scholarly journals Biochar Nanoparticles over TiO2 Nanotube Arrays: A Green Co-Catalyst to Boost the Photocatalytic Degradation of Organic Pollutants

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1048
Author(s):  
Marco Pinna ◽  
Gilberto Binda ◽  
Marco Altomare ◽  
Marcello Marelli ◽  
Carlo Dossi ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Water Solution ◽  
Low Cost ◽  
Organic Pollutant ◽  
Tio2 Nanotube ◽  
Raw Material ◽  
Co Catalysts ◽  
Low Temperature Pyrolysis

Biochar nanoparticles (BC NPs), produced by low temperature pyrolysis (350 °C) of microalgae (Nannochloropsis sp.) and nutshells, are proposed as low-cost and sustainable co-catalysts to promote the photocatalytic activity of TiO2 nanotube (NT) arrays towards the degradation of methylene blue (MB) used as an organic pollutant model molecule. BC NPs (size < 25 nm) were obtained by treating bulk BC (i.e., biomass after pyrolysis) by sonication–centrifugation cycles in a water solution. The filtered BC NPs dispersion was deposited by simple drop-casting on the TiO2 NT support. The BC loading was varied by performing multiple depositions. Photocatalytic experiments under UV light (365 nm) revealed that the decoration with BC NPs significantly improves the TiO2 photoactivity. Such enhancement is mainly influenced by the amount of BC deposited; upon optimizing the BC deposition conditions, the rate of photocatalytic degradation of MB increases approximately three times with respect to bare TiO2, almost irrespective of the nature of the raw material. The greater photocatalytic activity of BC-TiO2 can be attributed to the synergistic combination of reactant/product adsorption and catalytic degradation of the adsorbed organic pollutant, as well as an improved charge carrier separation and electron transfer.

scholarly journals Innovative Low-Cost Carbon/ZnO Hybrid Materials with Enhanced Photocatalytic Activity towards Organic Pollutant Dyes’ Removal

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1873
Author(s):  
Petronela Pascariu ◽  
Niculae Olaru ◽  
Aurelian Rotaru ◽  
Anton Airinei
Keyword(s):  
Photocatalytic Activity ◽  
Hybrid Materials ◽  
Raw Materials ◽  
Structural Characteristics ◽  
Low Cost ◽  
Organic Pollutant ◽  
Zno Nanostructures ◽  
Zno Nanocrystals ◽  
Electrospinning Method ◽  
New Type

A new type of material based on carbon/ZnO nanostructures that possesses both adsorption and photocatalytic properties was obtained in three stages: cellulose acetate butyrate (CAB) microfiber mats prepared by the electrospinning method, ZnO nanostructures growth by dipping and hydrothermal methods, and finally thermal calcination at 600 °C in N2 for 30 min. X-ray diffraction (XRD) confirmed the structural characteristics. It was found that ZnO possesses a hexagonal wurtzite crystalline structure. The ZnO nanocrystals with star-like and nanorod shapes were evidenced by scanning electron microscopy (SEM) measurements. A significant decrease in Eg value was found for carbon/ZnO hybrid materials (2.51 eV) as compared to ZnO nanostructures (3.21 eV). The photocatalytic activity was evaluated by studying the degradation of three dyes, Methylene Blue (MB), Rhodamine B (RhB) and Congo Red (CR) under visible-light irradiation. Therefore, the maximum color removal efficiency (both adsorption and photocatalytic processes) was: 97.97% of MB (C0 = 10 mg/L), 98.34% of RhB (C0 = 5 mg/L), and 91.93% of CR (C0 = 10 mg/L). Moreover, the value of the rate constant (k) was found to be 0.29 × 10−2 min−1. The novelty of this study relies on obtaining new photocatalysts based on carbon/ZnO using cheap and accessible raw materials, and low-cost preparation techniques.

Hierarchical Z-scheme 1D/2D architecture with TiO2 nanowires decorated by MnO2 nanosheets for efficient adsorption and full spectrum photocatalytic degradation of organic pollutants

2020 ◽  
Vol 10 (11) ◽  
pp. 3603-3612
Author(s):  
Jiejing Zhang ◽  
Yajie Hu ◽  
Hong Zheng ◽  
Pengyi Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Organic Pollutant ◽  
Pollutant Removal ◽  
Tio2 Nanowires ◽  
Full Spectrum ◽  
Mno2 Nanosheets ◽  
Excellent Stability

A novel hierarchical 1D/2D TiO2/MnO2 composite shows superior adsorption, full spectrum photocatalytic activity and excellent stability for organic pollutant removal.

scholarly journals Preparation of ternary ZnO/Ag/cellulose and its enhanced photocatalytic degradation property on phenol and benzene in VOCs

2019 ◽  
Vol 17 (1) ◽  
pp. 779-787 ◽  
Author(s):  
Xiao-Hang Zou ◽  
Si-Wei Zhao ◽  
Ji-Guo Zhang ◽  
Hui-Liang Sun ◽  
Qing-Jiang Pan ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Separation Efficiency ◽  
Uv Light ◽  
Low Cost ◽  
Visible Region ◽  
X Ray Diffraction ◽  
Ternary Composite ◽  
Photogenerated Electrons ◽  
Excellent Photocatalytic Activity ◽  
Diffraction Patterns

AbstractThe ZnO/Ag/cellulose composite (ZAC) with excellent photocatalytic activity of degrading benzene and phenol in VOCs has been successfully synthesized. EDS, TEM, XPS and UV-vis analyses show that the ZAC is a ternary composite. It is composed of Ag, ZnO and cellulose, where the cellulose works as the substrate to anchor the other two components. The X-ray diffraction patterns find well-crystallized ZnO nanoparticles. Multiple PL peaks in the visible region measured for ZAC, imply rich defects on ZnO. It is observed that Ag nanoparticles are mainly attached on ZnO in the composite, which would raise the separation efficiency of photogenerated electrons and holes. Photocatalytic degradation shows that ZAC is able to decompose almost 100% phenol and 19% benzene in VOCs under UV light irradiation (6 W) which is almost no harm to human body. Due to the renewable cellulose, our ternary composite ZAC imparts low-cost, easily recycled and flexible merits, which might be applied in the indoor VOCs treatment.

Magnetic field assisted photocatalytic degradation of organic dyes in the presence of Ag/TiO2 coated composite

2013 ◽  
Vol 67 (4) ◽  
pp. 722-728 ◽  
Author(s):  
Jian Wang ◽  
Jingqun Gao ◽  
Jun Wang ◽  
Yu Zhai ◽  
Zhongxing Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Rotational Speed ◽  
Organic Dyes ◽  
Dye Degradation ◽  
Uv Light ◽  
Irradiation Time ◽  
Sol Gel ◽  
Heat Treated

Ag/TiO2 coated composite was prepared via sol-gel method in order to elucidate its application in magnetic field assisted photocatalytic degradation of dyes. Through the degradation of organic dyes, the key influences such as Ag amount, heat-treated temperature and time on the photocatalytic activity of Ag/TiO2, as well as UV irradiation time, rotational speed, dye concentration and magnetic sheet number on the photocatalytic degradation were studied. Results showed that the Ag/TiO2 with 25 wt% Ag content heat-treated at 550 °C for 60 min has the best photocatalytic activity. With the increase of UV light irradiation time, rotational speed and magnetic sheet number, the degradation rate is improved. Different dye degradation proved that the method could universally be used.

scholarly journals Cobalt Oxide-Modified Titanium Dioxide Nanoparticle Photocatalyst for Degradation of 2,4-Dichlorophenoxyacetic Acid

2017 ◽  
Vol 17 (2) ◽  
pp. 284 ◽  
Author(s):  
Leny Yuliati ◽  
Nur Azmina Roslan ◽  
Wai Ruu Siah ◽  
Hendrik Oktendy Lintang
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Cobalt Oxide ◽  
Uv Light ◽  
Dichlorophenoxyacetic Acid ◽  
Photocatalytic Reaction ◽  
Impregnation Method ◽  
Titanium Dioxide Nanoparticle ◽  
2,4 Dichlorophenoxyacetic Acid

2,4-dichlorophenoxyacetic acid (2,4-D) has been recognized as a possibly carcinogenic compound to human, therefore, 2,4-D should be treated before it is discharged to the environment. Photocatalytic degradation of 2,4-D has been proposed as one of the best methods that offer environmentally safe process. In the present research, titanium dioxide (TiO2) was modified with cobalt oxide (CoO) and tested for photocatalytic degradation of 2,4-D under UV light irradiation. Different amounts of CoO (0.1, 0.5, 1 and 5 mol%) were added onto TiO2 by an impregnation method. The photocatalytic reaction was monitored and analyzed by measurement of 2,4-D absorbance using UV spectrophotometer. After 1 h photocatalytic reaction, it was confirmed that the sample with low loading of 0.1 mol% gave the highest photocatalytic activity among the bare and modified TiO2 photocatalysts. The photocatalytic activity was decreased with the increase of CoO loading, suggesting that the optimum amount of CoO was an important factor to improve the performance of TiO2. Based on fluorescence spectroscopy, such addition of CoO resulted in the reduced emission intensity, which showed the successful decrease in the electron-hole recombination.

scholarly journals Preparation and Photocatalytic Activity of TiO2/Fine Char for Removal of Rhodamine B

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mingjie Ma ◽  
Weijie Guo ◽  
Zhengpeng Yang ◽  
Shanxiu Huang ◽  
Guanyu Wang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Uv Light ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Light Irradiation

TiO2/fine char (FC) photocatalyst was prepared via sol-gel method with tetrabutyl titanate as the precursor and FC as the carrier. The structural property of TiO2/FC photocatalyst was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the photocatalytic activity of TiO2/FC was evaluated by photocatalytic degradation of rhodamine B (RhB) aqueous solution under UV light irradiation. The results showed that TiO2was successfully coated on the surface of FC, and the TiO2/FC photocatalyst had better photocatalytic efficiency and stability for degradation of RhB under UV light illumination as compared to that of the pure TiO2and FC. The study provided a novel way for the application of FC to the photocatalytic degradation of organic wastes.

Fabrication and characterization of CdS doped TiO2 nanotube composite and its photocatalytic activity for the degradation of methyl orange

2015 ◽  
Vol 72 (8) ◽  
pp. 1341-1347
Author(s):  
Jinwook Chung ◽  
Seu-Run Kim ◽  
Jong-Oh Kim
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Uv Light ◽  
Pure Tio2 ◽  
Tio2 Nanotube ◽  
Doped Tio2 ◽  
Photodegradation Efficiency ◽  
Uv Light Irradiation ◽  
Fabrication And Characterization

CdS doped TiO2 nanotube composite was fabricated by chemical bath deposition, and was characterized by the structural, spectral and photoelectrochemical properties. The results of the structural and spectral properties showed that CdS particles were successfully deposited onto the surface of TiO2 nanotube. It is demonstrated that CdS doped TiO2 nanotube composite improved the light harvesting ability. Power conversion efficiency of about 0.32% was observed. This value is about 2.9 times higher than that of pure TiO2 nanotube. The CdS doped TiO2 nanotube composite possesses relatively higher photocatalytic activity and photodegradation efficiency than that of pure TiO2 nanotube under UV light irradiation, and the degradation efficiency of methyl orange was about 42% at UV intensity of 32 W.

Synthesis of Composite TiO2/Natural Cotton Cellulose Nanofiber with Photocatalytic Property

2014 ◽  
Vol 665 ◽  
pp. 393-396
Author(s):  
Qiu Yan Liu ◽  
Jing Li ◽  
Jun Cao ◽  
Chao Rong Li
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Organic Pollutant ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Important Application ◽  
Anatase Structure ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Hydrothermal Methods

TiO2/NCCN nanocomposites have been prepared by sol-gel and hydrothermal methods. Firstly, the NCCN was prepared by electrospinning technology, then the amorphous TiO2films were coated on the surface of the NCCN by a sol-gel method, and TiO2(anatase structure) nanoparticles could be fixed on the surface of NCCN by a hydrothermal method to get higher photocatalysis efficiency. The photocatalytic activities indicate that the TiO2/NCCN nanocomposites exhibited a good photocatalytic activity for photodegradation of methylthionine chloride (MO) solution under UV light irradiation, leading to an important application in photodegradation of organic pollutant.

scholarly journals Microwave-assisted synthesis of photoluminescent carbon dots from palm fronds biomass wastes

2021 ◽  
Vol 1195 (1) ◽  
pp. 012008
Author(s):  
W L Ang ◽  
Q A Alqasem ◽  
A W Mohammad
Keyword(s):  
Microwave Irradiation ◽  
Carbon Dots ◽  
Uv Light ◽  
Water Solution ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
Photoluminescence Intensity ◽  
Irradiation Power ◽  
Higher Temperature ◽  
Palm Fronds

Abstract Oil palm fronds (OPF) is one of the largest biomass sources in Malaysia that has been underutilized. In this work, OPF has been used as a precursor to synthesize carbon dots (CDs) via microwave irradiation method. The impacts of irradiation power and duration and the reacting solution have been investigated. It was discovered that CDs with the highest photoluminescence intensity was obtained at microwave irradiation power of 385 W for 30 s. Irradiation at lower or higher power resulted in incomplete or over carbonization that reduced the fluorescence property. In addition, CDs synthesized with diethylene glycol (DEG) as reacting solution possessed higher photoluminescence intensity as compared to ultrapure water solution. This could be attributed to more complete CDs formation that happened at higher temperature, which could only be achieved by DEG solution (higher boiling point). The CDs were then tested as a sensor for lead (II) ions. The UV-vis absorbance was found to be reduced with the presence of lead (II) ions. This indicated that the lead (II) ions might interact with CDs and disrupted with the absorbance of UV light. Overall, OPF could be a potential precursor for the synthesis of low-cost and easily available CDs for environmental applications.

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