130-13-2Relevant articles and documents
Surface grafted hyper-branched polyglycerol stabilized Ag and AuNPs heterogeneous catalysts for efficient reduction of Congo Red
Murugan, Eagambaram,Shanmugam, Paramasivam
, p. 426 - 438 (2016)
Six types of insoluble polymer-supported beads immobilized with Ag and AuNPs nanoparticle catalysts were synthesized using newly prepared three different types of polymer-supported poly(styrene)-co-poly(vinyl benzene chloride) matrix (PS-PVBC), surface grafted with (i) triethanolamine (TEA), (ii) glycidyl trimethyl ammonium chloride (GTMAC) and (iii) hyper-branched polyglycerol (HPG) and Ag and AuNPs as a catalytic moiety and thus yield polymer-supported nanoparticle catalysts viz., PS-PVBC-TEA-AgNPs and AuNPs, PS-PVBC-g-GTMAC-AgNPs and AuNPs and PS-PVBC-g-GTMAC-AgNPs and AuNPs catalyst respectively. These bead-shaped heterogonous nanoparticle catalysts were characterized by UV-Vis, FTIR, FESEM, HRTEM and TGA techniques. The efficiency for stabilization/loading of metal nanoparticles with respect to varied intensities of hyper-branched chain grafted onto their matrix was screened by determining their comparative catalytic activity. The catalytic potential of thse catalysts was inspected through reduction of Congo Red (CR) keeping pseudo first order identical reaction condition. The observed kobs values reveal that irrespective of metal the catalyst derived from hyper-branched polyglycerol as stabilizing agent viz., PS-PVBC-g-HPG-AgNPs and PS-PVBC-g-HPG-AuNPs shows (kobs = 3.98× 10-2 min-1 and kobs = 4.54 × 10-2 min-1) four and two times greater activity than the catalyst derived from TEA and GTMAC hyper-branched chain. Further, for the same reaction PS-PVBC-g-HPG-AuNPs showed more efficiency than the PS-PVBC-g-HPG AgNPs catalyst. The stability and reusability of the superior catalyst viz., PS-PVBC-g-HPG-AuNPs catalyst was observed to be good even at the sixth cycle. This catalyst can be continuously used to conduct the reduction of various dyes in continuous mode operation in industrial scale.
Graphene oxide nanocomposite magnetic microbeads for the remediation of positively charged aromatic compounds
Clamer, M.,Dalla Serra, M.,Micheli, V.,Minati, L.,Speranza, G.
, p. 3333 - 3340 (2020)
Integrating graphene as an inorganic nanostructure within a hydrogel matrix enables the creation of a unique hybrid composite combining the peculiar chemical and physical properties of graphene with the high porosity and stability of hydrogels as for example agarose gel. As a consequence, the resulting material forms a double-network system providing advantages deriving from both the components. In this study, we present the synthesis of novel magnetic porous agarose-based graphene oxide microbeads for the adsorption and separation of positively charged aromatic molecules. The hydrogel-based graphene oxide beads revealed an ultrafast adsorption kinetics for positively charged aromatic dyes. We tested this material for the purification of fluorescent-tagged biomolecules. In addition, reduced graphene oxide microbeads were decorated with palladium nanoparticles, showing a high catalytic activity towards the reduction of dyes by sodium borohydride. Our results show that magnetic agarose based graphene microbeads with enhanced physical-chemical properties can be used for several biochemical applications.
Energy and environmental applications of ultrasonically sulfur doped copper-nickel hydroxides with heterostructures
Karthik, Namachivayam,Edison, Thomas Nesakumar Jebakumar Immanuel,Atchudan, Raji,Sethuraman, Mathur Gopalakrishnan
supporting information, p. 126 - 136 (2017/09/22)
A series of sulfur doped copper-nickel hydroxides with heterojunctions were successfully fabricated on nickel foam by adjusting thiourea volume via a facile sonochemical pathway. The effect of volume of thiourea on the final morphology and chemical composition of the hybrids were also investigated by field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy analyses. Furthermore, the electrochemical performance and catalytic activity of the as-obtained hybrids were also investigated. Among the tested electrode, the hybrid material fabricated using 6 ml of thiourea (TU-6) showed outstanding electrochemical properties comprising a high specific capacitance of about 2708 F g?1 at 5 A g?1. In addition, the TU-6 hybrid (catalyst) material displayed remarkable reductive degradation ability towards azo dyes viz., methyl orange (within 8 min) and congo red (within 20 min) in the presence of sodium borohydride (reducing agent) with fast kinetics and good reproducibility, respectively. The exceptional electrochemical performance and excellent catalytic activity of TU-6 hybrid electrode may be attributed to the formation of catalytically active sulfur doped copper-nickel hydroxides (CuS/Ni3S2/NiOOH) three-interface synergistic effect, and unique porous micro-rosette-like texture which increased the diffusion rate and adsorption capacity. The adopted strategy is a simple and generic way for material fabrication to solve the energy and environmental problems.
