Neutral tetradentate N 2 O 2 type complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been synthesised using the Schiff base formed by the condensation of acetylacetone and p-anisidine. Microanalysis, molar conductance, magnetic susceptibility, IR, UV-Vis, 1 H NMR, CV and EPR studies have been carried out to determine the structure of the complexes. From the data, it is found that all the complexes possess square-planar geometry. The EPR spectrum of the copper complex in DMSO at 300 K and 77 K was recorded and its salient features are reported. All the title complexes were screened for antimicrobial activity by the well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values were calculated at 37°C for a period of 24 h. It has been found that all the complexes are antimicrobially active and show higher activity than the free ligand.

In this present work, "killing two birds with one stone" strategy was performed for the electrochemical trace level detection and photocatalytic degradation of antibiotic drug chloramphenicol (CAP) using Ce(MoO) nanocubes/graphene oxide (CeM/GO) composite for the first time. The CeM/GO composite was synthesized via simple hydrothermal treatment followed by sonication process. The successful formation of CeM/GO composite was confirmed by several analytical and spectroscopic techniques. The CeM/GO composite modified glassy carbon electrode (GCE) showed excellent electrocatalytic activity toward the reduction of CAP in terms of decrease the potential and increase the cathodic peak current in comparison with different modified and unmodified electrodes. The electrocatalytic reduction of CAP based on the CeM/GO modified GCE exhibited high selectivity, wide linear ranges, lower detection limit, and good sensitivity of 0.012-20 and 26-272 μM, 2 nM ,and 1.8085 μA μM cm, respectively. Besides, when CeM/GO/GCE was used to analyze the CAP in real samples, such as honey and milk, the satisfactory recovery results were obtained. On the other hand, the CeM/GO composite played excellent catalyst toward the photodegradation of CAP. The obtained results from the UV-vis spectroscopy clearly suggested that CeM/GO composite had high photocatalytic activity compared to pristine Ce(MoO4) nanocubes. The degradation efficiency of CeM/GO toward CAP is observed about 99% within 50 min under visible irradiation and it shows a good stability by observing the reusability of the catalyst. The enhanced photocatalytic performance was attributed to the increased migration efficiency of photoinduced electrons and holes.

In the present work, potato-like silver molybdate (Ag2MoO4) microstructures were synthesized through a simple hydrothermal method. The microstructures of Ag2MoO4 were characterized by various analytical and spectroscopic techniques such as XRD, FTIR, Raman, SEM, EDX and XPS. Interestingly, the as-prepared Ag2MoO4 showed excellent photocatalytic and electrocatalytic activity for the degradation of ciprofloxacin (CIP) and electrochemical detection of hydrogen peroxide (H2O2), respectively. The ultraviolet-visible (UV-Vis) spectroscopy results revealed that the potato-like Ag2MoO4 microstructures could offer a high photocatalytic activity towards the degradation of CIP under UV-light illumination, leads to rapid degradation within 40 min with a degradation rate of above 98%. In addition, the cyclic voltammetry (CV) and amperometry studies were realized that the electrochemical performance of Ag2MoO4 modified electrode toward H2O2 detection. Our H2O2 sensor shows a wide linear range and lower detection limit of 0.04–240 μM and 0.03 μM, respectively. The Ag2MoO4 modified electrode exhibits a high selectivity towards the detection of H2O2 in the presence of different biological interferences. These results suggested that the development of potato-like Ag2MoO4 microstructure could be an efficient photocatalyst as well as electrocatalyst in the potential application of environmental, biomedical and pharmaceutical samples.

No abstract

Material combinations of semiconductor with conducting polymer are gaining growing interest due to their enhanced activities in photocatalysis as well as electrochemical sensing. In this present work, we report a facile in situ synthesis of polypyrrole (PPy) polymer-incorporated silver molybdate (Ag 2 MoO 4 ) nanocomposite that is utilized as a photocatalyst and electrocatalyst for the degradation of pollutant heavy metals, namely, methylene blue (MB) and heavy metal (Cr(VI)), and ciprofloxacin (CIP) and for detection of the drug, azomycin. The synthesized nanocomposite was characterized by various theoretical, spectral, and microscopic studies. Matching of the powder X-ray diffraction pattern with JCPDS no. 76-1747 confirmed the formation of α-Ag 2 MoO 4 /PPy. The surface topography and spherical morphology of the nanocomposite were studied using field emission-scanning electron microscopy and transmission electron microscopy. Fourier transform infrared spectral detail expounds the smooth incorporation of PPy to Ag 2 MoO 4 . The as-synthesized nanocomposite performs as an efficient photocatalyst in the degradation of MB (99.9%), Cr(VI) (99%), and CIP drug (99.8%) within 10 min. In addition to this, the Ag 2 MoO 4 /PPy-modified glassy carbon electrode (GCE) demonstrated excellent electrocatalytic activity in terms of a higher cathodic peak current and lower peak potential when compared with other modified and unmodified GCEs for the detection of azomycin. The Ag 2 MoO 4 /PPy/GCE displayed a broader linear response range and lower detection limit of 0.5−499 μM and 65 nM, respectively. Moreover, other potentially co-interfering compounds, such as a similar functional group-containing biological substances and inorganic species, have no interference effect toward azomycin sensing.