Indian Institute of Technology Guwahati

About: Indian Institute of Technology Guwahati is a education organization based out in Guwahati, Assam, India. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 6933 authors who have published 17102 publications receiving 257351 citations.

Inner Filter Effect Based Selective Detection of Nitroexplosive-Picric Acid in Aqueous Solution and Solid Support Using Conjugated Polymer

Abstract: A new polyfluorene derivative, poly[4,4′-(((2-phenyl-9H-fluorene-9,9-diyl)bis(hexane-6,1-diyl))bis(oxy))dianiline)] (PFAM) was synthesized via the Suzuki coupling polymerization method in high yields for the rapid and specific recognition of nitroexplosive picric acid (PA) at 22.9 picogram level on solid support using paper strips and at 13.2 ppb level in aqueous solution. The polymer PFAM was well-characterized by means of NMR, UV–vis, fluorescence, time-resolved photoluminescence (TRPL) spectroscopy and cyclic voltammetry. The amplified signal response exclusively for PA was achieved via a strong inner filter effect (IFE), a phenomenon different from the widely reported ground-state charge transfer and/or Forster resonance energy transfer (FRET) based probes for nitroaromatics detection. Pendant amine groups attached on the side chains of PFAM provide enhanced sensitivity and exceptional selectivity via protonation assisted photoinduced electron transfer (PET) even in the presence of most common interfe...

Hydrogen Evolution Reaction Activity of Graphene–MoS2 van der Waals Heterostructures

Abstract: Determining a suitable noble-metal-free catalyst for hydrogen evolution reaction (HER) by photoelectrocatalytic (PEC) water splitting is an enduring challenge. Here, the molecular origin of number of layers and stacking sequence-dependent PEC HER performance of MoS2/graphene (MoS2/GR) van der Waals (vdW) vertical heterostructures is studied. Density functional theory (DFT) based calculations show that the presence of MoS2 induces p-type doping in GR, which facilitates hydrogen adsorption in the GR side compared to the MoS2 side with ΔGH closer to 0 eV in the MoS2/GR bilayer vertical stacks. The activity maximizes in graphene with monolayer MoS2 and reduces further for bilayer and multilayers of MoS2. The PEC HER performance is studied in various electrodes, namely, single-layer graphene, single- and few-layered MoS2, and their two different types of vertical heterojunctions having different stacking sequences. The graphene on top of MoS2 sequence showed the highest photoresponse with large reaction curren...