Waseem Raza

Development of PANI/MWCNTs decorated with cobalt oxide nanoparticles towards multiple electrochemical, photocatalytic and biomedical application sites

In the present work, a ternary nanocomposite of Co3O4doped/PANI/MWCNTs (cobalt oxide-doped polyaniline multi-walled carbon nanotubes) was synthesized via the in situ oxidative polymerization of aniline. The composite was fully characterized using instrumental analysis, and further tested for its potential in electrochemical, photocatalytic and biomedical applications. The Co oxide nanoparticles were first synthesized using the sol–gel approach in the presence of starch as a capping agent so as to prevent agglomeration and characterized using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), EDX, elemental mapping and high-resolution transmission electron microscopy (HRTEM). For the measurement of electrochemical activity, the electrodes were synthesized with MWCNTs and functionalized with a conducting polymer (PANI). For the composite, the Co metal oxide provides a pseudo-capacitance which, in general, improves the performance characteristics of the electrode and has been the focus of many researchers. Further, the specific capacitance of the prepared composite was tested using cyclic voltammetry (CV) and impedance spectroscopy. The capacitive studies reveal that the composite has a synergistic effect and is observed to have the highest specific capacitance of 382 F g−1 run at a scan rate of 10 mV s−1. The composite was also found to have excellent photocatalytic degradation properties and outstanding antibacterial activity against both Gram positive and Gram negative bacterial strains. The minimum MIC (6.25 μg mL−1) and MBC (12.5 μg mL−1) values against E. coli and maximum values against B. amyloliquefaciens (25 and 50 μg mL−1) at fourth dilution were observed. Furthermore, the anticancer efficiency of the composite was tested by making use of two different cancer cell types (MCF-7 and MDA-MB-231) confirming the importance of its biological activity for biomedical applications.

Preparation, Characterization and Application of Polyaniline/silk Fibroin Composite

We report the electrical properties and photocatalytic activity of polyaniline (Pani) and polyaniline/silk fibroin (Pani/SF) composite. The Pani/SF composite has been synthesized first time by chemical oxidative in-situ polymerization method by using potassium persulphate (K2S2O8) in an acidic medium. Thus prepared Pani and Pani/SF composite were characterized by using Fourier-transform infrared spectroscopy, x-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The stability in terms of the DC electrical conductivity of Pani/SF composite and Pani was investigated under isothermal and cyclic aging conditions. Results indicated that the electrical properties of the composite were significantly influenced by the loading of SF to Pani and observed to be more thermally stable than those of Pani. As-prepared Pani and Pani/SF composites were studied for the degradation of methylene blue (MB) and Rhodamine B (RhB) under UV-light irradiations. The results showed that 91.4% & 85.4% degradation of RhB and MB takes place respectively after 90 min over Pani/SF composite. The decomposition rate of composite was 1.8-2.2 times greater than that of Pani. The improvement of photocatalytic activity of composite may be attributed to the electron-sink function of silk fibroin which increases the optical absorption property and separation of photogenerated charge carriers than Pani alone.

Engineering Defects in Graphene Oxide for Selective Ammonia and Enzyme-Free Glucose Sensing and Excellent Catalytic Performance for para-Nitrophenol Reduction

Recently, extensive attention has been given to developing an active and durable metal-free economical sensor and catalyst. Graphene oxide (GO)-based sensors and catalysts have been considered as a promising candidate in current material science research. However, the sensing and catalytic properties of GO also need to be further improved to satisfy the specific applications, such as gas detection in harsh environments, medical diagnosis based on human breath, blood glucose detection, catalytic activity, and so forth. Therefore, the effect of nitrogen in GO on the performance of glucose and ammonia sensing, and catalytic activity has been investigated. Herein, we propose a practical, high-sensitive sensor and catalyst based on high-quality defect N-enriched GO. One-step, low-cost solvothermal synthesis of N-enriched GO has been exploited for the development of high-performance sensors and excellent catalyst at room temperature. The resultant N-enriched GO (N8GO) has been studied as a promising sensing material for ammonia, glucose, and para-nitrophenol (PNP) reduction. The prevalent outstanding sensing and catalytic performance may be due to the synergistic effect of nitrogen. A probable mechanism for sensing and catalytic reduction of PNP using N8GO has been proposed.

() and ()-1,4-Diphenyl-2-(2-phenyl-1-benzo[]imidazol-1-yl)but-2-ene-1,4-dione

The title compound C29H20N2O2 adopts and geometry about olefinic C14–C22 bond, where the benzoyl group at C22 and benzimidazole group at C14 lie on the opposite sides and on the same side across the olefinic bond, respectively. In configuration the phenyl groups of both benzoyl moieties are almost perpendicular to benzimidazole ring while the phenyl of benzimidazole at C7 is oriented at an angle of 30.76 (5)° to the mean plane of the benzimidazole ring. On the other hand in configuration the phenyl group at C7 of benzimidazole ring is oriented at an angle of 38.44 (7)° to the mean plane of the benzimidazole ring while the phenyl rings of benzoyl moieties at C15 and C23 lie at an angle of 16.07 (9)° and 40.29 (6)°, respectively, to the mean plane of the benzimidazole ring. The observed bond distances and bond angles fall within the normal accepted range of values.