@article { ISI:000351435100014, title = {Microwave-assisted synthesis of few-layered TaTe2 and its application as supercapacitor}, journal = {European Journal of Inorganic Chemistry}, number = {9}, year = {2015}, month = {MAR}, pages = {1598-1603}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

We report a simple and rapid microwave-assisted synthesis of tantalum telluride (TaTe2) nanosheets. The ratio of tantalum pentachloride (TaCl5) and elemental tellurium (Te) powder were adjusted in the presence of NaBH4 in such a way as to obtain the TaTe2 nanosheet. The samples were characterized by various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), UV/Vis spectroscopy, photoluminescence (PL) spectroscopy, and XRD. Our SEM, TEM, and AFM results show the formation of sheet-like morphology, while the XRD data confirms the high crystalline quality and stable phase of the TaTe2 formed. The supercapacitor cells were fabricated by using TaTe2 nanosheets as anode material, platinum metal wire as a counterelectrode, and Ag/AgCl as reference electrode. The calculated coulombic efficiency is more than 95\%, while the cycle-to-cycle decrease in capacity is less than 5\%. The maximum discharge or charging capacity is below 2.4 Wh/kg, which is an ideal characteristic for achieving supercapacitor behavior.

}, keywords = {Microwave chemistry, Nanostructures, Supercapacitors, Tantalum, Tellurium}, issn = {1434-1948}, doi = {10.1002/ejic.201403220}, author = {Chakravarty, Disha and Kumar, Praveen and Ugale, Vaishali S. and Late, Dattatray J.} } @article {45499, title = {Synthesis of nanogate structure in GO-ZnS sandwich material}, journal = {Scientific Reports}, volume = {9}, year = {2019}, month = {JAN}, pages = {Article Number: 937}, type = {Article}, abstract = {

Graphite Oxide (multi-layer) composite with other materials has a huge application in various field of science, due to its excellent and unique properties. Even though from past decade, immense research has been done by materials scientists in this field, but the chemistry is still not yet satisfactory. Here, in this work, through the discovery of Nanogate structure, we have reported for the first time the experimental results that enlightened the clear chemistry between the GO and ZnS which is further supported by the DFT calculations. This novel synthesis method led to the discovery of nanogate structure sandwiched between the GO layers. The nanogate formation also shows enhanced properties for various applications like photocatalytic activities, etc. Due to the nanogate formation, there might be a possibility of enormous generation of electrons on excitation of the composite materials, which can be a boom for various applications like photocatalysis, water splitting, solar cell, etc.

}, issn = {2045-2322}, doi = {10.1038/s41598-018-37396-8}, author = {Kumar, Praveen and Luwang, Meitram Niraj} } @article {47767, title = {CdS cubane type clusters encapsulated by rolling of single layer reduced graphene oxide sheets for enhanced mechanical energy harvesting}, journal = {Materials Science and Engineering B-Advanced Functional Solid-State Materials}, volume = {276}, year = {2022}, month = {FEB}, pages = {115528}, type = {Article}, abstract = {Composites with Single Layer Graphene Oxide (SLGO) sheets are extremely difficult to achieve, irrespective of the current advancements in graphene composites research. The difficulties in exfoliating the graphite oxide (GO) was associated with a strong interaction among the edge sides of the adjacent layers. This in-turn barricades the foreign intruders to interact with the basal plane, thereby restraining one to form composites with SLGO sheets. In this work, we had successfully exfoliated GO through a spacer [Cd(OAc)(2) + polyethylene glycol (PEG)] to result in nano-engineered CdS cubane-type clusters in rolled up SLGO to form graphene oxide complex compound (GOCC), resembling carbon nanotubes (CNTs). The CdS cubane-type clusters were found to interacting with the carbon skeleton of rolled reduced SLGO sheet through a Manogate{\textquoteright} structures, which was supported by density functional theory (DFT) calculations. Our theoretical study reveals that the obtained complex compound (GOCC) is thermodynamically more favourable than its ancestor materials (CdS cubane and empty CNT). Flexible piezoelectric nanogenerators (PENGs) fabricated from GOCC and thermoplastic polyurethane (TPU) resulted in output voltage (V-oc) of 4.5 V and output current of 0.4 mu A at applied force of 13 N. The nanoengineering helps to achieve superior mechanical energy harvesting performance for GOCC compared to pristine CdS, which demonstrate the potential of nanogate structures to enhance the intrinsic properties of materials.}, keywords = {Graphene oxide complex compound, Nanogate structure, New material, Novel procedure, Piezoelectric nanogenerator, SLGO}, issn = {0921-5107}, doi = {10.1016/j.mseb.2021.115528}, author = {Kumar, Praveen and Ram, Farsa and Shanmuganathan, Kadhiravan and Luwang, Meitram Niraj} } @article {48380, title = {Sulfur functionalization via epoxide ring opening on a reduced graphene oxide surface to form metal (II) Organo-bis-[1,2]-oxathiin}, journal = {Inorganic Chemistry}, volume = {61}, year = {2022}, month = {JAN}, pages = {279-286}, type = {Article}, abstract = {

The epoxide ring-opening reaction in graphene oxide (GO) by nucleophiles is a very fascinating and advanced methodology to develop novel functional material. Herewith, we report an advanced strategy for opening the epoxide ring on the rGO surface via easily an available nucleophile (Na2S), which is further functionalized with O atom to obtain four-membered rings (FMRs). The Cd coordination with the S atom puts extra stress on the FMR leading to the C-C bond cleavage of the four-membered heteroatomic rings on the rGO surface. This strategic approach leads to the fabrication of an innovative metal organo-bis-[1,2]-oxathiin (MOBOT) chemical moiety (M = Cd, Zn). The MOBOT compound further shows enhanced H-2 generation activity and hence is promising as a potential photocatalyst for solar hydrogen generation. This compound might also be a potential candidate for optoelectronic applications.

}, issn = {0020-1669}, doi = {10.1021/acs.inorgchem.1c02819}, author = {Kumar, Praveen and Bajpai, Himanshu and Gopinath, Chinnakonda S. and Luwang, Meitram Niraj} } @article {48441, title = {Cadmium (II) Organo Tetrakis-[1,2]-Oxathiin (CdOTOT): a 3D sandwiched frameworks with efficient hydrogen production}, journal = {Journal of Catalysis}, volume = {417}, year = {2023}, month = {JAN}, pages = {341-350}, type = {Article}, abstract = {

For over a decade, the structure, reactivity, and mechanism of graphene based photocatalysts have been of great interest for hydrogen (H2) generation. Several studies have been done on the edge side groups (ESGs) of graphene oxide (GO), but the basal plane groups (BPGs)-epoxide and hydroxide have acquired far less attention. This is because the GO layers are strongly held with van der waals forces as well as H-bonding which prevents the foreign body from entering inside the layers. To overcome these problems, this study presents the successful synthesis and application of four coordinated sandwiched (FCS) Cadmium (II) Organo Tetrakis-[1,2]-Oxathiin (CdOTOT) in rGO-CdS composite (A 3D sandwiched frame-work). Additionally, experimental outcomes have been further supported using density functional theory (DFT), which suggest that CdOTOT is more stable than its precursors as well as thermodynamically favourable. The CdOTOT shows high H2 production activity -67.5 mmol/g or 13.5 mmol/g/h in presence of 1 \% Pt cocatalyst and sacrificial reagents (Na2S/Na2SO3). It is around 33 times higher than pristine CdS, and stable up to around 15 hrs without adding any cocatalyst. This mesmerising outcome is over with reported various CdS-rGO based photocatalysts. The higher activity was further explained through the proposed mechanism and observed low electronic work function of CdOTOT. This innovative and extend-able (with other metals) approach provides a revolutionary impact on numerous cutting-edge research applications like photocatalysis, water splitting, solar cell, etc.(c) 2022 Elsevier Inc. All rights reserved.

}, keywords = {2], 3D sandwiched frameworks, Basal Plane Groups (BPGs), Cadmium (II) Organo Tetrakis-[1, hydrogen production, Oxathiin (CdOTOT)}, issn = {0021-9517}, doi = {10.1016/j.jcat.2022.12.019}, author = {Kumar, Praveen and Bajpai, Himanshu and Luwang, Meitram Niraj} } @article {50048, title = {Liquid crystalline nanoconfined growth of PANI on rGO for enhanced electrochemical glucose sensing}, journal = {Nanoscale}, volume = {18}, year = {2026}, month = {MAR }, pages = {5531-5543}, type = {Article}, abstract = {

We report here a new strategy for the successful synthesis of a hybrid 2D nanocomposite via the in situ functionalization of graphene oxide (GO) with aniline monomers in a bi-solvent swollen liquid crystalline lamellar mesophase (SLCLM) nanoreactor. The synthesized nanocomposite product revealed possible simultaneous reactions at the edge and basal plane of GO. A mechanism for the transformation via simultaneous nucleophilic attack and spontaneous polymerization, forming a reduced graphene oxide-polyaniline (rGO-PANI) nanocomposite, is proposed. The multistep plausible reaction mechanism for the functionalization of the GO edge -COOH group is achieved by successful synthesis, followed by isolation and characterization of the N-phenyl anthranilic acid derivative as an intermediate product. Furthermore, the detection of CO2 evolution as a by-product during the reaction complements the plausible mechanism for the incorporation of (-C Xi C-) graphyne-type edges and formation of new -C-N- and O-H bonds in the rGO-PANI nanocomposite. These results are supported by FT-IR, Raman, XPS, SAXS, and C-13 NMR spectroscopy analyses. A reduced graphene oxide-polyaniline (rGO-PANI) modified glassy carbon electrode was developed for glucose sensing, exhibiting a wide linear range (0.554-10 \& micro;M), low detection limit (50 pM), and high sensitivity (372 660 \& micro;A mM(-1) cm(-2)). The sensor demonstrated excellent selectivity against common interferents (ascorbic acid, uric acid, and dopamine), reproducibility (RSD \< 5\%), and stability over 10 000 s with minimal signal loss. The detection of glucose from human metabolites, such as urine and sweat, achieved 98-100\% recoveries for spiked glucose, confirming its practical applicability. These results establish rGO-PANI as a robust platform for sensitive and selective glucose detection.

}, issn = {2040-3364}, doi = {10.1039/d6nr00065g}, author = {Tawade, Anita K. and Kumar, Praveen and Tayade, Shivaji N. and Sharma, Geetarani K. and Luwang, Meitram Niraj and Sharma, Kiran Kumar K.} }