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In the present work a comparative study of electrical, dielectric and EMI shielding behaviour of copper metal-PVDF and copper ferrite- PVDF composites has been carried out. The obtained results sug...

Photoelectrochemical cell composed of solution-processed nanoflower heterostructure of Au core and eight CdSe petals was investigated for enhanced photocurrent generation. The electrode of CdSe nanorods displayed photocurrent density of 2.1 mA/cm2 whereas the Au core CdSe nanoflower exhibited 4.6 mA/cm2 corresponding to a 119% increase during photoelectrochemical cell performance. Both electrodes showed prompt response to the on/off cycles of light, the photocurrent gain (IPhoton/Idark) in CdSe nanorods is 124.7, while the value is 223.3 for Au/CdSe nanoflower, calculated from the growth-decay curves. Photoresponse time was dramatically improved for Au/CdSe nanoflower samples due to increasing in 66% incident photon-to-current emission. Electron lifetime of 21.63 and 48.71 ns was observed for the electrode of CdSe nanorods and Au/CdSe nanoflowers respectively. The prolonged electron lifetime in the case of the electrode of Au/CdSe nanoflowers was responsible for improving charge separation and as a consequence, higher photocurrent generation.

Present work reports the fabrication of EMI shielding composites consisting of multi-walled carbon nanotubes (MWNTs) and graphite uniformly dispersed in an insulating polymer matrix i.e. polyvinylidene fluoride (PVDF). The EMI shielding is measured in the X-band frequency range (8–12 GHz) for all the composites. Absorption and reflection radiations are seen to be increasing with increasing the graphite and MWCNT level in the composite and a high EMI shielding effectiveness (SE) value of 14.64 dB has been achieved. The results are promising for the development of a novel, low cost, light weight, and flexible EMI shielding material.

Acrylonitrile-butadiene-styrene (ABS) composites were prepared by dry mixing equal-quantity (20 wt%) charcoals treated at different temperatures followed by hot compression. Processing parameters were kept the same. Seven samples of the same charcoal were modified for carbonization at different temperatures varying from 500 °C to 1100 °C in steps of 100 °C. Temperature treatment of charcoal crafts an increase in the conductivity of ABS composites, primarily accountable for the enhancement of shielding. The electromagnetic shielding effectiveness in the X-band (8.2–12.4 GHz) has been discovered to significantly increase for composites with ascending temperature-treated charcoals. An abrupt increase in the conductivity of ABS composites containing equal quantities of charcoal subjected to enhanced temperature treatments truly explains the effective absorption behaviour. The composite containing 1100 °C temperature-treated charcoal shows absorption-dominated SE of ∼36.8 dB at 11.6 GHz. Dielectric behaviour proclaims a decrease in dielectric loss (e′′) with an increase in the frequency. Besides this, the increased carbonization temperatures also show increased porosity and high dielectric losses. The scanning electron microscopy studies validate the increase in the porosity of charcoals due to the increase in the treatment temperature. The results are promising for the development of custom-made shielding composites possessing equal quantities of charcoal treated at enhanced temperatures.