Kannappan Lakshmi

Scopus Publications

Nanocatalysts and Redox Nanoparticles for Water Purification
Kannappan Lakshmi, Arunasalam Sridhar, Rajmohan Rangasamy
Nanomaterials for Air and Water Purification, 2024
Generally, water purification using nanomaterials involves adsorption, oxidation, and reduction. Among these processes, nanomaterials as catalysts are more prominent, as they not only remove or degrade the organic pollutants during the process of purification but also convert hazardous contaminants into nontoxic or useful pharmaceutical products. This chapter deals with nanomaterials and redox nanomaterials that are utilized as nanocatalyst in water purification. Nanocatalysts are mostly carbon-based materials, metal nanoparticles, metal oxide nanoparticles, and redox nanomaterials such as Fenton reagent and zero-valent iron nanoparticles.
E laeocarpus Sylvestris mediated green approach for fabrication of magnetite nanoparticles: Antimicrobial and antioxidant potentialities
G. Tejaswini, Sk. Beebi, G. Meher Baba, G. Sanyasinaidu, K. Bhagya Lakshmi
Applied Nanoscience Switzerland, 2023
Rose Bengal Anchored Silica-Magnetite Nanocomposite as Photosensitizer for Visible- Light-Mediated Oxidation of Thioethers
Edwin Prathibha, Rajmohan Rangasamy, Arunasalam Sridhar, Kannappan Lakshmi
Journal of Cluster Science, 2023
Ultrasound-assisted synthesis of silica-coated magnetite material decorated with silver nanoparticles for the detoxification of 4-nitrophenol
Edwin Prathibha, Rajmohan Rangasamy, Arunasalam Sridhar, Kannappan Lakshmi
Applied Organometallic Chemistry, 2023
Among phenolic pollutants, 4‐nitrophenol is a common organic pollutant readily discharged in water bodies. It causes an adverse effect on the lives of human beings and aquatic species. Therefore, it is essential to remove this pollutant from water resources. Herein, we report an eco‐friendly approach for the synthesis of silica‐coated magnetite material decorated with ultra‐fine silver nanoparticles, as a magnetically recyclable catalyst for the detoxification of 4‐nitrophenol. This synthetic strategy employs only ultrasound waves throughout the preparation of catalyst material. Further, no stabilizer was added in any of the steps involved in synthesis. Initially, iron oxide nanoparticles were synthesized from ferrous sulphate heptahydrate precursor and coated with silica matrix. Subsequently, silver nanoparticles were deposited over it. Silver was chosen among the noble metal nanoparticles, as it is abundantly available and economical and exhibits good catalytic properties. This catalyst material was well characterized using HRTEM, XRD, VSM and FTIR techniques. HRTEM studies revealed that Ag nanoparticles of size between 2 and 5 nm were dispersed over the silica‐coated magnetite. The significant merits of this approach are usage of ultrasound waves, stabilizer‐free and reduced time consumption in the synthesis of catalyst. Furthermore, a facile magnetic separation of catalyst using bar magnet is noteworthy to this method. The catalyst was successfully recycled for eight times without any significant loss in the activity. This can be a promising catalyst for the treatment of wastewater contaminated with 4‐nitrophenol.
A Comprehensive Review on Green Synthetic Approaches and Applications of 3d-Series Metal Oxide Nanoparticles
G. Tejaswini, P. Lakshmi Kishore, V. Naga Lakshmi, K. Bhagya Lakshmi
Asian Journal of Chemistry, 2022
Transition metal oxides have been studied by many workers of fields who want to find new ways to use them in medical devices and other fields. Researchers have done a lot of research on solid-state synthesis methods, which require high temperatures and make molecules that are thermodynamically stable. Transition metal oxides have been used for a wide range of things, from nanoparticles that deliver drugs to systems that store information in more than one state. In materials science and technology research and development, a new era of “green synthesis” methods is getting a great attention. Basically, green synthesis of materials and nanomaterials, which is done through a process of regulation, control, cleaning and remediation, will directly help make them more friendly to the environment. In this review, various green approaches for 3d-series metal oxide nanoparticles and their applications are discussed.
Sustainable catalysis of nanocrystals: A green technology
Rajmohan Rangasamy, Kannappan Lakshmi, Karuppiah Muthu
Industrial Applications of Nanocrystals, 2022
Synthesis of ultrafine AuPd bimetallic nanoparticles using a magnetite-cored poly(propyleneimine) dendrimer template and its sustainable catalysis of the Suzuki coupling reaction
Rajmohan Rangasamy, Kannappan Lakshmi, Mari Selvaraj
New Journal of Chemistry, 2021
A rational synthesis of magnetically recyclable PPI dendrimer encapsulated AuPd bimetallic nanoparticle and its catalytic examination in the Suzuki coupling reaction.
Synthetic modification of silica coated magnetite cored PAMAM dendrimer to enrich branched Aaine groups and peripheral carboxyl groups for environmental remediation
Kannappan Lakshmi, Rajmohan Rangasamy
Journal of Molecular Structure, 2021
Dendrimer with amine groups have several applications in gene delivery, drug delivery, metal encapsulation for catalysis and environmental remediation. Specifically, dendrimers having enriched amino groups with accessible void makes significant impact in the above fields. Besides, the carboxylic acid terminated amine dendrimers may enhance the efficacy as well. Therefore, herein we report the synthetic modification of poly(amidoamine) G3 dendrimer with magnetite core to enrich branched amine groups and peripheral carboxyl groups. To deliver this nanohybrid material, for the first-time silica coated magnetite cored poly(amidoamine) G3 dendrimer was synthesized by microwave assisted method. Subsequently amide groups present in the PAMAM have been reduced using lithium aluminum hydride to yield polyamine dendrimer namely poly (N-propylethane-1,2-diamine) G3. Further, peripheral amine groups were grafted with succinic anhydride to achieve carboxylic acid terminated dendrimer. The resulting nanomaterial was confirmed by FTIR, XRD, VSM, TGA, HRTEM and conductometry methods. In order to emphasize the structural efficacy of polyamine dendrimer, the metal ion uptake behavior has been discussed for the representative cations such as Pb2+, Cu 2+, Cr6+, Ca2+ and Ni2+ under the environmental concern. Magnetite cored polyamine dendrimer had evaluated for its recyclability test in the subsequent metal ion uptake studies and found to be satisfactory.
Synthesis and Characterization of Fe3O4/Carbon Dot Supported MnO2 Nanoparticles for the Controlled Oxidation of Benzyl Alcohols
Edwin Prathibha, Rajmohan Rangasamy, Arunasalam Sridhar, Kannappan Lakshmi
Chemistryselect, 2020
Abstract In recent past, magnetic catalyst has gained much attention because it can be easily separated from the reaction mixture. Herein we report a facile synthesis of magnetic carbon dot supported MnO 2 nanoparticles for the oxidative transformation of organic compounds. In the actual synthesis, initially Fe 3 O 4 nanoparticles were prepared by microwave assisted method and carbon dots were prepared instantaneously from glucose by simple incineration under closed condition. The synthesized carbon dots were coated over iron oxide nanoparticles via sonochemical deposition method. Further, magnetic carbon dot supported MnO 2 nanocomposite was synthesized by conventional homogeneous precipitation using potassium permanganate. The synthesized nanocomposite material was characterized using FT‐IR, SEM, TEM, XRD and VSM techniques. The catalytic efficiency of the nanomaterial was successfully demonstrated for the oxidation of benzyl alcohols to benzaldehydes. The advantages of this method include, controlled oxidation of alcohols to aldehydes with broad substrate scope, the use of molecular oxygen as a green oxidant and beyond that a facile magnetic separation of the catalyst material. Moreover, the catalyst can be recycled for 5 times without much loss in its efficiency.
Immobilization of Pt nanoparticles on magnetite–poly (epoxyamine) nanocomposite for the reduction of p-nitrophenol
Kannappan Lakshmi, Rajmohan Rangasamy, E. Prathibha, A. Sridhar
SN Applied Sciences, 2019
Recently the magnetic nanoparticle earns more attention in the field of catalysis for their enhanced loading capacity and magnetic recylability. In this study, we intended to focus the synthesis of polymer coated iron oxide nanoparticle as support for the immobilization of metal nanoparticles. The typical synthetic statergy involves the synthesis of 1,4-diaminobutane functionalized superparamagnetic Fe3O4 nanoparticle, followed by epoxyamine polymer coating on amine functionalised Fe3O4 using 1,4 diaminobutane and epichlorohydrin monomers through one pot method. Further, ultrafine Pt nanoparticle was immobilised onto poly (epoxyamine) coated Fe3O4. These materials were characterized using FT-IR, XRD, VSM, EDS, SEM HRTEM etc. The semiheterogenous catalytic efficiency of the material was examined in aqueous phase reduction of p-nitrophenol. The catalyst was reused up to 5 times without loss of activity.Graphic abstract