Pb²⁺—N Bonding Chemistry: Recycling of Polyaniline–Pb Nanocrystals Waste for Generating High-Performance Supercapacitor Electrodes

Abstract

Understanding of PbN bonding chemistry is not only fundamentally important in the view of relativistic inert-pair effect but also is important for therapeutic as well as environmental applications. In the present study, an unusual reactivity of N-containing π-conjugated polyaniline emeraldine base (EB) toward aqueous Pb2+ ions has been identified. In the course of sequestering Pb2+ ions by EB, cuboid-shaped nanocrystals were isolated. Synchrotron-based X-ray absorption near-edge structure and extended X-ray absorption fine structure techniques were employed to understand Pb–N bonding chemistry in EB-Pb nanocrystals. The adopted methodology of slow exposure of HCl vapor to EB-Pb nanomaterial facilitated the isolation of polyaniline emeraldine-salt (ES) with unique morphological patterns, porosity and electrical conductivity. The electrochemical device based on recycled ES showed high-capacitance value (∼606 F/g @1 A/g and ∼663 F/g @10 mV/s), high-energy density (∼14.8 Wh/kg at power density of ∼663 W/kg) and excellent-cycling stability (only ∼15% degradation after 1100 continued cycles at current density of 5 A/g). Notably, ES materials prepared directly from EB and upon exposing HNO3 vapor exhibited greatly inferior device performance.

Polyaniline–graphene oxide nanocomposites: Influence of nonconducting graphene oxide on the conductivity and oxidation‐reduction mechanism of polyaniline

“…These results justify the synergistic effect of GO and PANi on its electrochemical activity with 5% being the threshold concentration of GO in the composite with highest magnitude of current and appreciable loop area (property useful for supercapacitors) . Incorporation of low concentrations of GO (up to 5%) in the composites facilitates the electrolyte percolation to the active material resulting in decreased overall internal resistance of the electrode.…”

Giant Enhancement of Carrier Mobility in Bimetallic Coordination Polymers

“…Measured data points in the Nyquist plots were fitted with a modified Randle circuit (Figure 7a−d). 40,41 The electrical conductivity values of Fe−BTC, Cr− BTC, and Fe−BTC−Cr (1:1) measured by EIS were found to be ∼3.0 × 10 −6 , ∼5.0 × 10 −8 , and ∼1.5 × 10 −4 S cm −1 , respectively. Indeed, the overall trend in the electrical conductivity reflected by the EIS technique was very similar to that observed with the four-probe technique; specifically, bimetallic CPs consistently exhibited much higher electrical conductance than monometallic parent CPs.…”

High-Level Supercapacitive Performance of Chemically Reduced Graphene Oxide

“…[14][15][16][17] Unlike conducting polymers or metal oxides, graphene falls into the category of an electric double-layer capacitor (EDLC) and thus does not have to go through vigorous chemical reactions or transformations causing severe material degradation during charge-discharge cycles. [18][19][20] Apart from ballistic transport of charges, a single layer of graphene can in principle achieve an intrinsic EDLC of $21 mF/cm 2 , and with the complete surface area, an EDLC of graphene could reach as high as $550 F/g (theoretically set) along with high energy density, high power density, and long-term stability. 2,4,17 However, obtaining a single layer of graphene on a large-scale by simple physical or chemical methods to meet industrial needs remains challenging.…”