scholarly journals Visible Domain Photocatalysis Performance of Ti-Si Thermal-Sprayed Coatings

2021 ◽  
Vol 14 (1) ◽  
pp. 85
Author(s):  
Ionut Uncu ◽  
Ionut Claudiu Roata ◽  
Catalin Croitoru ◽  
Teodor Machedon-Pisu
Keyword(s):  
Visible Light ◽  
Thermal Spraying ◽  
Silicon Powder ◽  
Plain Carbon Steel ◽  
Blue Dye ◽  
Order Kinetic ◽  
Step Method ◽  
Reaction Rate Constants ◽  
And Performance ◽  
Materials Used

Cost and performance-effective materials used in advanced oxidation processes such as photocatalysis have obtained widespread attention in recent years. In this study, thermal spraying was used as a one-step method to obtain thick visible-light-active photocatalyst coatings on two types of substrates, namely, plain carbon steel and copper. A mixed metallic titanium–silicon powder bearing 10% wt. Si was used as feedstock. The optical bandgaps of the coatings were close to 1.000 eV, allowing good photodecoloration efficiencies (>89%) and mineralization efficiencies (>67%) for methylene blue dye from aqueous solutions under visible light irradiation. The photodegradation process could be successfully modelled by the Langmuir–Hinshelwood pseudo-first-order kinetic model, with reaction rate constants k between 0.16 and 1.06 h−1.

Using of modified-bentonite as low-cost sorbent for removal of methylene blue dye from aqueous solution

2020 ◽  
Vol 27 (2) ◽  
pp. 45-54
Author(s):  
Saraa Muwafaq Ibrahim ◽  
Ziad T. Abd Ali
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Silanol Group ◽  
Infrared Spectrometry ◽  
Blue Dye ◽  
Ammonium Bromide ◽  
Vibration Band ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Modified Bentonite

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.

scholarly journals Adsorption and Photocatalytic Mineralization of Bromophenol Blue Dye with TiO2 Modified with Clinoptilolite/Activated Carbon

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Emmanuel Kweinor Tetteh ◽  
Sudesh Rathilal
Keyword(s):  
Activated Carbon ◽  
Photocatalytic Degradation ◽  
Oxygen Demand ◽  
Freundlich Isotherm ◽  
Reaction Rate Constant ◽  
Coefficient Of Determination ◽  
Bromophenol Blue ◽  
Blue Dye ◽  
Order Kinetic ◽  
Co Precipitation

This study presents a hybridized photocatalyst with adsorbate as a promising nanocomposite for photoremediation of wastewater. Photocatalytic degradation of bromophenol blue (BPB) in aqueous solution under UV-irradiation of wavelength 400 nm was carried out with TiO2 doped with activated carbon (A) and clinoptilolite (Z) via the co-precipitation technique. The physiochemical properties of the nanocomposite (A–TiO2 and Z–TiO2) and TiO2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. Results of the nanocomposite (A–TiO2 and Z–TiO2) efficiency was compared to that with the TiO2, which demonstrated their adsorption and synergistic effect for the removal of chemical oxygen demand (COD) and color from the wastewater. At an optimal load of 4 g, the photocatalytic degradation activity (Z–TiO2 > A–TiO2 > TiO2) was found favorably by the second-order kinetic model. Consequently, the Langmuir adsorption isotherms favored the nanocomposites (Z–TiO2 > A–TiO2), whereas that of the TiO2 fitted very well on the Freundlich isotherm approach. Z–TiO2 evidently exhibited a high photocatalytic efficacy of decomposition over 80% of BPB (COD) at reaction rate constant (k) and coefficient of determination (R2) values of 5.63 × 10−4 min−1 and 0.989, respectively.

Facile synthesis, characterize, mechanism and enhanced visible-light photocatalytic of SiW12/α-Fe2O3 nanocomposite

2021 ◽  
Author(s):  
Haihui Yu ◽  
Bing Wei ◽  
Junping Wang ◽  
Sai Zeng ◽  
Haiqi Zhao ◽  
...  
Keyword(s):  
Visible Light ◽  
Facile Synthesis ◽  
Step Method ◽  
Visible Light Photocatalytic

A novel type of photocatalyst SiW12/α-Fe2O3 created by combining SiW12 NPs and α-Fe2O3 nanorings was synthesized through “step to step” method. The structure, composition, morphology and the interaction between SiW12...

scholarly journals Selective growth of Ti3+/TiO2/CNT and Ti3+/TiO2/C nanocomposite for enhanced visible-light utilization to degrade organic pollutants by lowering TiO2-bandgap

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeasmin Akter ◽  
Md. Abu Hanif ◽  
Md. Akherul Islam ◽  
Kamal Prasad Sapkota ◽  
Jae Ryang Hahn
Keyword(s):  
Visible Light ◽  
Structural Integrity ◽  
Carbon Layer ◽  
Wide Bandgap ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Excellent Photocatalytic Activity ◽  
Convenient Route ◽  
Walled Carbon Nanotubes

AbstractA convenient route was developed for the selective preparation of two stable nanocomposites, Ti3+/TiO2/CNT (labeled as TTOC-1 and TTOC-3) and Ti3+/TiO2/carbon layer (labeled as TTOC-2), from the same precursor by varying the amount of single-walled carbon nanotubes used in the synthesis. TiO2 is an effective photocatalyst; however, its wide bandgap limits its usefulness to the UV region. As a solution to this problem, our prepared nanocomposites exhibit a small bandgap and wide visible-light (VL) absorption because of the introduction of carbonaceous species and Ti3+ vacancies. The photocatalytic efficiency of the nanocomposites was examined via the degradation of methylene blue dye under VL. Excellent photocatalytic activity of 83%, 98%, and 93% was observed for TTOC-1, TTOC-2, and TTOC-3 nanocomposites within 25 min. In addition, the photocatalytic degradation efficiency of TTOC-2 toward methyl orange, phenol, rhodamine B, and congo red was 28%, 69%, 71%, and 91%, respectively, under similar experimental conditions after 25 min. Higher reusability and structural integrity of the as-synthesized photocatalyst were confirmed within five consecutive runs by photocatalytic test and X-ray diffraction analysis, respectively. The resulting nanocomposites provide new insights into the development of VL-active and stable photocatalysts with high efficiencies.

Low-temperature processed inorganic perovskites for flexible detectors with a broadband photoresponse

Nanoscale ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 2871-2877 ◽  
Author(s):  
Ting Zhang ◽  
Feng Wang ◽  
Peng Zhang ◽  
Yafei Wang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Visible Light ◽  
Environmental Stability ◽  
Step Method ◽  
Broadband Spectrum ◽  
One Step ◽  
Spectrum Response

The flexible perovskite photodetector, fabricated by a modified one-step method, showed a broadband spectrum response from blind ultraviolet to visible light, and exhibited excellent mechanical flexibility and improved environmental stability.

Research highlights: visible light driven photocatalysis and photoluminescence and their applications in water treatment

2016 ◽  
Vol 2 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Qinmin Zheng ◽  
David T. Tan ◽  
Danmeng Shuai
Keyword(s):  
Water Treatment ◽  
Visible Light ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Red Phosphorus ◽  
Visible Light Driven ◽  
Innovative Materials ◽  
Materials Used

We discuss three innovative materials used in photocatalysis and photoluminescence for water treatment applications, including graphitic carbon nitride (g-C3N4), red phosphorus, and upconversion phosphors (Y2SiO5 doped with Pr and Li).

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