Indrani Mukherjee

A facile approach for the synthesis of copper(II) myristate strips and their electrochemical activity towards the oxygen reduction reaction

The usage of an inexpensive and non-noble metal-based material as the electrocatalyst in the oxygen reduction reaction has gained great attention for fuel cell application. In this report, a facile approach has been developed for the synthesis of copper myristate strips. The as-synthesized material has demonstrated its electrocatalytic activity towards oxygen reduction reaction. This study opens up a new scope for the use of straight chain copper complexes as electrocatalysts. The interesting performance of the copper myristate strips holds promising application in energy conversion devices.

Two-Dimensional Nanostrips of Hydrophobic Copper Tetradecanoate for Making Self-Cleaning Glasses

We report a simple, solution-based technique for coating arbitrary surfaces with thin layers of self-assembled copper tetradecanoate CTD nanostrips, resulting in an optically transparent, superhydrophobic coating. The nanostrip-coated surfaces show water contact angles close to 150° and roll-off angles as small as 2°-3°. Importantly, CTD retains its hydrophobic nature even after annealing the self-assembled nanostrips at 200°C, which does not alter the crystal structure but “melts” the surface microstructure. This clearly indicates that the hydrophobicity in CTD is likely to be intrinsic in nature and not induced by the surface microstructure as has been suggested earlier. Strong hydrophobicity in CTD over a relatively wide temperature range presumably results from the presence of the long aliphatic tetradecanoate chains in its structure. Importantly, the self-assembled copper tetradecanoate nanostrips can be dip-coated on glass to render it hydrophobic and at the same time retain a significant level of transparency over the entire visible region. Such nanostructured thin films may be expected to find applications not only as a self-cleaning glass, but also as a corrosion resistant coating, in gas storage due to the layered structure, and as an active catalyst because of the visible absorbance.

Dissimilitude behaviour of Cu2O nano-octahedra and nano-cubes towards photo- and electrocatalytic activities

We demonstrate how the morphology of a simple metal-oxide system (e.g., Cu2O) controls catalytic activity. Cu2O catalysts were synthesized with a highly uniform nanocube and nano-octahedra morphology under PVP surfactant-assisted reaction conditions. A series of structural, morphological, optical and electrical characterizations are done to optimize the growth of nanostructures with different morphologies. Finally, the nanostructures are exploited as photo- and electrocatalysts. Interestingly, we find dissimilitude behaviour of nano-octahedra and nano-cube samples towards photo and electrocatalytic activities. The nano-octahedra samples are ∼57% more photocatalytically active (half-life timeoctahedra ∼ 10.7 minutes) than the nanocube samples, which is one of the highest reported photocatalytic efficiencies reported to date. However, the same nano-octahedra samples show lower electrocatalytic activity towards oxygen reduction reaction (ORR) as compared with the nanocube sample.

Truncated hexagonal bi-pyramidal gallium ferrite nanocrystals: integration of structural details with visible-light photo-activity and self-cleaning properties

We report the growth of gallium ferrite (GaFeO3 or GFO) nanocrystals with a unique morphology, “truncated hexagonal bi-pyramid” (THBP), and with a novel orthorhombic P212121 symmetry under hydrothermal conditions in pure water without using any reducing or shape defining reagent. The growth conditions of such a structure are optimized through a detailed study using field emission scanning electron microscopy. The structural details of the above hitherto unreported phase of the material are studied using room temperature powder X-ray diffraction (XRD), Raman spectroscopy, high resolution transmission electron microscopy and ab initio electronic structure calculations. In light of the above structural characterization, a possible mechanism for the formation of the specific shape of hexagonal bi-pyramid is proposed. Our investigations on optical, photocatalytical and wetting characteristics of the as-grown nanocrystals demonstrate their visible light photocatalytic activity as well as a strong-hydrophilic character. The material is poised to establish itself as a new “self-cleaning” material.