scholarly journals Prediction of a Stable Organic Metal-Free Porous Material as a Catalyst for Water-Splitting

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 836
Author(s):  
Hengshuai Li ◽  
Haiquan Hu ◽  
Chenglin Bai ◽  
Chunjiang Bao ◽  
Cailong Liu ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Tensile Force ◽  
Practical Significance ◽  
Organic Metal ◽  
Electron Hole ◽  
Metal Free ◽  
Photocatalytic Application ◽  
The Stability ◽  
Dynamics Simulations ◽  
Hole Recombination

It is of practical significance to find organic metal-free catalyst materials. We propose a new graphene-like carbon nitride structure, which was able to meet these requirements well. Its primitive cell consists of eight carbon atoms and six nitrogen atoms. Hence, we called this structure g–C8N6. The stability of the structure was verified by phonon spectroscopy and molecular dynamics simulations. Then its electronic structure was calculated, and its band edge position was compared with the redox potential of water. We analyzed its optical properties and electron–hole recombination rate. After the above analysis, it is predicted that it is a suitable photocatalyst material. To improve its photocatalytic performance, two methods were proposed: applied tensile force and multilayer stacking. Our research is instructive for the photocatalytic application of this kind of materials.

Synthesis and Photocatalytic Degradation Performance of g-C3N4/ CoAPO-5/rGO Ternary Composite

2018 ◽  
Vol 281 ◽  
pp. 848-853
Author(s):  
Ling Fang Qiu ◽  
Xiao Bin Qiu ◽  
Zhi Wei Zhou ◽  
Shu Wang Duo
Keyword(s):  
Visible Light ◽  
Carbon Nitride ◽  
Photocatalytic Performance ◽  
Doping Content ◽  
Electron Mediator ◽  
Electron Hole ◽  
Obvious Effect ◽  
Ternary Composite ◽  
Hole Recombination ◽  
Binary Composite

Graphitic carbon nitride is a promising photocatalyst for environmental purification, but the photocatalytic performance is limited significantly due to its narrow visible-light adsorption and high photo-reduced electron-hole recombination rate. This work developed a novel way to overcome the two defects and obtained obvious effect. CoAPO-5 was used to broaden visible-light adsorption range by conducting g-C3N4/CoAPO-5 binary composite. In further, rGO was integrated into the binary system to form novel ternary composite. rGO performs as a electron mediator, which can inhibit photo-reduced electron-hole recombination efficiently. The samples were characterized by XRD, SEM, PL, IR and DRS. The photocatalytic performances for degrading RhB (10mg/L) indicated that g-C3N4/CoAPO-5/rGO have much higher activity than g-C3N4/CoAPO-5 because of synergistic effect. When the doping content of rGO in g-C3N4/CoAPO-5 was 0.5%, the degradation efficiency was improved by 14%.

Dynamic charge transfer through Fermi level equilibration in the p-CuFe2O4/n-NiAl LDH interface towards photocatalytic application

2020 ◽  
Vol 10 (18) ◽  
pp. 6285-6298 ◽  
Author(s):  
Snehaprava Das ◽  
Sulagna Patnaik ◽  
Kulamani Parida
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Energy Level ◽  
Fermi Level ◽  
Vacuum Energy ◽  
Electron Hole ◽  
Photocatalytic Application ◽  
Dynamic Charge ◽  
Hole Recombination

The Ni Al LDH–CuFe2O4 p–n heterojunction, through vacuum energy level bending, inhibits electron hole recombination and enhances photocatalytic activity.

Temperature and Salinity Effects on Photocatalytic Performance of Cerium Doped Zinc Oxide

2020 ◽  
Vol 307 ◽  
pp. 223-228
Author(s):  
Wan Rafizah Wan Abdullah ◽  
Lee Chia Siang ◽  
Maishara Syazrinni Rooshde ◽  
Mohd Sabri Mohd Ghazali
Keyword(s):  
Photocatalytic Performance ◽  
Catalyst Surface ◽  
Uv Light ◽  
Operating Temperature ◽  
Chloride Ions ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Doped Zno ◽  
The Stability ◽  
Uv C

Cerium (Ce) doped ZnO is a promising material for advanced photocatalysis. It is useful for inducing the treatment of many organic pollutants in water. However, the stability of its performance under varying temperature and saline condition has never been not fully assessed. In this study, powder form photocatalyst comprising 99.0 mol% ZnO and 1 mol% CeO2 has been synthesized via modified citrate gelation technique and solid-state sintering at 1200 °C for 5 hours. The conversion of Ce doped ZnO from its precursors has been confirmed using XRD, SEM, and EDX techniques. The photocatalytic efficiency of the synthesized Ce doped ZnO under UV-C light (λ=265 nm) was determined. In the experiment, the operating temperature was varied between 25 to 40 °C, and the salinity of the treated solution was increased from 0 to 40 g/L NaCl. The findings revealed that the photocatalytic efficiency of Ce doped ZnO under UV light improved from 78.2% to 88.6% as the temperature increased from 25 to 40 °C. The performance of Ce doped ZnO decreased from 86.7% to 36.7% when the salinity increased from 0 g/L to 40 g/L. The elevation of temperature encouraged the photogeneration of electron-hole pairs on catalyst surface while the presence of chloride ions in treated medium caused scavenging of hydroxyl radicals or hole.

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 Synthesis of Heterostructure of ZnO@MOF-46(Zn) to Improve the Photocatalytic Performance in Methylene Blue Degradation

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1379
Author(s):  
Jiraporn Buasakun ◽  
Phakinee Srilaoong ◽  
Ramida Rattanakam ◽  
Tanwawan Duangthongyou
Keyword(s):  
Methylene Blue ◽  
Band Gap ◽  
Photocatalytic Performance ◽  
Degradation Process ◽  
Band Gap Energy ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Methylene Blue Degradation ◽  
Gap Energy ◽  
Hole Recombination

The heterostructure of ZnO and MOF-46(Zn) was synthesized to improve the photocatalytic performance of ZnO and prove the synergistic theory that presented the coexistence of ZnO and MOF-46(Zn), providing better efficiency than pure ZnO. The heterostructure material was synthesized by using prepared ZnO as a Zn2+ source, which was reacted with 2-aminoterephthalic acid (2-ATP) as a ligand to cover the surface of ZnO with MOF-46(Zn). The ZnO reactant materials were modified by pyrolysis of various morphologies of IRMOF-3 (Zn-MOF) prepared by using CTAB as a morphology controller. The octahedral ZnO obtained at 150 mg of CTAB shows better efficiency for photodegradation, with 85.79% within 3 h and a band gap energy of 3.11 eV. It acts as a starting material for synthesis of ZnO@MOF-46(Zn). The ZnO/MOF-46(Zn) composite was further used as a photocatalyst material in the dye (methylene blue: MB) degradation process, and the performance was compared with that of pure prepared ZnO. The results show that the photocatalytic efficiency with 61.20% in the MB degradation of the heterostructure is higher than that of pure ZnO within 60 min (90.09% within 180 min). The reason for this result may be that the coexistence of ZnO and MOF-46(Zn) can absorb a larger range of energy and reduce the possibility of the electron–hole recombination process.

scholarly journals A metal-free 3C-SiC/g-C3N4 composite with enhanced visible light photocatalytic activity

RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 40028-40033 ◽  
Author(s):  
Hao Xu ◽  
Zhixing Gan ◽  
Weiping Zhou ◽  
Zuoming Ding ◽  
Xiaowei Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Carbon Nitride ◽  
Photocatalytic Performance ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Visible Light Absorption ◽  
Metal Free ◽  
Visible Light Photocatalytic

Insufficient visible light absorption and fast recombination of the photogenerated electron–hole pairs have seriously hampered the photocatalytic performance of graphitic carbon nitride (g-C3N4) up to now.

Enhanced visible light photocatalytic activity of AgI/TiO2 composite fabricated by a grinding method

2019 ◽  
Vol 54 (3) ◽  
pp. 257-264
Author(s):  
Jin Xu ◽  
Dasheng Gao ◽  
Shuang Cui ◽  
Xiaohua Wang ◽  
Ningning Liu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
Photogenerated Electron ◽  
Active Species ◽  
Electron Hole ◽  
Grinding Method ◽  
The Stability ◽  
Visible Light Photocatalytic

Abstract Through a simple grinding method, AgI/TiO2 composites were successfully synthesized. The as-prepared AgI/TiO2 composites were used as photocatalysts for Rhodamine B (RhB) degradation under visible light irradiation and exhibited excellent photocatalytic performance. In the presence of composites, almost 100% RhB was decomposed after 60 min. The photocatalytic activity of AgI/TiO2-0.5 composite was optimal, which was 9.5 times higher than that of pristine TiO2, and 15.6 times higher than that of AgI. Moreover, experimental results revealed that the improved photocatalytic activity was not only ascribed to the loading AgI but also resulted from the method that enabled the exposure of more active sites in the composites. In addition, the intimate interfacial contact obtained by this method could also promote the efficient separation of photogenerated electron-hole pairs. Moreover, the possible photocatalytic active species and the stability of the photocatalyst were investigated in detail.

scholarly journals A Contemporary Assessment on Composite Titania onto Graphitic Carbon Nitride-Based Catalyst as Photocatalyst

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Azami M. S. ◽  
Jalil A. A ◽  
Hitam C. N. C. ◽  
Mamat C. R ◽  
Siang T. J. ◽  
...  
Keyword(s):  
Band Gap ◽  
Carbon Nitride ◽  
Wide Band ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Electron Hole ◽  
Electronic Band ◽  
Metal Free ◽  
Physical And Chemical ◽  
Hole Recombination

Titanium dioxide (TiO2) has drawn widespread interest by researchers as a precious semiconductor that is responsive towards photodegradation of various pollutants. This catalyst has its own limitations such as fast electron-hole recombination, wide band gap, and can only be utilised under ultraviolet (UV) region. In order to overcome these problems, the addition of a metal-free dopant is a common practice to prevent electron-hole recombination and enhance photodegradation under visible light. Among various types of metal-free catalysts, carbon nitride material has received much attention due to its numerous benefits such as good in terms of physical and chemical strength, as well as an attractive electronic band combined with a band gap (2.7 eV). This review summarised recent works in the development of titania incorporated with graphitic carbon nitride (g-C3N4) for enhanced photocatalytic activity.

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