Optimized, simple and selective analytical tool for determination of carcinogenic aniline in wastewater.

Here, we explored a low-cost, rapid, sensitive, and selective practical approach to manifest carcinogenic anilines by using oxone as an oxidant to mitigate its presence in wastewater. The calibration curves for OAP & PAP indicate reasonable sensitivity, percent recovery & correlation in the range 2.18-9.28 µg/mL. The Sandell's sensitivity for OAP & PAP was found to be 0.010-0.018 & 0.009-0.018 µg/mL, respectively. The range of correlation coefficient 0.979 to 0.998 shows the involvement of high precision and perfect correlation of the data. Values of coefficient of determination (r2) denote the change in absorbance or (dA/dt)i or kobs by 95.8-99.6%. The percent recovery was found to be 98.05-99.91% for six parallel determinations. Furthermore, we also analyzed some wastewater samples to further validate the proposed method. The reproducible results, good percent recovery, and reasonable sensitivity proposed a feasible approach for the estimation of aminophenol in wastewater.

RGO supported ZnO/SnO2 Z-scheme heterojunctions with enriched ROS production towards enhanced photocatalytic mineralization of phenolic compounds and antibiotics at low temperature.

In the present study, the excellent photocatalytic activity of n-ZnO/n-SnO2 heterojunction integrated with reduced graphene oxide nanosheets was explored towards the elimination of different organic pollutants viz. p-bromophenol, bisphenol A, and ofloxacin from water. n-ZnO/n-SnO2 heterojunction was decorated with a different weight percentage of reduced graphene oxide via a facile refluxing method. The structural, morphological and optical properties of the as-prepared n-ZnO/n-SnO2 heterojunction-reduced graphene oxide nanocomposites were investigated systematically. XRD, Raman and FT-IR confirmed the hexagonal wurtzite and tetragonal rutile structures of ZnO and SnO2 crystals in different nanocomposites. Cube and spherical-shaped surface structures were demonstrated by TEM and FE-SEM analysis for ZnO and SnO2, respectively. The maximum photocatalytic productivity of nanocomposite with 5 wt% reduced graphene oxide was observed at about 98.64 % and 98.50 % towards the elimination of p-bromophenol and bisphenol A, respectively after 180 min exposure of UV light. Similarly, this productivity was also observed at about 99.13 % towards the elimination of ofloxacin after 120 min irradiation of UV light. The outstanding photocatalytic activity of nanocomposite with 5 wt% reduced graphene oxide has been proven by the presence of homotypic n-ZnO/n-SnO2 and reduced graphene oxide nanosheets owing to the synergistic effect amongst them resulting in remarkable separation of charge carriers, which is responsible for the larger rate of reactive oxygen species generation and enhanced photodegradation of p-bromophenol, bisphenol A and ofloxacin. In this study, the results illustrated that the photocatalytic degradation of p-bromophenol, bisphenol A and ofloxacin using n-ZnO/n-SnO2 heterojunction-reduced graphene oxide nanocomposites is predominantly based on the hydroxyl radicals and superoxide radical anion as main reactive oxygen species as compared to 1O2. A reasonable photodegradation mechanism using prepared nanocomposites under investigation has also been proposed.

ZnO-CdO nanocomposites incorporated with graphene oxide nanosheets for efficient photocatalytic degradation of bisphenol A, thymol blue and ciprofloxacin.

The widespread existence of different organic contaminants mostly phenolic compounds, organic dyes and antibiotics in water bodies initiated by the various industrial wastes that raised great scientific concern and public awareness as well recently owing to their prospective capability to spread these contaminants resistant gene and pose hazard to human. In the present study, a series of nanostructured ZnO-CdO incorporated with reduced graphene oxide (ZCG nanocomposites) were successfully synthesized by a simple refluxing method and characterized by using the X-ray diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, photoluminescence spectroscopy, field emission-scanning microscope (FE-SEM) and UV-visible diffused reflectance spectroscopy (DRS) for the photocatalytic degradation of bisphenol A (BPA), thymol blue (ThB) and ciprofloxacin (CFn) with illumination of UV light. The maximum degradation and mineralization of BPA, ThB and CFn was achieved around 98.5%, 98.38% and 99.28% over the ZCG-5 nanocomposite photocatalyst after UV light irradiation for 180 min, 120 min and 75 min, respectively. The superior photocatalytic activity of ZCG-5 ascribed to enhance adsorption capacity, effective separation of charge carriers consequential for the production of more ROS after incorporation of RGO nanosheets with ZnO-CdO in photocatalyst. The conceivable photocatalytic degradation mechanism of BPA, ThB and CFn was elucidated through ROS identification and the assessment of photocatalyst stability by reusability, EEO (kwh/m3order) and UV light dose (mJ/cm2) were evaluated. The plausible photocatalytic degradation pathways were proposed for the degradation of BPA, ThB and CFn via GC-MS analysis. The present work investigates the efficient removal of BPA, ThB and CFn using ZCG nanocomposites as photocatalyst.

rGO-ZnO nanocomposites as efficient photocatalyst for degradation of 4-BP and DEP using high temperature refluxing method in in-situ condition.

Persistent organic pollutants (mainly aromatic compounds) such as bromophenol and diethyl phthalate are dangerous and act as primary contaminants in aqueous system. In this study, efficient reduced graphene oxide zinc oxide (rGO-ZnO) nanocomposites were synthesized by using a simple and facile method for photocatalytic degradation of 4-Bromophenol (4-BP) and diethyl phthalate (DEP). The rGO-ZnO (rGZ) nanocomposites (NCs) with different weight ratio of rGO and ZnO (coded as rGZ-1, rGZ-2, rGZ-5 and rGZ-10) were synthesized via high temperature refluxing method. The crystalline structure and phase, surface morphological study, optical properties, crystal defects and existence of functional groups in rGZ NCs were studied by X-ray diffraction (XRD), field-emission-scanning electron microscope (FE-SEM), UV-Visible diffuse reflectance spectroscopy (DRS), Raman spectroscopy and FT-IR analysis, respectively. The elimination of 4-BP and DEP from water by UV-light exposure was considered to estimate the photocatalytic efficiency of prepared rGZ NCs. The maximum elimination of 4-BP and DEP via photodegradation (advanced oxidation process) was found about 99.04% and 98.63% over rGZ NCs after 180 min UV irradiation, respectively. The photodegradation study was examined by using high performance liquid chromatography (HPLC) technique. This study confirms the efficient photocatalytic activity of rGZ-5 towards degradation of 4-BP and DEP. Finally, degradation mechanism has been proposed for the degradation of 4-BP and DEP.

Optimization and computational studies evaluating molecular dynamics of EDA cored polymeric dendrimer.

In this work we report the results acquired from molecular dynamics simulations as well as the optimization of different generations of polyamidoamine dendrimer. The analysis data revealed synthesized dendrimer as a suitable nanostructured candidate suitable for neutral as well as charged molecule delivery due to the presence of both electrostatic potential and van der Waals forces. The methyl ester terminating groups of half-generation dendrimers with characteristic IR peaks for carbonyl at 1670.41 cm-1 tends to shift to 1514.17 cm-1 on conversion to amide group of full-generation dendrimer. The study includes the usage of detailed analysis, demonstrating how molecular dynamics affect the dendrimer complexation. The present investigations provide an unprecedented insight into the computational and experimental system that may be of general significance for the clinical application of dendrimers.