scholarly journals Synthesis and Characterization of Manganese-Modified Black TiO2 Nanoparticles and Their Performance Evaluation for the Photodegradation of Phenolic Compounds from Wastewater

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7422
Author(s):  
Muhammad Irfan ◽  
Rab Nawaz ◽  
Javed Akbar Khan ◽  
Habib Ullah ◽  
Tahir Haneef ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Total Phenolic ◽  
Defect States ◽  
Recombination Suppression ◽  
Tio2 Nps ◽  
Mn Doping ◽  
Photodegradation Efficiency ◽  
Black Tio2

The release of phenolic-contaminated treated palm oil mill effluent (TPOME) poses a severe threat to human and environmental health. In this work, manganese-modified black TiO2 (Mn-B-TiO2) was produced for the photodegradation of high concentrations of total phenolic compounds from TPOME. A modified glycerol-assisted technique was used to synthesize visible-light-sensitive black TiO2 nanoparticles (NPs), which were then calcined at 300 °C for 60 min for conversion to anatase crystalline phase. The black TiO2 was further modified with manganese by utilizing a wet impregnation technique. Visible light absorption, charge carrier separation, and electron–hole pair recombination suppression were all improved when the band structure of TiO2 was tuned by producing Ti3+ defect states. As a result of the enhanced optical and electrical characteristics of black TiO2 NPs, phenolic compounds were removed from TPOME at a rate of 48.17%, which is 2.6 times higher than P25 (18%). When Mn was added to black TiO2 NPs, the Ti ion in the TiO2 lattice was replaced by Mn, causing a large redshift of the optical absorption edges and enhanced photodegradation of phenolic compounds from TPOME. The photodegradation efficiency of phenolic compounds by Mn-B-TiO2 improved to 60.12% from 48.17% at 0.3 wt% Mn doping concentration. The removal efficiency of phenolic compounds from TPOME diminished when Mn doping exceeded the optimum threshold (0.3 wt%). According to the findings, Mn-modified black TiO2 NPs are the most effective, as they combine the advantages of both black TiO2 and Mn doping.

Effects the Surface of Solar-light Photocatalytic Activity of Ag-doped TiO2 Nanohybrid Material prepared with a Novel Approach

2021 ◽  
Author(s):  
G. Nagaraj ◽  
Mustafa K. A. Mohammed ◽  
Haider G. Abdulzahraa ◽  
S. Tamilarasu
Keyword(s):  
Visible Light ◽  
Degradation Rate ◽  
Titanium Dioxide Nanoparticles ◽  
Resonance Phenomenon ◽  
Bandgap Energy ◽  
Effective Strategy ◽  
Tio2 Nps ◽  
Photodegradation Efficiency ◽  
Novel Approach ◽  
Nanohybrid Material

Abstract Surface modification with a nanomaterial has been confirmed to be an effective strategy to enhance the visible-light photodegradation efficiency of titanium dioxide nanoparticles (TiO2-NPs). In this regard, we used silver as an additive into TiO2-NPs to improve their photodegradation activity under visible light irradiation. Herein, a novel and eco-friendly process was developed to prepare the Ag-doped TiO2 nanohybrid and named as photon-induced method (PIM). The XRD technique showed that the prepared Ag-doped TiO2 has mixed phases of anatase and rutile. However, the rutile-only phase was detected for the pure TiO2-NPs at 700°C of calcination. Ultraviolet-visible (UV-vis) absorption spectra revealed a reduction in the bandgap energy of TiO2 after Ag doping. Besides, the addition of Ag resulted in a significant improvement of TiO2 morphology. Methlyene blue (MB) dye was chosen to be an organic target to investigate the photocatalyst activity of the TiO2-NPs. In this regard, the degradation rate of MB was found to be 100% for the Ag-doped TiO2, which is higher than that of pure rutile TiO2. The incorporation of Ag additive plays a significant role in the improvement of TiO2 stability and photodegradation performance due to the surface plasmon resonance phenomenon.

scholarly journals Visible Light-Driven high Photocatalytic Activity of Cu-Doped TiO2 Nanoparticles Synthesized by Hydrothermal Method

2018 ◽  
Vol 15 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Ravi Kamble ◽  
Smita Mahajan ◽  
Vijaya Puri ◽  
Harish Shinde ◽  
Kalayanrao Garadkar
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Hydrothermal Method ◽  
Anatase Phase ◽  
Visible Region ◽  
Oxygen Demand ◽  
High Photocatalytic Activity ◽  
Tio2 Nps ◽  
Doped Tio2 ◽  
Tio2 Lattice

TiO2 and Cu-doped TiO2 nanoparticles (NPs) with totally extraordinary substance of Cu by exploitation hydrothermal method. The part immaculateness, morphology, molecule estimate, optical properties, and elemental composition of as-incorporated Cu-doped TiO2 NPs were investigated by numerous systematic methods. The XRD designs unveiled Cu-doped TiO2 NPs inside the part unadulterated anatase phase. The plane of (101) XRD and XPS results show the lucky doping of Cu2+ inside the TiO2 lattice. The optical edges of Cu-doped TiO2 demonstrated a transparent light absorption in visible region that assumes an essential part inside the photocatalytic action underneath characteristic daylight. Certain Cu2+ content shows least PL intensity that backings the decrease in recombination rate of charge species. In addition, to get a handle on photocatalytic action, we have tried Cu-doped TiO2 for the degradation of Malachite Green (MG) under visible light. A large portion of 85% degradation was found for Cu-doped TiO2 (1.71 wt.%) underneath daylight minimum of 180 min, severally, that is past that of TiO2 (53%). Also, the degradation of the MG was affirmed by measurement of the chemical oxygen demand of the photodegraded solution. These outcomes demonstrates that the Cu-doped TiO2 NPs are extremely productive for the photodegration of the MG.

scholarly journals One-Step Synthesis of Ag@TiO2 Nanoparticles for Enhanced Photocatalytic Performance

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1032 ◽  
Author(s):  
Yufan Zhang ◽  
Fan Fu ◽  
Yuzhou Li ◽  
Desuo Zhang ◽  
Yuyue Chen
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Uv Light ◽  
Silver Ions ◽  
Pure Tio2 ◽  
Light Irradiation ◽  
Ag Nps ◽  
Tio2 Nps ◽  
Experimental Process ◽  
One Step

Polyamide network polymers (PNP) modified TiO2 nanoparticles (NPs) were decorated with Ag NPs in hydrothermal gel method, forming one-step synthesized photocatalysts, Ag@TiO2 NPs. The effect of PNP and the amount of Ag NPs added were investigated in this work. PNP acted as a nanocage to prevent TiO2 aggregation and capture Ag accurately, which could effectively control product sizes and improve dispersibility in solvents. Simultaneously, TiO2 NPs modified with Ag NPs exhibited remarkable photocatalytic effects. One-step synthesis simplified the experimental process and avoided the agglomeration of silver ions during the secondary reaction, achieving the purpose of uniform distribution at a specific location of TiO2 NPs. The prepared Ag@TiO2 NPs-0.5 could remove 79.49% of Methyl Orange (MO) after 3 h of ultraviolet light irradiation, which was 2.7 times higher than the reaction rate of pure TiO2 NPs. It also exhibited good photoactivity under Visible light conditions. Moreover, the mineralization rate of MO over the Ag@TiO2 NPs-0.5 could be up to 72.32% under UV light and 47.08% under Visible light irradiation, which revealed that the prepared catalysts could effectively degrade most of the MO to CO2 and H2O. The samples also demonstrated the excellent stability and easy recyclability with over 90% of the original catalytic level for MO degradation. The photocatalysts studied also exerted broad application prospects such as photovoltaic hydrogen production, electronic sensors and biomedicine.

scholarly journals The Photocatalytic Degradation of Vehicle Exhausts by an Fe/N/Co–TiO2 Waterborne Coating under Visible Light

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3378 ◽  
Author(s):  
Huiyun Xia ◽  
Guanyu Liu ◽  
Rui Zhang ◽  
Lifang Song ◽  
Huaxin Chen
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Alkali Resistance ◽  
Vehicle Exhaust ◽  
Exposure Test ◽  
Pencil Hardness ◽  
Tio2 Nps ◽  
X Ray ◽  
Degradation Rates

Based on the three-dimensional network structure of a polymer and the principle of photocatalysts, a visible-light-responsive and durable photocatalytic coating for the degradation of vehicle exhaust (VE) has been constructed using a waterborne acrylic acid emulsion as the coating substrate; Fe/N/Co–TiO2 nanoparticles (NPs) as photocatalytic components; and water, pigments, and fillers as additives. The visible-light-responsive Fe/N/Co–TiO2 NPs with an average size of 100 nm were prepared by sol-gel method firstly. The co-doping of three elements extended the absorption range of the modified TiO2 nanoparticles to the visible light region, and showed the highest light absorption intensity, which was confirmed by the ultraviolet-visible absorption spectra (UV-Vis). X-ray diffraction (XRD) measurements showed that element doping prevents the transition from anatase to rutile and increases the transition temperature. TiO2 was successfully doped due to the reduction of the chemical binding energy of Ti, as revealed by X-ray photoelectron spectroscopy (XPS). The degradation rates of NOX, CO, and CO2 in VE by Fe/N/Co–TiO2 NPs under visible light were 71.43%, 23.79%, and 21.09%, respectively. In contrast, under the same conditions, the degradation efficiencies of coating for VE decreased slightly. Moreover, the elementary properties of the coating, including pencil hardness, adhesive strength, water resistance, salt, and alkali resistance met the code requirement. The photocatalytic coating exhibited favorable reusability and durability, as shown by the reusability and exposure test.

Black TiO2 nanoparticles with efficient photocatalytic activity under visible light at low temperature: regioselective C–N bond cleavage toward the synthesis of thioureas, sulfonamides, and propargylamines

2020 ◽  
Vol 10 (20) ◽  
pp. 6825-6839 ◽  
Author(s):  
Mehdi Koohgard ◽  
Mona Hosseini-Sarvari
Keyword(s):  
Photocatalytic Activity ◽  
Low Temperature ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Bond Cleavage ◽  
Regioselective Synthesis ◽  
Tertiary Amines ◽  
Black Tio2

Several different colored forms of TiO2 were prepared through the easy treatment of white TiO2 and NaBH4 as a safe hydrogen source. Then, tertiary amines were harnessed toward the regioselective synthesis of three prominent scaffolds.

Phytochemical composition and antioxidant activity of Malus baccata (L.) Borkh. fruits

2020 ◽  
Vol 3 (1) ◽  
pp. 47
Author(s):  
Nadezhda Petkova ◽  
Manol Ognyanov ◽  
Blaga Inyutin ◽  
Petar Zhelev ◽  
Panteley Denev
Keyword(s):  
Phenolic Compounds ◽  
Antioxidant Activities ◽  
Ethanol Extract ◽  
Titratable Acidity ◽  
Total Phenolic ◽  
Total Phenolic Compounds ◽  
Frap Assay ◽  
Phytochemical Composition ◽  
Malus Baccata

Crab apple (Malus baccata (L.) Borkh.) was mainly distributed in Europe as an ornamental plant, but the nutritional properties of its edible fruits were not fully revealed. The aim of the current study was to characterize the phytochemical composition of ripen carb apple fruits and to evaluate their nutritional and antioxidant potentials. The fruits were assayed for moisture and ash content, proteins, lipids, carbohydrates, titratable acidity (TA), pH, total phenolic compounds and natural pigments. Among the analyzed carbohydrates cellulose was found in the highest content (6% dw), followed by sugars (sucrose, glucose and fructose) and 1.8 % dw uronic acids. The total chlorophylls and carotenoids contents in their fruits were 6.51 and 4.80 μg/g fw, respectively. Total monomeric anthocyanins were not detected. The highest content of total phenolic compounds (2.67 mg GAE/g fw) was found in 95 % ethanol extract from fruits, while the total flavonoids were relatively low – 0.1 mg QE/g fw. DPPH assay (17.27 mM TE/g fw) and FRAP assay (14.34 mM TE/g fw) demonstrated in vitro antioxidant activities of crabapple. Malus baccata fruits were evaluated as a rich source of dietary fibers and phenolic compounds with significant antioxidant potential that could be used in human nutrition.

Survey of Chinese Cowpea Cultivars for Phenolic Compounds and Antioxidant Activity

2018 ◽  
Vol 17 (4) ◽  
pp. 337-348
Author(s):  
Bai Zhouya ◽  
Huang Xiaojun ◽  
Meng Jinxia ◽  
Kan Lijiao ◽  
Nie Shaoping
Keyword(s):  
Phenolic Compounds ◽  
Phenolic Content ◽  
Antioxidant Activities ◽  
Jiangxi Province ◽  
Total Phenolic ◽  
Total Flavonoid Content ◽  
Flavonoid Content ◽  
Comprehensive Investigation ◽  
Cowpea Cultivars ◽  
P Distribution

Distribution of phenolic compounds and antioxidant activities was surveyed in 24 varieties of Chinese cowpea from 4 provinces. Identity of phytochemicals were determined by UPLC-ESIQTOF-MS/MS and quantified by HPLC-ESI-QqQ-MS/MS. Seven phenolic acids, 16 flavonoids and 9 other compounds were identified and several of these were quantified. Quercetin-3-glucoside and kaempferol-glucoside were the major phenolic compounds. In addition, our study indicated that OJYDH cultivar from Jiangxi province had the highest total phenolic content, total flavonoid content and stronger antioxidant activities than other cowpea cultivars. This study made a comprehensive investigation on antioxidants from cowpea and provided the useful data to support its function.

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