A mild, template free protocol has been demonstrated for SnS2 nanoflake formation at the gram level from SnCl2 and thioacetamide (TAA). The SnS2 nanoflakes congregate to nanoflowers and nanoyarns with variable TAA concentrations. BET measurements reveal that the synthesized nanomaterials are highly porous having very high surface area, and the nanoflower has higher surface area than the nanoyarn. The synthesized nanomaterial finds application for promoting photoreduction of extremely toxic and lethal Cr(VI) under visible light irradiation due to their porous nature. The nanoflowers photocatalyst is proved to be superior to nanoyarn due to the increased surface area and higher pore volume. It was also inferred that increased pH decreased the reaction rate. The present result suggests that the morphology-dependent photoreduction of Cr(VI) by SnS2 nanomaterial under visible light exposure will endorse a new technique for harvesting energy and purification of wastewater.

Ultrathin 2D Co3O4 and Co3V2O8 nanosheets have been produced from our modified hydrothermal technique (MHT). Both the materials have been proved to be extraordinary electrode materials for pseudocapacitors. The neat nanosheets of Co3O4 and Co3V2O8 exhibit a record specific capacitance value of 1256 F g(-1) and 4194 F g(-1) at 1 A g(-1) current density, respectively.

We report a simple, facile, surfactant-free chemical route to fabricate morphologically different Cu2O nanoparticles such as octahedron, truncated octahedron, hollow octahedron, cube, and sphere by varying the hydrolyzing agents, complexing agent, and reducing agents. Then the componential and morphological evolution of Cu2O nanoparticles have been studied independently, employing different etching agents such as aqueous NaOH, triethylamine (TEA), and oxalic acid solution. Particles of varied shapes and compositions resulted from the etching, and those particles were characterized by different physical methods. The oxidative dissolution of morphologically different Cu2O nanoparticles with different etching agents depends on the exposed crystal planes. During oxidative dissolution in aqueous oxalic acid solution, it is realized that the stability of the (100) crystal plane is higher than that of the (111) crystal plane. Among all the etching reagents used, only oxalic acid exhibits shape transformation of the as-prepared Cu2O nanoparticles. Oxalic acid etching causes the formation of cubes and hollow cubes as etching products with a 50% reduction of edge length compared to that of octahedral, truncated octahedral, and hollow octahedral Cu2O nanoparticles. But ill-defined cubes are always obtained as the etching products with a 40% reduction of size compared to that of Cu2O cubes and spheres. As-prepared Cu2O nanoparticles and chemically etched products exhibit facet-dependent photocatalytic activity under visible light irradiation where mineralization of congo red takes place. Experimentally it has been concluded that photocatalytic activity of different particles bears a close relationship with exposed crystal planes, surface area, and particle size for congo red degradation. Interestingly, NaOH-etched product with hollow octahedral morphology bearing many (111) facets demonstrates the highest photocatalytic activity.

The importance of an interfacial reaction to obtain mesoporous leafy nanostructures of gold and palladium has been reported. A new synthetic strategy involving 1,4-dihydropyridine ester (DHPE) as a potential reducing agent performs exceptionally well for the desired morphologies of both the noble metals at room temperature. The DHPE in turn transforms into its oxidized aromatic form. The as-synthesized gold leaves exhibit high surface-enhanced Raman scattering activity with rhodamine 6G (R6G) due to their hyperbranched structure. It is worthwhile that as-synthesized porous architectures of palladium support the room-temperature hydrogenation of 4-nitrophenol (4-NP) by hydrazine hydrate (N2H4·H2O), reported for the first time. Furthermore, MPL exhibits exceptionally good catalytic activity toward electrooxidation of formic acid. Therefore, an aromaticity driven synthetic technique achieves a rationale to design leafy nanostructures of noble metals from the liquid-liquid interface for multifaceted applications.

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