In this work, removal of fluorescein and eosin dyes using common agrowaste, i.e., peels of water melon (Citrullus lanatus) (WMP), has been studied in the batch mode. e sorbent material (WMP) was characterized by using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. e sorbent was chemically modified by subjecting it to 0.1 N HNO 3 and 0.1 N NaOH solutions. Different parameters such as sorbent dose, pH, temperature, and agitation speed were optimized to investigate the sorbent efficiency for fluorescein and eosin dyes. Among three forms (raw, base-treated, and acid-treated), the base-treated form exhibited higher removal efficiency, followed by acid-treated and then the raw form. Generally, range for the removal of fluorescein and eosin was found to be 48.06-88.08% and 48.47-79.31%, respectively. Mathematical modeling of sorption data by Langmuir and Freundlich sorption isotherms and thermodynamic investigations were carried out to check the suitability of these agrowaste materials on bulk scale. e promising results concluded that peel of water melon (common agrowaste) can be potentially utilized for the removal of toxins.

Three new lead based organic frameworks, [Pb(C6H6O2S2N)2] (1), [Pb(C12H6O4).(H2O)]n (2), [Pb(C14H8O4)]n (3) have been synthesized via hydro/solvothermally using 2‐mercapto‐3‐methyl‐4‐thiazoleacetic acid (H2MMTA), 2,6‐naphthalenedicarboxylic acid (2,6‐NDA) and biphenyl‐4,4′‐dicarboxylic acid (H2BDA) as organic precursors. The resulting metal organic frameworks (MOFs) were characterized by UV/Vis, Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), 1H NMR, Energy dispersive spectroscopy (EDS), Thermogravimetric analysis (TGA) and Powder X‐ray diffraction technique. MOF (1) has also been characterized by single‐crystal X‐ray diffraction method which exhibited a three‐dimensional (3D) framework with an octahedral hemidirected environment around each Pb2+ ion. All these MOFs (1 − 3) were screened for their luminescence activity. This luminescence activity has been assigned to metal‐centred s→p transition in case of MOF (1) and ligand‐to‐metal charge transfer (LMCT) in case of MOFs (2 & 3). Adsorption of N2 gas by these MOFs was investigated and the results of this study are also part of this manuscript.

Layered structured Ca 3 Co 4 O 9 has displayed great potential for thermoelectric (TE) renewable energy applications, as it is nontoxic and contains abundantly available constituent elements. In this work, we study the crystal structure and high-temperature TE properties of Ca 3–2 y Na 2 y Co 4– y Mo y O 9 (0 ≤ y ≤ 0.10) polycrystalline materials. Powder X-ray diffraction (XRD) analysis shows that all samples are single-phase samples and without any noticeable amount of the secondary phase. X-ray photoelectron spectroscopic (XPS) measurements depict the presence of a mixture of Co 3+ and Co 4+ valence states in these materials. The Seebeck coefficient ( S ) of dual-doped materials is significantly enhanced, and electrical resistivities (ρ) and thermal conductivities (κ) are decreased compared to the pristine compound. The maximum thermoelectric power factor (PF = S 2 /ρ) and dimensionless figure of merit ( zT ) obtained for the y = 0.025 sample at 1000 K temperature are ∼3.2 × 10 –4 W m –1 K –2 and 0.27, respectively. The zT value for Ca 2.95 Na 0.05 Co 3.975 Mo 0.025 O 9 is about 2.5 times higher than that of the parent Ca 3 Co 4 O 9 compound. These results demonstrate that dual doping of Na and Mo cations is a promising strategy for improving the high-temperature thermoelectric properties of Ca 3 Co 4 O 9 .

The condensation reactions of biacetyl with ortho-hydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML 2 (H 2 O) 2 ] where M = Co(II), Ni(II), Cu(II) and Zn(II) and L = HL 1 and HL 2 . These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1 H-NMR, 13 C-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141-160 °C. These compounds were also screened for their in vitro antibacterial activity against four bacterial species, namely: Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtilis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.

At the ultrathin scale, nanomaterials exhibit interesting chemical and physical properties, like flexibility, and polymer-like rheology.