Alam Venugopal Narendra Kumar

Selective patterning of Prussian blue on N-[3-(trimethoxysilyl)propyl]ethylenediamine capped gold nanoparticle film for electrocatalysis of hydrogen peroxide reduction

In this work, we have demonstrated selective patterning of electrodes coated with N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS) stabilised gold nanoparticles (Sil-AuNps) films with Prussian blue (PB) by continuous electrochemical cycling of Sil-AuNps film modified Indium Tin Oxide (ITO) electrode in K3[Fe(CN6)] solution. The PB formed on gold nanoparticles (PB@Sil-AuNps) exhibits an electrochemical response similar to the PB formed on a bare ITO surface. However, the high spin iron redox state in PB formed on Sil-AuNps shows almost zero peak to peak separation (ΔEp) value in contrast to the finite ΔEp for PB formed on bare ITO. In addition, this selectively patterned PB on Sil-AuNps modified ITO electrode shows characteristic voltammetric responses of both PB and gold in 0.1 M KNO3 and 0.5 M H2SO4 respectively. In order to see the coverage of PB over gold nanoparticles, ITO electrode surface was characterised using scanning electron microscopy (SEM) and energy dispersive X-rays analysis (EDX) techniques. Selective patterning of redox mediator on noble metal nanoparticles results in lower film resistivity, which favours high electrocatalytic activity towards hydrogen peroxide electro-reduction. The sensitivity of this modified electrode towards H2O2 is 3.4 nA nM−1.

Formation of nanogap Au–polysilsesquioxane 1D chains for SERS application

Organized assemblies of polysilsesquioxane having specific functional groups were used as templates to synthesise 1D nanochains of Au having 1–2 nm gap silica peapods. The protonated amines in polysilsesquioxanes formed from N-[3-(trimethoxysilyl)propyl]-ethylene diamine bind with AuCl4− leading to formation of monodispersed Au nano-chains by auto reduction.

Mesoporous Co3O4 Nanobundle Electrocatalysts

Tailoring metal oxide nanostructures with mesoporous architectures is vital to improve their electrocatalytic performance. Herein, we demonstrate the synthesis of 2D mesoporous Co3 O4 (meso-Co3 O4 ) nanobundles with uniform shape and size by employing a hard-template method. In this study, the incipient wetness impregnation technique has been chosen for loading metal precursor into the silica hard template (SBA-15). The results reveal that the concentration of a saturated precursor solution plays a vital role in mesostructured ordering, as well as the size and shape of the final meso-Co3 O4 product. The optimized precursor concentration allows us to synthesize ordered meso-Co3 O4 with four to seven nanowires in each particle. The meso-Co3 O4 structure exhibits excellent electrocatalytic activity for both glucose and water oxidation reactions.