Sol–gel assembled ZnMn2O4/rGO nanocomposite for enhanced photocatalytic decomposition of tetracycline under visible light

Author(s):  
A. Baoum ◽  
M. S. Amin
2017 ◽  
Vol 17 (6) ◽  
pp. 1722-1729 ◽  
Author(s):  
Hesam Zamankhan Malayeri ◽  
Mallikarjuna Nadagouda ◽  
Hyeok Choi

Abstract Harmful algal blooms (HABs) found in various water bodies worldwide have been a huge concern due to their adverse impacts on human health and ecosystems. In particular, HABs associated with cyanobacteria have been of great interest because of their potential to generate and release biological toxins, especially, lethal microcystins (MCs). The overall goal of this study was to develop a new sustainable approach to decompose MCs, preferably on-site and in real-time with minimal effort, fewer chemicals, and low energy inputs. To achieve the goal, a high efficiency nitrogen-doped TiO2 photocatalytic film immobilized onto a glass substrate was fabricated via integrated sol-gel synthesis employing nitrogen-containing surfactants as pore-templating agent and nitrogen-dopant. The film exhibited visible light-activated, nanoporous, and transparent properties. Effects of surfactant type, calcination temperature, coating layers, and reaction pH on the photocatalytic decomposition of microcystin-LR (MC-LR) were investigated under visible light. Eventually, the TiO2 film was able to successfully decompose MC-LR on-site in a lake under solar radiation in real-time. This study implies the high potential of the TiO2 film for on-site and real-time decomposition of many organic contaminants in water by using sustainable solar energy.


2011 ◽  
Vol 239-242 ◽  
pp. 571-574
Author(s):  
Xiang Chao Zhang ◽  
Yun Long Li ◽  
Zhong Xin Lin ◽  
Shi Ying Zhang

A SiO2/TiO2 supported on glass fibers photocatalyst with visible light activity were synthesized by sol-gel technology, butyl titanate as a Ti source, and tetraethylorthosilicate (TEOS) as a Si source. The photocatalytic activitie under visible light of SiO2/TiO2 supported on glass fibers were evaluated by the photocatalytic decomposition of methylene blue. The samples were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS). The results show that the optical absorption edges of the SiO2/TiO2 showed red shift with increasing the dopant of SiO2. The sample of SiO2/TiO2 supported on glass fiber (atomic ratio of Si/Ti=0.05) has the highest catalytic efficiency under visible light irradiation.


2008 ◽  
Vol 281 (1-2) ◽  
pp. 93-98 ◽  
Author(s):  
Vicente Rodríguez-González ◽  
Rodolfo Zanella ◽  
Gloria del Angel ◽  
Ricardo Gómez

2017 ◽  
Vol 870 ◽  
pp. 418-423
Author(s):  
Chuya Ogawa ◽  
Kozo Taguchi

TiO2 has become a widely investigated photocatalyst because of its low cost, low toxicity and high photocatalytic activity under UV irradiation that causes photocatalytic decomposition of organic compounds. Impurities dopant and metal are often used to acquire impurities doped or metal doped TiO2 powder by a sol-gel method. In this paper, we made nitrogen doped TiO2 by a simple process. TiO2 (P25) thin films with 80 % of anatase and 20 % of rutile were fabricated on FTO glass by electrophoretic deposition (EPD). These were then doped with nitrogen by using urea and sintered in electric furnace at 500 and 600 degrees Celsius. EPD was superior for film formation at dispersibility. We calculated absorbance spectra of nitrogen doped TiO2 thin film fabricated on FTO glass. As the result, 600 degrees Celsius is superior sintering temperature at absorbance under visible light than 500 degrees Celsius. Moreover, when the samples sintered at 600 degrees Celsius, each additive amount had different increment of absorbance in specific visible light range. This result indicates the improvement in visible-light response on TiO2 by the simple process. To further research, it is essential to make nitrogen doped TiO2 under pressure and measure the photodegradation reaction.


Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1010
Author(s):  
Kyong-Hwan Chung ◽  
Byung-Joo Kim ◽  
Young-Kwon Park ◽  
Sang-Chai Kim ◽  
Sang-Chul Jung

Amorphous TiO2 doped with N was characterized by its photocatalytic activity under visible light irradiation. The amorphous N-doped TiO2 was prepared by the sol-gel method through heat treatment at a low temperature. The photocatalyst showing activity in visible light despite heat treatment at low temperature can be applied to plastics and has excellent utility. The N-doped TiO2 appeared amorphous when heat-treated at 130 °C. It was converted into an anatase-type N-doped TiO2 when this was calcined at 500 °C. The photocatalyst showed photocatalytic activities in the photocatalytic decomposition of formaldehyde and methylene blue under visible light irradiation. The photocatalyst exhibited a higher rate of hydrogen production than that of TiO2 in photocatalytic decomposition of water under liquid-phase plasma irradiation. The bandgap of the amorphous N-doped TiO2 measured by investigation of optical properties was 2.4 eV. The lower bandgap induced the photocatalytic activities under visible light irradiation.


Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.


RSC Advances ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 6383-6394 ◽  
Author(s):  
Haishuai Li ◽  
Linlin Cai ◽  
Xin Wang ◽  
Huixian Shi

A noval ternary nanocomposite AgCl/Ag3PO4/g-C3N4 was successfully synthesized for photocatalytic degradation of methylene blue, methylparaben and inactivation of E. coli under visible light irradiation, showing excellent photocatalytic degradation performance and stability.


Author(s):  
Nuha Elamin ◽  
A. Modwi ◽  
M. A. Ben Aissa ◽  
Kamal K. Taha ◽  
Omer K. Al-Duaij ◽  
...  

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.


Sign in / Sign up

Export Citation Format

Share Document