Search

Water pollution is one of the major global challenges today. Water bodies are contaminated by the heavy release of waste effluents of textile industries, which includes intensively colored dye pollutants. Herein, a ternary nanocomposite of bismuth copper selenide with small particle size and ternary metal selenide (TMS)‐chitosan microspheres (TMS‐CM) of the spherical porous surface were successfully synthesized. SEM, XRD, EDX, FTIR, and UV/Vis spectrophotometry analysis revealed the structural and morphological characteristics of the newly synthesized nanocomposites. SEM imaging showed the average diameter of TMS nanoparticle to be 33 nm. The crystal size was calculated as 6.33 nm and crystalline structure as orthorhombic using XRD findings. EDX confirmed the presence of Bi, Cu, and Se in the ternary nanocomposite. The bandgap of 1.8 eV was calculated from Tauc's plot for the TMS nanocomposite. SEM confirmed the successful synthesis of spherical TMS‐CM microspheres of porous surface morphology with an average size of 885.6 μm. The presence of chitosan microspheres in the synthesis of TMS nanocomposite was identified by FTIR spectral analysis. Furthermore, highly efficient photocatalytic degradation (up to 95.4%) of ARS was achieved within 180 min at pH 4.0 using 0.5 g of TMS‐CM in sunlight. The first‐order kinetic model fitted well to the photocatalytic decontamination of ARS using TMS‐CM with a rate constant of 6.1x10−2 min−1. The TMS‐CM gave attractive results and high efficiency in photocatalytic degradation of ARS dye after reusing and regeneration of up to seven successive cycles. The newly synthesized nanophotocatalyst could be efficiently used for the decontamination of dye polluted water from textile industries. [ABSTRACT FROM AUTHOR]

This work is aimed at exploring the efficiency of a novel H2O2 modified activated carbon (PA-AC-HO) prepared from used tea leaves (UTLs) for the removal of toxic cationic dye, malachite green (MG) from aqueous systems. The surface properties of PA-AC-HO were analyzed by FTIR spectroscopy, scanning electron microscopy (SEM), BET surface area (SBET), Boehm's titration and point of zero charge (pHPZC), thermogravimetric (TG/DTA) and X-rays diffraction (XRD) analysis. Results showed that PA-AC-HO has sufficient number of acidic functional groups and pHPZC value lies in the acidic region. The SEM study confirmed that the adsorbent external surface is highly porous with BET surface area of 1,097.68 (m² g-1) and total pore volume of 0.83 cm3 g-1. Proximate-ultimate analysis showed high carbon and oxygen content of PA-AC-HO with amorphous nature. The adsorption characteristics of PA-AC-HO for the uptake of MG were studied by batch method. The dye uptake capacity and rate was found to increase with increasing contact time, dye initial concentrations and solution pH, but showed a decreasing trend with increasing salt ionic strength. Kinetic investigation revealed that adsorption of MG followed pseudo-second order model while the equilibrium isotherm data fitted the Langmuir and Temkin models well and maximum adsorption capacity was found to be 454.55 mg g-1. Thermodynamic investigation showed spontaneous and endothermic nature of the adsorption. Regeneration of dye loaded adsorbent was carried out by five consecutive cycles which showed good regeneration capacity. [ABSTRACT FROM AUTHOR]