scholarly journals A High-Efficiency TiO2/ZnO Nano-Film with Surface Oxygen Vacancies for Dye Degradation

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3299
Author(s):  
Huizhong Ma ◽  
Baofei Hao ◽  
Wentao Song ◽  
Jinpeng Guo ◽  
Mingyuan Li ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
High Efficiency ◽  
Dye Degradation ◽  
Charge Carriers ◽  
Surface Oxygen ◽  
Electron Hole ◽  
Surface Separation ◽  
Green Approach ◽  
Compositional Properties

Photocatalytic degradation of organic pollutants in water is a highly efficient and green approach. However, the low quantum efficiency is an intractable obstacle to lower the photocatalytic efficiency of photocatalysts. Herein, the TiO2/ZnO heterojunction thin films combined with surface oxygen vacancies (OVs) were prepared through magnetron sputtering, which was designed to drive rapid bulk and surface separation of charge carriers. The morphology and structural and compositional properties of films were investigated via different techniques such as SEM, XRD, XPS, Raman, AFM, and XPS. It has been found that by controlling the O2/Ar ratio, the surface morphology, thickness, chemical composition, and crystal structure can be regulated, ultimately enhancing the photocatalytic performance of the TiO2/ZnO heterostructures. In addition, the heterojunction thin film showed improved photocatalytic properties compared with the other nano-films when the outer TiO2 layer was prepared at an O2/Ar ratio of 10:35. It degraded 88.0% of Rhodamine B (RhB) in 90 min and 90.8% of RhB in 120 min. This was attributed to the heterojunction interface and surface OVs, which accelerated the separation of electron–hole (e–h) pairs.

scholarly journals Enhanced Visible-Light Photocatalytic Performance of SAPO-5-Based g-C3N4 Composite for Rhodamine B (RhB) Degradation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Redox Reactions ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Thermal Polymerization ◽  
Light Illumination ◽  
Electron Hole ◽  
Visible Light Illumination ◽  
Visible Light Photocatalytic

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.

scholarly journals Ag as Cocatalyst and Electron-Hole Medium in CeO2 QDs/Ag/Ag2Se Z-scheme Heterojunction Enhanced the Photo-Electrocatalytic Properties of the Photoelectrode

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 253 ◽  
Author(s):  
Lingwei Li ◽  
Hange Feng ◽  
Xiaofan Wei ◽  
Kun Jiang ◽  
Shaolin Xue ◽  
...  
Keyword(s):  
High Speed ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Interfacial Region ◽  
Photogenerated Carrier ◽  
Electron Hole ◽  
Carrier Recombination ◽  
Photocatalytic System ◽  
Nano Channel ◽  
Active Substances

A recyclable photoelectrode with high degradation capability for organic pollutants is crucial for environmental protection and, in this work, a novel CeO2 quantum dot (QDs)/Ag2Se Z-scheme photoelectrode boasting increased visible light absorption and fast separation and transfer of photo-induced carriers is prepared and demonstrated. A higher voltage increases the photocurrent and 95.8% of tetracycline (TC) is degraded by 10% CeO2 QDs/Ag2Se in 75 minutes. The degradation rate is superior to that achieved by photocatalysis (92.3% of TC in 90 min) or electrocatalysis (27.7% of TC in 90 min). Oxygen vacancies on the CeO2 QDs advance the separation and transfer of photogenerated carriers at the interfacial region. Free radical capture tests demonstrate that •O2−, •OH, and h+ are the principal active substances and, by also considering the bandgaps of CeO2 QDs and Ag2Se, the photocatalytic mechanism of CeO2 QDs/Ag2Se abides by the Z-scheme rather than the traditional heterojunction scheme. A small amount of metallic Ag formed in the photocatalysis process can form a high-speed charge transfer nano channel, which can greatly inhibit the photogenerated carrier recombination, improve the photocatalytic performance, and help form a steady Z-scheme photocatalysis system. This study would lay a foundation for the design of a Z-scheme solar photocatalytic system.

Perylene Tetracarboxylic Tetraester Sensitized Titanium Dioxide Nanocomposite for Enhanced Photodegradation

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050100
Author(s):  
Fengxia Zhang ◽  
Haining Liu ◽  
Tianyi Jiang ◽  
Yanyan Zhu ◽  
Xiushen Ye ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Dye Degradation ◽  
Butyl Ester ◽  
Charge Carriers ◽  
Photoluminescence Intensity ◽  
Radical Scavengers ◽  
Electron Hole ◽  
Ft Ir ◽  
Hole Recombination ◽  
Active Substances

The construction of organic–inorganic hybrids is one of the important ways to improve performances of photocatalysts. In this study, perylene tetracarboxylic tetra (n-butyl) ester loaded titanium dioxide (PTTE-B/TiO2) nanocomposite was successfully synthesized by hydrothermal method. The catalyst was characterized by XRD, DRS, XPS, Photoluminescence spectroscopy (PL) and BET. FT-IR and XPS analyses revealed the presence of Ti[Formula: see text]O bond in the interfaces between TiO2 and PTTE-B. The photoluminescence intensity of PTTE-B/TiO2 was decreased compared to TiO2, which indicated a suppression of electron–hole recombination by the loaded PTTE-B nanoparticles. The photocatalytic activity of PTTE-B/TiO2 nanocomposite for degradation of EBT using visible light was higher than that of prepared TiO2 or TiO2-P25. The detection of radical scavengers confirmed that h[Formula: see text] and [Formula: see text] were the main active substances for Eriochrome Black T (EBT, an azo dye) degradation. The Ti[Formula: see text]O bond acted as a short and fast channel for photogenerated charge carriers to migrate from PTTE-B to TiO2. Furthermore, PTTE-B/TiO2 was found to be stable and reusable.

Hierarchical WO3 microflowers with tailored oxygen vacancies for boosting photocatalytic dye degradation

2021 ◽  
Author(s):  
Jianqiang Qiu ◽  
Fengxia Xu ◽  
Bei Jin ◽  
Yangang Sun ◽  
Jinguo Wang
Keyword(s):  
Visible Light ◽  
Oxygen Vacancies ◽  
Dye Degradation ◽  
Surface Oxygen ◽  
Visible Light Driven ◽  
Photocatalytic Dye Degradation

Hierarchical WO3 microflowers with tailored surface oxygen vacancies show a remarkably boosted activity toward visible-light-driven photocatalytic dye degradation.

Surface oxygen vacancy and defect engineering of WO3 for improved visible light photocatalytic performance

2018 ◽  
Vol 8 (17) ◽  
pp. 4399-4406 ◽  
Author(s):  
Qi Liu ◽  
Fengjiao Wang ◽  
Huaxiang Lin ◽  
Yanyu Xie ◽  
Na Tong ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Photogenerated Electron ◽  
Vacancy Defect ◽  
Surface Oxygen ◽  
Defect Engineering ◽  
Electron Hole ◽  
Surface Oxygen Vacancy ◽  
Visible Light Photocatalytic

Compared to the pristine WO3, the oxygen vacancy defect levels of the sub-stoichiometric WO3−X narrow the bandgap and promote the separation of photogenerated electron–hole pairs.

Relationships of surface oxygen vacancies with photoluminescence and photocatalytic performance of ZnO nanoparticles

2005 ◽  
Vol 48 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Liqiang Jing ◽  
Fulong Yuan ◽  
Haige Hou ◽  
Baifu Xin ◽  
Weimin Cai ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Surface Oxygen
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