Fluorescent carbon dot decorated MnO2 nanorods for complete photomineralization of phenol from water

2018 ◽  
Vol 4 (12) ◽  
pp. 2012-2020 ◽  
Author(s):  
Akansha Mehta ◽  
Amit Mishra ◽  
Soumen Basu
Keyword(s):  
Photocatalytic Degradation ◽  
Rate Constant ◽  
Phenol Degradation ◽  
Degradation Efficiency ◽  
High Rate ◽  
Operational Parameters ◽  
Carbon Dot ◽  
Fluorescent Carbon

Using MnO2@CQDs the photocatalytic degradation of phenol was tested and under optimum operational parameters, phenol degradation efficiency was found to be ∼90% with a high rate constant R = 0.029 min−1.

Facile one pot synthesis of zinc oxide nanorods and statistical evaluation for photocatalytic degradation of a diazo dye

2016 ◽  
Vol 74 (3) ◽  
pp. 698-713 ◽  
Author(s):  
Suvanka Dutta ◽  
Ananya Ghosh ◽  
Humayun Kabir ◽  
Rajnarayan Saha
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Degradation ◽  
Band Gap Energy ◽  
Degradation Efficiency ◽  
Zinc Oxide Nanorods ◽  
Operational Parameters ◽  
One Pot ◽  
Oxide Nanorods ◽  
Total Treatment ◽  
Diazo Dye

In the present work zinc oxide nanorods (ZNRs) have been synthesized to estimate its photocatalytic degradation potential on an industrially used diazo dye and optimization of the total treatment process has been designed. Response surface methodology (RSM) has been used to model the operational parameters for this photocatalytic degradation. The crystallite size (101 plane) of the synthesized ZNR has been found to be 20.99 nm having a band gap energy of 3.45 eV. At elevated pH, the rate of degradation of the photocatalyst was found to be higher than that of acidic pH. The independent variables of the model are time (9.6–122 min), pH (2–12.2), catalyst dose (0.2–0.4 g/L) and dye concentration (88–512 mg/L). It was seen that the degradation efficiency was significantly affected by the initial dye concentration and the pH, the optimal values of the parameters being a pH of 10.67, an initial concentration of 150 mg/L and ZnO dose of 0.37 g/L, the time taken being 88.52 min. The actual degradation efficiency of the dye reached 96.9% at optimized condition, which is quite close to the predicted value of 98.07%.

scholarly journals ZnCDs/ZnO@ZIF-8 Zeolite Composites for the Photocatalytic Degradation of Tetracycline

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 934
Author(s):  
Yong Cheng ◽  
Xiuxiu Wang ◽  
Yu Mei ◽  
Dan Wang ◽  
Changchun Ji
Keyword(s):  
Catalytic Activity ◽  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Active Species ◽  
Degradation Efficiency ◽  
Experimental Result ◽  
Porous Nanostructure ◽  
Resultant Material

Considering the photocatalytic performance of CDs, ZnO, and the unique porous nanostructure and stability of ZIF-8, we prepared ZnCDs/ZnO@ZIF-8 zeolite composites. The resultant material represented an enhanced ability for the photodegradation of TC compared with that of ZnCDs and ZnO. The photocatalytic degradation efficiency reached over 85%. The catalytic activity of the composites was maintained after four cycles. The experimental result indicated that ×O2 radical was the active species in the reaction.

scholarly journals Photocatalytic Degradation of Malachite Green Dye from Aqueous Solution Using Environmentally Compatible Ag/ZnO Polymeric Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2033
Author(s):  
Marwa F. Elkady ◽  
Hassan Shokry Hassan
Keyword(s):  
Photocatalytic Degradation ◽  
Malachite Green ◽  
Degradation Efficiency ◽  
Solution Flow Rate ◽  
Gravimetric Analysis ◽  
Electrospinning Technique ◽  
Malachite Green Dye ◽  
Polymeric Nanofibers ◽  
Before And After ◽  
Surface Modified

An efficient, environmentally compatible and highly porous, silver surface-modified photocatalytic zinc oxide/cellulose acetate/ polypyrrole ZnO/CA/Ppy hybrid nanofibers matrix was fabricated using an electrospinning technique. Electrospinning parameters such as solution flow rate, applied voltage and the distance between needles to collector were optimized. The optimum homogenous and uniform ZnO/CA/Ppy polymeric composite nanofiber was fabricated through the dispersion of 0.05% wt ZnO into the dissolved hybrid polymeric solution with an average nanofiber diameter ranged between 125 and 170 nm. The fabricated ZnO-polymeric nanofiber was further surface-immobilized with silver nanoparticles to enhance its photocatalytic activity through the reduction of the nanofiber bandgap. A comparative study between ZnO polymeric nanofiber before and after silver immobilization was investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA). The photocatalytic degradation efficiency of the two different prepared nanofibers before and after nanosilver immobilization for malachite green (MG) dye was compared against various experimental parameters. The optimum degradation efficiency of nanosilver surface-modified ZnO-polymeric nanofibers was recorded as 93.5% for malachite green dye after 1 h compared with 63% for ZnO-polymeric nanofibers.

Performance of Photocatalytic Microfiltration with Hollow Fiber Membrane

2007 ◽  
Vol 544-545 ◽  
pp. 95-98 ◽  
Author(s):  
Jong Tae Jung ◽  
Jong Oh Kim ◽  
Won Youl Choi
Keyword(s):  
Heavy Metals ◽  
Humic Acid ◽  
Rate Constant ◽  
Hollow Fiber ◽  
Reaction Rate ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Reaction Rate Constant ◽  
Operational Parameters ◽  
Tio2 Particles

The purpose of this study is to investigate the effect of the operational parameters of the UV intensity and TiO2 dosage for the removal of humic acid and heavy metals. It also evaluated the applicability of hollow fiber microfiltration for the separation of TiO2 particles in photocatalytic microfiltration systems. TiO2 powder P-25 Degussa and hollow fiber microfiltration with a 0.4 μm nominal pore size were used for experiments. Under the conditions of pH 7 and a TiO2 dosage 0.3 g/L, the reaction rate constant (k) for humic acid and heavy metals increased with an increase of the UV intensity in each process. For the UV/TiO2/MF process, the reaction rate constant (k) for humic acid and Cu, with the exception of Cr in a low range of UV intensity, was higher compared to that of UV/TiO2 due to the adsorption of the membrane surface. The reaction rate constant (k) increased as the TiO2 dosage increased in the range of 0.1~0.3 g/L. However it decreased for a concentration over 0.3 g/L of TiO2. For the UV/TiO2/MF process, TiO2 particles could be effectively separated from treated water via membrane rejection. The average removal efficiency for humic acid and heavy metals during the operational time was over 90 %. Therefore, photocatalysis with a membrane is believed to be a viable process for humic acid and heavy metals removal.

The Effect of Operational Parameters on the Photocatalytic Mineralization of Indocorn Brilliant Red M5B Using Sol–gel Derived Nanostructured Zinc Titanate as an Efficient Photocatalyst

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Maryam Mikhak
Keyword(s):  
Azo Dye ◽  
Sol Gel ◽  
Degradation Efficiency ◽  
High Yield ◽  
Operational Parameters ◽  
Solution Ph ◽  
Zinc Titanate ◽  
First Order Kinetics ◽  
Size Uniformity ◽  
One Step

AbstractNanostructured zinc titanate (NZT) was synthesized in high yield via a one-step and template-free sol-gel route. The prepared nanocomposite exhibited good size uniformity and regularity. The enhanced photocatalytic activity of the NZT was evaluated in the degradation and mineralization of Indocorn Brilliant Red (M5B) under metal halide lamp irradiation. The effects of different parameters such as pH of the solution, and initial dye concentration on photodegradation of M5B were analyzed. The degradation of M5B follows pseudo-first order kinetics according to the Langmuir-Hinshelwood model. The experimental results showed that the initial concentration of azo dye in the dye mixture greatly affected the degradation efficiency. At M5B concentrations of 10 mg/L, the optimum conditions for the highest degradation efficiency (94%) of azo dye were a photocatalyst dosage of 0.01 g/L and an initial solution pH of 9. This study provided new insight into the design and preparation of nanomaterial demonstrated an excellent ability to remove organic pollutants in wastewater.

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