scholarly journals Synthesis, Characterization, and Photocatalytic Activity of N-Doped ZnO/ZnS Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Hongchao Ma ◽  
Xiaohong Cheng ◽  
Chun Ma ◽  
Xiaoli Dong ◽  
Xinxin Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Treatment Approach ◽  
Absorption Efficiency ◽  
Electron Hole ◽  
Anthraquinone Dye ◽  
N Doping ◽  
Doped Zno ◽  
Zno Semiconductor ◽  
High Absorption

The aim of the present study is to enhance photocatalytic performance of ZnO semiconductor by comodification with doping of nonmetal ions and coupling with another semiconductor. Therefore, we synthesized the N-doped ZnO/ZnS photocatalysts via a simple heat-treatment approach using L-cysteine as N and S source in this work. Anthraquinone dye (reactive brilliant blue KNR) is employed as the model contaminants to evaluate the photocatalytic activity of as-synthesized samples under sunlight illumination. The N-doped ZnO/ZnS synthesized by this method shows better photocatalytic activity as compared to that of pure ZnO. The enhanced photocatalytic activity of the N-doped ZnO/ZnS composites may be related to the existence of N doping, ZnS/ZnO heterostructure, and covered abundant carbon species on the photocatalyst surface, which causing high absorption efficiency of light, efficient separation of electron-hole pairs, and quick surface reaction in doped ZnO.

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.

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 Photoelectrochemical and theoretical investigation of the photocatalytic activity of TiO2 : N

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89687-89698 ◽  
Author(s):  
Gabriela Byzynski Soares ◽  
Renan Augusto Pontes Ribeiro ◽  
Sergio Ricardo de Lazaro ◽  
Caue Ribeiro
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Effective Mass ◽  
Theoretical Investigation ◽  
Hole Pair ◽  
Electron Hole ◽  
Electron Hole Pair ◽  
N Doping ◽  
Hole Recombination

In N-doping on TiO2 nanomaterial occurs a big decrease of band-gap (1 eV); however, its photocatalysis is low. We clarify such fact from effective mass, i.e., the electron–hole recombination is more than creation of electron–hole pair.

The nanocomposite of polyaniline and nitrogen-doped layered HTiNbO5with excellent visible-light photocatalytic performance

2014 ◽  
Vol 16 (26) ◽  
pp. 13409-13417 ◽  
Author(s):  
Chao Liu ◽  
Liang Wu ◽  
Jing Chen ◽  
Ji-yuan Liang ◽  
Chang-shun Li ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Charge Separation ◽  
Photocatalytic Performance ◽  
High Efficiency ◽  
Nitrogen Doped ◽  
Visible Light Photocatalytic Activity ◽  
N Doping ◽  
Visible Light Photocatalytic

N-doping and intercalation resulted in a PANI–N-HTiNbO5lamellar nanocomposite, which showed a dramatic enhanced visible-light photocatalytic activity and stability for the degradation of methylene blue (MB), due to the high efficiency of charge separation.

scholarly journals Preparation and Photocatalytic Properties of Metal-Doped ZnO Nanofilms Grown on Graphene-Coated Flexible Substrates

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3589
Author(s):  
Ping Rong ◽  
Shuai Ren ◽  
Jianchao Jiang ◽  
Qi Yu ◽  
Liyun Jiang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Flexible Substrate ◽  
Flexible Substrates ◽  
Uv Light Irradiation ◽  
Structure Morphology ◽  
Metal Element ◽  
Doped Zno ◽  
Metal Doped

A series of metal element (Al, Fe, Mg and Ni)-doped ZnO (M-ZnO) photocatalysts have been successfully synthesized on graphene-coated polyethylene terephthalate (GPET) flexible substrate via the hydrothermal method. The effects of doped metals in ZnO were also studied on the crystal structure, morphology and photocatalytic performance. The photocatalytic experiment results indicated that, compared with Al-, Mg- and Fe-ZnO/GPET photocatalysts under ultraviolet (UV) light irradiation, Ni-ZnO/GPET had better photocatalytic activity, and the degradation rate of methylene blue (MB) was 81.17%. Meanwhile, the mechanism of enhancing the photocatalytic activity of metal element-doped ZnO is also discussed. It is concluded that, after doping with metal elements, electrons and holes are prevented from recombination by trapping electrons of the ZnO/GPET conductive band, thereby improving the photocatalytic activity.

scholarly journals Growth Process and CQDs-modified Bi4Ti3O12 Square Plates with Enhanced Photocatalytic Performance

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 66 ◽  
Author(s):  
Xinxin Zhao ◽  
Hua Yang ◽  
Ziming Cui ◽  
Xiangxian Wang ◽  
Zao Yi
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Growth Process ◽  
Photocatalytic Performance ◽  
Simulated Sunlight ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
X Ray ◽  
Photocurrent Spectroscopy

Bi4Ti3O12 square plates were synthesized via a hydrothermal route, and their growth process was systematically investigated. Carbon quantum dots (CQDs) were prepared using glucose as the carbon source, which were then assembled on the surface of Bi4Ti3O12 square plates via a hydrothermal route with the aim of enhancing the photocatalytic performance. XRD (X-ray powder diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), UV-vis DRS (diffuse reflectance spectroscopy), XPS (X-ray photoelectron spectroscopy), FTIR (Fourier transform infrared spectroscopy), PL (photoluminescence) spectroscopy, EIS (electrochemical impedance spectroscopy) and photocurrent spectroscopy were used to systematically characterize the as-prepared samples. It is demonstrated that the decoration of CQDs on Bi4Ti3O12 plates leads to an increased visible light absorption, slightly increased bandgap, increased photocurrent density, decreased charge-transfer resistance, and decreased PL intensity. Simulated sunlight and visible light were separately used as a light source to evaluate the photocatalytic activity of the samples toward the degradation of RhB in aqueous solution. Under both simulated sunlight and visible light irradiation, CQDs@Bi4Ti3O12 composites with an appropriate amount of CQDs exhibit obviously enhanced photocatalytic performance. However, the decoration of excessive CQDs gives rise to a decrease in the photocatalytic activity. The enhanced photocatalytic activity of CQDs-modified Bi4Ti3O12 can be attributed to the following reasons: (1) The electron transfer between Bi4Ti3O12 and CQDs promotes an efficient separation of photogenerated electron/hole pairs in Bi4Ti3O12; (2) the up-conversion photoluminescence emitted from CQDs could induce the generation of additional electron/hole pairs in Bi4Ti3O12; and (3) the photoexcited electrons in CQDs could participate in the photocatalytic reactions.

In situ bubble template promoted facile preparation of porous g-C3N4 with excellent visible-light photocatalytic performance

RSC Advances ◽  
2015 ◽  
Vol 5 (78) ◽  
pp. 63264-63270 ◽  
Author(s):  
Lei Shi ◽  
Lin Liang ◽  
Fangxiao Wang ◽  
Mengshuai Liu ◽  
Tao Liang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Recombination Rate ◽  
Photocatalytic Performance ◽  
Electron Hole ◽  
Facile Preparation ◽  
Bubble Template ◽  
Splitting Water ◽  
Visible Light Photocatalytic

pg-C3N4 prepared through in situ bubble template showed large surface area and low recombination rate of photoinduced electron–hole pairs, leading to enhanced visible-light photocatalytic activity for degrading pollutants and splitting water to H2.

Hydrothermal Preparation, Characterization and Photocatalytic Properties of C, N Co-Doped ZnO/ZnS Composites

2012 ◽  
Vol 610-613 ◽  
pp. 1841-1844
Author(s):  
Ying Huan Fu ◽  
Ke Teng ◽  
Xiao Li Dong ◽  
Chun Ling Yu ◽  
Chun Ma ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Performance ◽  
Raw Materials ◽  
Hydrothermal Process ◽  
Solar Irradiation ◽  
Hydrothermal Preparation ◽  
Electron Hole ◽  
Electron Hole Pair ◽  
Doped Zno ◽  
Co Doped

C, N, S co-doped ZnO/ZnS composites were prepared by hydrothermal method using ZnSO4 and L-cysteine as raw materials, and investigated by UV-vis DRS, XRD, XPS. The results showed that C, N, S have successfully doped onto ZnO and substituted O of crystal lattice during hydrothermal process. The resulting co-doped ZnO composites exhibit significantly higher photocatalytic activity (45%) than that of pure ZnO (<5%) for degradation of reactive brilliant blue KN-R aqueous solution under simulative solar irradiation. The enhancement of photocatalytic performance of co-doped composites can be attributed to the reducing of electron-hole pair recombination and narrowed band gap.

scholarly journals Phthalocyanine-sensitized hollow ZnO spheres as an efficient visiblie-light photocatalyst for water treatment

2020 ◽  
Vol 194 ◽  
pp. 04057
Author(s):  
Cong Liu ◽  
Qian Duan
Keyword(s):  
Photocatalytic Activity ◽  
Water Treatment ◽  
Visible Light ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Solvothermal Method ◽  
Electron Hole ◽  
Hierarchical Nanostructure ◽  
Facile Solvothermal Method

A novel phthalocyanine-sensitized hollow ZnO spheres as an efficient visiblie-light photocatalyst had been prepared successfully. Firstly, a unique hollow ZnO microsphere had been prepared by a facile solvothermal method followed by calcination. Secondly, zinc-tetracarboxyl-phthalocyanine (Pc) impregnated onto the surface of hollow ZnO microsphere. The obtained photocatalyst Pc/ZnO was characterized by XRD, SEM and EDS. The hollow Pc/ZnO hierarchical nanostructure improved the electron-hole separation more effectively and Pc loaded on the surface of ZnO microsphere to enhance photocatalytic activity under visible light. In our photocatalytic experiments, the hollow Pc/ZnO microsphere showed excellent photocatalytic performance under visible light for the removal of Rhodamine B (RhB). As a result, our work provided an effective and green photocatalyst for water treatment.

Enhanced Photocatalytic Performance of Oriented ZnWO4 Nanorods via Graphene Hybridization

2014 ◽  
Vol 602-603 ◽  
pp. 970-974
Author(s):  
Feng Zhou ◽  
Su Zhan
Keyword(s):  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Electron Hole ◽  
Enhancement Mechanism

The hybridization of graphene with oriented ZnWO4photocatalysts effectively enhanced the photocatalytic activity. The enhancement in photocatalytic performance was relied on the amount of graphene and the optimal hybridized amount of graphene was about 2 wt%. The photocatalytic activity was increased by about 3 times after ZnWO4was hybridized with graphene under UV irradiation. The enhancement mechanism of the photocatalytic activity is attributed to the higher separation efficiency and the inhibition of recombination of photoinduced electron-hole pairs.

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