Vol 10 (2) ◽  
pp. 78-83
Author(s):  
Tien Nguyen Thi Thuy ◽  
Do Tran Dang ◽  
Viet Nguyen Minh ◽  
Ngoc Ha Minh ◽  
Minh Dang Nhat ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Rhodamine B ◽  
Sol Gel ◽  
Photogenerated Electron ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Visible Light Photocatalyst ◽  
Magnetic Curve ◽  
Co Precipitation

In this research, the magnetic visible light photocatalyst of Fe-TiO2@SiO2@Fe3O4 was synthesised using co-precipitation, sol-gel and hydrothermal method. The as-obtained material’s properties were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), diffuse reflectance spectra (UV- Vis), magnetic curve (VSM) and photoluminescence (PL). The catalytic activity of the materials under visible light was investigated for degradation of Rhodamine B pigment  in water. The obtained results indicated that at the catalyst dose of 0.5 g/L, Fe-TiO2@SiO2@Fe3O4 with TiO2/SiO2@Fe3O4 (SF) ratio of 2:1 performed the highest efficiency of  99.3 % after 180 minutes under irritation. The enhanced photocatalytic performance of Rhodamine B under visible light could be ascribed to the reducing of band gap energy and decrease in the recombination rate of photogenerated electron/hole pairs. The catalytic activity after four times of recycling were 71,3 %.The material showed potential for further application in water treatment.

Synthesis and characterization of the ZnO/mpg-C3N4 heterojunction photocatalyst with enhanced visible light photoactivity

2014 ◽  
Vol 43 (34) ◽  
pp. 13105-13114 ◽  
Author(s):  
Daimei Chen ◽  
Kewei Wang ◽  
Tiezhen Ren ◽  
Hao Ding ◽  
Yongfa Zhu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photogenerated Electron ◽  
Synthesis And Characterization ◽  
Electron Hole ◽  
Activity Enhancement ◽  
High Separation

The photocatalytic activity enhancement of the ZnO/mpg-C3N4 is due to the high separation and easy transfer 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.

Graphene oxide–ZnO nanocomposite: an efficient visible light photocatalyst for degradation of rhodamine B

2021 ◽  
Author(s):  
Asim Ali Yaqoob ◽  
Nur Habibah binti Mohd Noor ◽  
Khalid Umar ◽  
Rohana Adnan ◽  
Mohamad Nasir Mohamad Ibrahim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Rhodamine B ◽  
Visible Light Photocatalyst
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