Acid-Modulated Synthesis of Novel π-Conjugated Microporous Polymers for Efficient Metal-Free Photocatalytic Hydrogen Evolution.

Simple synthetic modifications that tune the molecular structures, thereby the properties of the molecules, are of topical interest. Herein, we report the synthesis of two novel cationic rosaniline-based conjugated microporous polymers (CMPs) from identical monomers via simple acid modulation (Acetic acid and BF  ⋅ Et O). The condensation reaction of rosaniline with 2,4,6-triformylphloroglucinol in acetic acid renders β-ketoenamine-linked CMP (CMP-A) while changing the acid to BF  ⋅ Et O, the linkages transform to enol and undergoes BF -complexation, leading to boranil CMP (CMP-B).

Specific locations of blue and green-emitting units in dual emissive carbon dots and their reversible emitting properties due to switchable inter-chromophoric interactions.

Carbon dots (CDs) are the unique class of luminescent nanomaterials consist of various chromophoric units heterogeneously distributed throughout the nanoparticle, resulting intriguing multistate emissive properties. Herein, we have critically investigated the specific locations of the blue and green-emitting centers inside dual emissive CDs by steady-state and time-resolved polarized emission study. It is further clarified by a temperature-dependent fluorescence study for both the emitting domains.

Insight into the Multistate Emissive N, P-doped Carbon Nano-Onions: Emerging Visible-Light Absorption for Photocatalysis.

Carbon dots (CDs) have become one of the most emerging materials as an alternative solar light-induced photocatalyst in contrast to traditional metal-based systems. However, one of the major challenges is the lack of visible light absorption. Herein, we have fabricated unique N, P-co-doped CDs with a self-assembled onion-like layered structure by using a bottom-up facile synthesis technique from chitosan gel and phosphoric acid as molecular precursors.

Carbon-based nanomaterials: in the quest of alternative metal-free photocatalysts for solar water splitting.

One of the alarming problems of modern civilization is global warming due to the inevitable rise of CO in the environment, mainly because of the excessive use of traditional fossil fuels. The gradual depletion of fossil fuels is another challenge regarding the future energy demand; therefore, alternative renewable energy research is necessary. One of the alternative approaches is the solar fuel generation by means of photocatalytic water splitting and more specifically, hydrogen evolution from water through the reductive half-reaction.

Low-cost electrochemical detection of l-tyrosine using an rGO-Cu modified pencil graphite electrode and its surface orientation on a Ag electrode using an spectroelectrochemical method.

A low cost reduced graphene oxide-copper hybrid nano thin-film modified Pencil Graphite Electrode has been employed to detect the l-tyrosine enantiomer. The free-standing rGO-Cu hybrid nano-thin film was prepared by a simple one-step liquid-liquid interface method. Electrochemical Cyclic Voltammetry, Differential Pulse Voltammetry, pH-dependent and scan rate dependent studies on bare PGE, Cu, rGO, and rGO-Cu for l-tyrosine have been explained in detail.

Graphene-Augmented Polymer Stabilization: Drastically Reduced and Temperature-Independent Threshold and Improved Contrast Liquid Crystal Device.

Polymers reinforced with nanofillers, especially graphene in recent times, have continued to attract attention to realize novel materials that are cheap and also have better properties. At a different level, encapsulating liquid crystals (LCs) in polymer networks not only adds mechanical strength, but could also result in device-based refractive index mismatch. Here, we describe a novel strategy combining the best of both these concepts to create graphene-incorporated polymer-stabilized LC (PSLC) devices.

Single sea urchin-MoO nanostructure for surface enhanced Raman spectroscopy of dyes.

Enhancing the surface-enhanced Raman scattering (SERS) activity of semiconductor metal oxide nanostructures by controlling the morphology and oxygen vacancies towards trace detection of organics is of significant interest. In this study, MoO with a novel sea urchin morphology is synthesized employing chemical bath deposition and consists of hundreds of ∼15 μm long spikes originating from the core forming 20-40 micron globular structures. The spikes taper to form 20 nm sharp tips.

Films of Reduced Graphene Oxide with Metal Oxide Nanoparticles Formed at a Liquid/Liquid Interface as Reusable Surface Enhanced Raman Scattering Substrates for Dyes.

Free standing, thin films of reduced graphene oxide (rGO) with ZnO, CuO and SnO(2) nanostructures are prepared at a water/toluene interface utilizing simple interfacial reaction and self-assembly. rGO-ZnO, rGO-CuO and rGO-SnO(2) films exhibit unique morphologies such as hexagonal cylinders, elongated splinters, and balls, respectively, wrapped by rGO layers. The hybrid films exhibit surface enhanced Raman scattering (SERS) of rhodamine 6G dye with enhancement factors one order higher than bare metal oxide caused by a synergic effect of charge transfer between the dye, metal oxide and rGO.

Improved surface-enhanced Raman and catalytic activities of reduced graphene oxide-osmium hybrid nano thin films.

Reduced graphene oxide-osmium (rGO-Os) hybrid nano dendtrites have been prepared by simple liquid/liquid interface method for the first time. The method involves the introduction of phase-transfered metal organic precursor in toluene phase and GO dispersion in the aqueous phase along with hydrazine hydrate as the reducing agent. Dendritic networks of Os nanoparticles and their aggregates decorating rGO layers are obtained.

Hybrid materials of ZnO nanostructures with reduced graphene oxide and gold nanoparticles: enhanced photodegradation rates in relation to their composition and morphology.

Binary and ternary hybrid systems of ZnO possessing nanoparticle and nanorod morphologies on reduced graphene oxide (rGO) and rGO with Au nanoparticles are explored as photocatalysts and a comparative study of their photodegradation performance is presented. Various preparation methods such as solution phase and hydrothermal routes have been employed to produce rGO-ZnO hybrids and rGO-Au-ZnO hybrids to impart different morphologies and defect states in ZnO. All the hybrids exhibit faster photodegradation kinetics and the rGO-Au-ZnO system exhibits the highest rate, five times faster than bare ZnO, followed by the binary systems, rGO-ZnO nanoparticles and nanorods.

Excited state electron transfer from aminopyrene to graphene: a combined experimental and theoretical study.

The quenching of the fluorescence of 1-aminopyrene (1-Ap) by reduced graphene oxide (rGO) has been investigated using spectroscopic techniques. In spite of the upward curvature in the Stern-Volmer plot, the unchanged spectral signature of the absorption of 1-Ap in the presence of rGO and the decrease in fluorescence lifetime with increasing rGO concentration point toward the dynamic nature of the quenching. Detailed analysis of steady state and time-resolved spectroscopic data has shown that the quenching arises due to the photoinduced electron transfer from 1-Ap to rGO.