Microwave-mediated synthesis of tetragonal Mn3O4 nanostructure for supercapacitor application.

The development of electrode materials plays a vital role in energy storage applications to save and store energy. In the present work, the synthesis of nanorod shaped Mn3O4 supported with amorphous carbon (Mn3O4/AC) is reported by the microwave method for supercapacitor application. The as-prepared electrode material was then characterized using microscopic and spectroscopic techniques. The electrochemical supercapacitor performance of Mn3O4/AC was examined by the cyclic voltammetry and galvanostatic charge-discharge method inside the three-electrode assembly cell. The results showed that the Mn3O4/AC delivers the excellent capacitance value of the 569.5 Fg-1 at the current load of 1 Ag-1, higher than the previously reported Mn3O4 based electrodes. The better performance of the Mn3O4/AC is credited to the excellent redox behaviour of the Mn3O4 and the presence of the amorphous carbon, which facilitated the fast ion interaction between the electrode and electrolyte during the electrochemical reaction.

Combined effect of ZnO nanoripples and solvent additive on the nanomorphology and performance of PTB7-Th: PC71BM organic solar cells.

In bulk heterojunction organic solar cells (OSCs), nanomorphology of the photoactive layer plays a crucial role in determining photocurrent and fill factor (FF) of OSCs, and therefore it is essential to control the nanomorphology of the photoactive layer to fabricate devices with high power conversion efficiency (PCE). We demonstrate the combined effects of a ZnO nanorippled electron transport layer (ETL) and solvent additive (1,8-diiodooctane (DIO)) on the nanomorphology and performance of a model OSC in an inverted geometry. The photoactive layer in the model OSC is composed of Poly [4,8-bis (5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl] (PTB7-Th):phenyl-C71-butyric acid methyl ester (PC71BM) blend. It is observed that the use of ZnO nanoripples as an ETL and DIO as a solvent additive facilitates the formation of near ideal nanomorphology of bi-continuous interpenetrating network of donor and acceptor. This is confirmed by morphological studies using atomic force microscopy, scanning electron microscopy and transmission electron microscopy. Photo-electrochemical impedance spectroscopy measurements confirm that obtained nanomorphology of bicontinuous interpenetrating network is contributing to the improved device performance. The device with 3 vol% DIO, with underneath ZnO nanoripples exhibited improved current density (J sc), FF, open circuit voltage (V oc) and PCE of 15.57 mA cm-2, 64.50%, 0.81V and 8.20%, respectively.

Synthesis and characterization of structural, optical, thermal and dielectric properties of polyaniline/CoFe2O4 nanocomposites with special reference to photocatalytic activity.

In this study we have synthesized polyaniline/CoFe2O4 nanocomposites (PANI@CFs) by in situ polymerization method with different amounts of the CoFe2O4 nanoparticles NPs (CF-NPs) (0.5 g and 1.0 g). The structural optical, thermal and dielectric properties of the as synthesized PANI@CFs were studied. The XRD analysis ensures that CF-NPs have a single phase spinel structure. The XRD and EDAX results confirmed that the CF-NPs were successfully incorporated in the PANI matrix. The crystalline size analysis revealed that the size increased with increasing CF-NPs amount in the PANI@CFs, because of the aggregation effect. TGA exhibited an enhanced thermal stability of the PANI@CFs as compare with PANI owing to the strong interaction between the CF-NPs and polymer matrix. The energy band gaps as calculated through the Tauc relation were found to be gradually higher with the increasing the amount of CF-NPs in PANI@CFs. The dielectric constants (ε', ε″), dielectric loss (tanδ) and AC conductivity (σac) were studied as the function of frequency and composition, which have been explained by 'Maxwell Wagner Model'. The high dielectric constant and ac conductivity were observed of PANI@CFs than PANI. Moreover, PANI@CF 1:2 exhibited the promising photocatalytic activity for the photo-decoloration of the methyl orange (MO) dye under UV light irradiation. Results also showed protection of photo-decoloration of the MO dye by the disodium ethylenediaminetetraacetate dehydrate (EDTA-Na2; C10H14N2Na2O8·2H2O) (hole scavenger) and tert-butyl alcohol (C4H10O) (radical scavenger) clearly suggested the implication of reactive oxygen species (ROS) in the photocatalytic activity of PANI@CF 1:2. It is encouraging to conclude that PANI@CF bears the potential of its applications in photocatalysis.