Filters

2019 - 201912020 - 20211

More filters

20212
Reset filters

Settings

Author: Biswal, Bishnu P. ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Thiophene-Bridged Donor–Acceptor sp2-Carbon-Linked 2D Conjugated Polymers as Photocathodes for Water Reduction
    (Weinheim : Wiley-VCH, 2021) Xu, Shunqi; Sun, Hanjun; Addicoat, Matthew; Biswal, Bishnu P.; He, Fan; Park, SangWook; Paasch, Silvia; Zhang, Tao; Sheng, Wenbo; Brunner, Eike; Hou, Yang; Richter, Marcus; Feng, Xinliang
    Photoelectrochemical (PEC) water reduction, converting solar energy into environmentally friendly hydrogen fuel, requires delicate design and synthesis of semiconductors with appropriate bandgaps, suitable energy levels of the frontier orbitals, and high intrinsic charge mobility. In this work, the synthesis of a novel bithiophene-bridged donor–acceptor-based 2D sp2-carbon-linked conjugated polymer (2D CCP) is demonstrated. The Knoevenagel polymerization between the electron-accepting building block 2,3,8,9,14,15-hexa(4-formylphenyl) diquinoxalino[2,3-a:2′,3′-c]phenazine (HATN-6CHO) and the first electron-donating linker 2,2′-([2,2′-bithiophene]-5,5′-diyl)diacetonitrile (ThDAN) provides the 2D CCP-HATNThDAN (2D CCP-Th). Compared with the corresponding biphenyl-bridged 2D CCP-HATN-BDAN (2D CCP-BD), the bithiophene-based 2D CCP-Th exhibits a wide light-harvesting range (up to 674 nm), a optical energy gap (2.04 eV), and highest energy occupied molecular orbital–lowest unoccupied molecular orbital distributions for facilitated charge transfer, which make 2D CCP-Th a promising candidate for PEC water reduction. As a result, 2D CCP-Th presents a superb H2-evolution photocurrent density up to ≈7.9 µA cm−2 at 0 V versus reversible hydrogen electrode, which is superior to the reported 2D covalent organic frameworks and most carbon nitride materials (0.09–6.0 µA cm−2). Density functional theory calculations identify the thiophene units and cyano substituents at the vinylene linkage as active sites for the evolution of H2. © 2020 The Authors. Advanced Materials published by Wiley-VCH GmbH
  • Thumbnail Image
    Item
    A thiazolo[5,4-: D] thiazole-bridged porphyrin organic framework as a promising nonlinear optical material
    (London : Royal Society of Chemistry (RSC), 2019) Samal, Mahalaxmi; Valligatla, Sreeramulu; Saad, Nabil A.; Rao, M. Veeramohan; Rao, D. Narayana; Sahu, Rojalin; Biswal, Bishnu P.
    Porphyrin-based porous organic frameworks are an important group of materials gaining interest due to their structural diversity and distinct opto-electronic properties. However, these materials are seldom explored for nonlinear optical (NLO) applications. In this work, we investigate a thiazolo[5,4-d]thiazole-bridged porous, porphyrin framework (Por-TzTz-POF) with promising NLO properties. The planar TzTz moiety coupled with integrated porphyrin units enables efficient π-conjugation and charge distribution in the Por-TzTz-POF resulting in a high nonlinear absorption coefficient (β = 1100 cm GW-1) with figure of merit (FoM) σ1/σ0 = 5571, in contrast to analogous molecules and material counterparts e.g. metal-organic frameworks (MOFs; β = ∼0.3-0.5 cm GW-1), molecular porphyrins (β = ∼100-400 cm GW-1), graphene (β = 900 cm GW-1), and covalent organic frameworks (Por-COF-HH; β = 1040 cm GW-1 and FoM = 3534). This journal is © The Royal Society of Chemistry.