Synthesis and characterization of Ag doped ZnS quantum dots for enhanced photocatalysis of Strychnine asa poison: Charge transfer behavior study by electrochemical impedance and time-resolved photoluminescence spectroscopy.

In this study, the photocatalytic degradation of Strychnine was investigated by ZnS quantum dots and doped with silver in UV systems. ZnS and Ag-ZnS quantum dots were synthesized by chemical method and characterized by powder X-ray diffraction, transmission electron microscopy, UV-vis spectra and photoluminescence. The charge transfer process on the semicon-ductor/electrolyte interface was investigated via electrochemical impedance spectroscopy (EIS) and time-resolved photoluminescence. The average diameters of ZnS and Ag doped ZnS QDs were 3.0-5.0nm and 3.0-5.3nm, respectively. The band gap of ZnS and Ag-ZnS QDs was computed as 3.47 and 3.1eV, respectively. The surface area values of ZnS and Ag-ZnS QDs have been found as 78.25 and 89.54m2/g, respectively. The influences of key operating parameters such as initial pH, catalyst dosage, UV radiation intensity, reaction time as well as the effect of initial Strychnine concentration on mineralization extents were studied. The results of the study showed that the maximum removal efficiency of Strychnine had been achieved by un-doped and Ag-doped ZnS QDs at radiation intensity of 100W/m2, at time of 60min, pH of 3 and initial Strychnine concentration of 20mg/ml. Also the observations clearly showed that the photocatalysis process with Ag doped ZnS QDs are more effective than un-doped ZnS QDs.

Microwave-assisted photocatalysis of neurotoxin compounds using metal oxides quantum dots/nanosheets composites: Photocorrosion inhibition, reusability and antibacterial activity studies.

Water pollution caused by different pollutants is one of the challenging tasks for the scientific community. We have prepared and characterized a material for removal of pollutant compounds. ZnO quantum dots decorated CuO nanosheets and TiO2 quantum dots decorated WO3 nanosheets composites have been prepared using a hydrothermal method. The as synthesized catalysts were characterized by various techniques. The crystallite sizes of CuO NSs and WO3 NSs were to be obtained 12.5 and 13.25nm and when dopped with ZnO and TiO2 size reduces to 3.2 and 3.9nm, respectively. The energy band gap of the CuO NSs, WO3 NSs, ZnO QDs/CuO NSs and TiO2 QDs/WO3 NSs composite are calculated to be 2.01, 2.61, 1.86 and 2.32eV, respectively. The prepared catalysts are efficiently utilized for the photocatalytic degradation of two neurotoxin compounds under UV and UV coupled with microwave irradiation. The prepared catalyst composites reveal excellent photocatalytic degradation of neurotoxin compound by degrading it up to 75% under UV and UV/microwave irradiation. The photocalysis efficiency in UV/microwave system is higher than UV system. The result shows that the ZnO QDs/CuO NSs and TiO2 QDs/WO3 NSs composites have excellent photocorrosion inhibition and reusability properties. Thus, prepared samples with positive surface potential upon interaction with negative surface potential of Enterococcus faecalis and Micrococcus luteus.

Synthesis of CdSe quantum dots decorated SnO2 nanotubes as anode for photo-assisted electrochemical degradation of hydrochlorothiazide: Kinetic process.

Pharmaceutical residues have been increasingly detected in the aquatic environment and are considered important contaminants of emerging concern. This study examines the photo assisted electrochemical degradation of the Hydrochlorothiazide by using CdSe quantum dots decorated SnO2 nanotubes. The characteristic devices such as Scanning electron microscopy, X-ray diffraction, UV-vis diffuse reflectance Transmission electron Microscopy were used to analyze information structure of CdSe QDs/SnO2 nanotubes. All the experiments were perform with influence of the current density (10-60mAcm-2) and sodium chloride (0.02-0.10molL-1) in the supporting electrolyte composition was analyzed. The results showed that the Hydrochlorothiazide and TOC removal was achieved in the current density range used. As expected, the degradation kinetics presented a pseudo first order behavior. Comparison of the efficiencies of the photocatalytic, electrochemical (EC) and photo-assisted electrochemical (PAEC) techniques verified that the combined process showed a synergism for HCT and TOC removal.

Synthesis and characterization of Ag2S decorated chitosan nanocomposites and chitosan nanofibers for removal of lincosamides antibiotic.

We report the synthesis of Ag2S-Chitosan nanocomposites and Ag2S-chitosan nanohybrids as performance adsorbents for Lincosamides such as Clindamycin antibiotic removal. Isotherms and kinetic studies were determined to understand the adsorption behavior both two adsorbent. At low adsorbent dose, removals are increased in the adsorption process, and performance is better with Ag2S-chitosan nanohybrids due to the special surface area increased. The average sizes and surface area of Ag2S-Chitosan nanocomposites and Ag2S-chitosan nanohybrids were found as 50nm, 70nm and 180.18, 238.24m2g-1, respectively. In particular, Ag2S-Chitosan nanocomposites and Ag2S-chitosan nanohybrids show high maximum Clindamycin adsorption capacity (qmax) of 153.21, and 181.28mgg-1, respectively. More strikingly, Ag2S-Chitosan nanocomposites and Ag2S-chitosan nanohybrids are also demonstrated to nearly completely remove Clindamycin from drinking water. The excellent adsorption performance along with their cost effective, convenient synthesis makes this range of adsorbents highly promising for commercial applications in drinking water and wastewater treatment.