Publications by authors named "T Pazhanivel"

6 Publications

An efficient and magnetically recoverable g-CN/ZnS/CoFeO nanocomposite for sustainable photodegradation of organic dye under UV-visible light illumination.

Environ Res 2021 Jun 17;201:111429. Epub 2021 Jun 17.

Advanced Materials Research Chair, Chemistry Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.

Effective improvement of an easily recoverable photocatalyst is equally vital to its photocatalytic performance from a practical application view. The magnetically recoverable process is one of the easiest ways, provided the photocatalyst is magnetically strong enough to respond to an external magnetic field. Herein, we prepared graphitic carbon nitride nanosheet (g-CN), and ZnS quantum dots (QDs) supported ferromagnetic CoFeO nanoparticles (NPs) as the gCN/ZnS/CoFeO nanohybrid photocatalyst by a wet-impregnation method. The loading of CoFeO NPs in the g-CN/ZnS nanohybrid resulted in extended visible light absorption. The ferromagnetic g-CN/ZnS/CoFeO nanohybrid exhibited better visible-light-active photocatalytic performance (97.11%) against methylene blue (MB) dye, and it was easily separable from the aqueous solution by an external bar magnet. The g-CN/ZnS/CoFeO nanohybrid displayed excellent photostability and reusability after five consecutive cycles. The favourable band alignment and availability of a large number of active sites affected the better charge separation and enhanced photocatalytic response. The role of active species involved in the degradation of MB dye during photocatalyst by g-CN/ZnS/CoFeO nanohybrid was also investigated. Overall, this study provides a facile method for design eco-friendly and promising g-CN/ZnS/CoFeO nanohybrid photocatalyst as applicable in the eco-friendly dye degradation process.
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http://dx.doi.org/10.1016/j.envres.2021.111429DOI Listing
June 2021

Visible light driven reduced graphene oxide supported ZnMgAl LTH/ZnO/g-CN nanohybrid photocatalyst with notable two-dimension formation for enhanced photocatalytic activity towards organic dye degradation.

Environ Res 2021 06 26;197:111079. Epub 2021 Mar 26.

Chemistry Department P. O. Box 84428, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, 11671, Saudi Arabia.

In this study, 2D/2D/2D heterostructured r-GO/LTH/ZnO/g-CN nanohybrid were synthesized through hydrothermal method. The strong electrostatic interaction between the negatively charged g-CN and r-GO nanosheets with positively charged layered triple hydroxide (LTH) nanosheets are effectively influences the successful formation of heterojunction. The LTH nanosheets are well spread on the g-CN nanosheets combined with r-GO. In particular, the as prepared heterojunction shows a better photocatalytic degradation activity compared to pristine samples and the significant enhancement in the photocatalytic performance is mainly accredited to the large interfacial charge transition of photogenerated charge carriers under the visible light irradiation. Although the 2D/2D/2D heterojunction effectively hinders the charge carrier recombination resulting high photocatalytic activity with good stability. In addition, the r-GO supported LTH/ZnO/g-CN heterojunction shows high photo-stability after sequential experimental runs with no obvious change in the dye degradation process. Consequently, the role of active species was investigated over the r-GO/LTH/ZnO/g-CN heterojunction with the help of different scavengers.
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http://dx.doi.org/10.1016/j.envres.2021.111079DOI Listing
June 2021

Construction of magnetically recoverable ZnS-WO-CoFeO nanohybrid enriched photocatalyst for the degradation of MB dye under visible light irradiation.

Chemosphere 2021 Jun 19;273:129687. Epub 2021 Jan 19.

Department of Physics, Vellore Institute of Technology (Amaravati Campus), Amaravati, 522501, Guntur, Andhra Pradesh, India.

Easily recyclable photocatalysts have received considerable attention for their practical application, in order to address the wastewater treatments. Here, we report efficient and magnetically recyclable ZnS-WO-CoFeO nanohybrid prepared through wet impregnation method. The photophysical and optical properties of as-prepared photocatalysts was investigated by different spectroscopic techniques. The photocatalytic activity of as synthesized samples were assessed by the photodegradation of methylene blue (MB) dye under visible light irradiation. Amongst, ZnS-WO-CoFeO nanohybrid exhibit higher photodegradation activity than the other bare and hybrid samples. The enhanced light absorption and lower emission intensity provide the improved photocatalytic activity of ZnS-WO-CoFeO nanohybrid. The ZnS-WO-CoFeO nanohybrid exhibit excellent photostability after four consecutive cycles. The ferromagnetic behavior of the hybrid sample using easily recover from the dye solution using an external bar magnet.
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http://dx.doi.org/10.1016/j.chemosphere.2021.129687DOI Listing
June 2021

Kinetics and degradation of camphene with OH radicals and its subsequent fate under the atmospheric O and NO radicals - A theoretical study.

Chemosphere 2021 Mar 11;267:129250. Epub 2020 Dec 11.

Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan, BE1410, Brunei Darussalam.

Camphene (CH) is an abundant bicyclic monoterpene in the atmosphere which can be easily oxidized by the atmospheric OH radicals. In this study, the oxidation of camphene with OH radicals and its subsequent reactions are studied using quantum chemical method. Thermochemical parameters show that the addition of OH radicals to the terminal C10 atom of camphene is thermodynamically more stable than the addition of OH radicals to the internal C7 atom of camphene. The reaction force profile demonstrates that the formation of two hydroxyalkoxy radical intermediates (I1a and I2a) are mainly dominated by the structural rearrangement with 94.28% and 99.43% of the total energy, respectively. The overall reaction rate coefficient for camphene + OH radical is 2.1⨯10 cm molecule sec at 298 K and 1 atm which agree well with the experimental reaction rate coefficient (5.58⨯10 cm molecule sec) for the reaction of camphene with OH radical. The branching ratio for the addition of OH radical to the C10 position of camphene is 68.32%, and the C7 position of camphene is 31.68% at 298 K. The calculated lifetime reveals that camphene degrades quickly in the atmosphere owing to its short lifetime of 5.3 h. The obtained mechanistic and kinetic results reveal that the addition of OH radical to the C10 position is more dominant than the C7 position, and it is more stable and spontaneous in the atmosphere.
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http://dx.doi.org/10.1016/j.chemosphere.2020.129250DOI Listing
March 2021

Designed assembly of Ni/MAX (TiAlC) and porous graphene-based asymmetric electrodes for capacitive deionization of multivalent ions.

Chemosphere 2021 Mar 21;266:129048. Epub 2020 Nov 21.

Department of Chemical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates. Electronic address:

The contamination of aquatic ecosystems by fluoride and heavy metal ions constitute an environmental hazard and has been proven to be harmful to human health. This study explores the feasibility of using asymmetric capacitive deionization (CDI) electrodes to remove such toxic ions from wastewater. An asymmetric CDI cell was fabricated using 2D Ni/MAX as an anode and 3D porous reduced graphene oxide (pRGO) as a cathode for the electrosorption of F, Pb, and As(III) ions. A simple microwave process was used for the synthesis of Ni/MAX composite using fish sperm DNA (f-DNA) as a cross-linker between MAX nanosheets (NSs) and the metallic Ni nanoparticles (NPs). Further, pRGO anode was prepared through effective reduction of RGO using lemon juice as green reducing agent with the assist of f-DNA as a structure-directing agent for the formation of 3D network. With this tailored nanoarchitecture, pRGO and Ni/MAX electrodes exhibited a high specific capacitance of 760 and 385 F g, respectively. The fabricated Ni/MAX and pRGO based CDI system demonstrated a high electrosorption capacity of 68, 76, and 51 mg g for the monovalent F, divalent Pb, and trivalent As(III) ions at 1.4 V in neutral pH. Furthermore, Ni/MAX//pRGO system was successfully applied for the removal of total F(T), Pb(T), and As(T) ions from real industrial wastewater and contaminated groundwater. The present findings indicate that the fabricated Ni/MAX//pRGO electrode has excellent electrochemical properties that can be exploited for the removal of anionic and cationic metal ions from aqueous solutions in a CDI based system.
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http://dx.doi.org/10.1016/j.chemosphere.2020.129048DOI Listing
March 2021
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