Development of 1D-Metalloid-Induced Highly Porous Carbon Nanofiber Conjugated with PEDOT Polymer Through Concurrent Selenization of ZIF-67 for Energy Storage and Green H2 Production.

Manufacturing high-performance and cost-affordable non-metallic, electroactive 1D carbon material for energy storage and hydrogen evolution reaction (HER) is of foremost importance to respond positively to the impending energy crisis. Porous N-doped carbon nanofiber (PNCNF) is successfully synthesized by electrospinning, using selenium nanoparticles as a sacrificial template (where Se is reutilized for ZIF-67 selenization as a bi-process, and the surface of PNCNF is modified with poly(3,4-ethylenedioxythiophene) (PNCNT/PEDOT) by electropolymerization. The prepared materials are found ideal for energy storage (supercapacitor) and electrocatalysis (HER). The bi-functional material has shown excellent energy storage capability with the specific capacitance (CS) of 230 F g-1 (PNCNF) and 395 F g-1 (PNCNF/PEDOT), and the symmetric supercapacitor device, PNCNF/PEDOT//PEDOT/PNCNF, exhibits 32.4 Wh kg-1 energy density at 14400 W kg-1 power density with 96.6% Coulombic efficiency and 106% CS at the end of 5000 charge-discharge cycles. The rate capability of the symmetric supercapacitor cell of PNCNF/PEDOT is 51% for the current density increase from 1 to 8 A g-1, while that of PNCNF is a meager 29% only. Electrocatalytic HER at the PNCNF electrode is achieved with an overpotential of 281 mV@10 mA cm-2 relative to the Pt/C electrode and a low Tafel slop value of 96 mV dec-1.

Trends in Paper-Based Sensing Devices for Clinical and Environmental Monitoring.

Environmental toxic pollutants and pathogens that enter the ecosystem are major global issues. Detection of these toxic chemicals/pollutants and the diagnosis of a disease is a first step in efficiently controlling their contamination and spread, respectively. Various analytical techniques are available to detect and determine toxic chemicals/pathogens, including liquid chromatography, HPLC, mass spectroscopy, and enzyme-linked immunosorbent assays. However, these sensing strategies have some drawbacks such as tedious sample pretreatment and preparation, the requirement for skilled technicians, and dependence on large laboratory-based instruments. Alternatively, biosensors, especially paper-based sensors, could be used extensively and are a cost-effective alternative to conventional laboratory testing. They can improve accessibility to testing to identify chemicals and pollutants, especially in developing countries. Due to its low cost, abundance, easy disposal (by incineration, for example) and biocompatible nature, paper is considered a versatile material for the development of environmentally friendly electrochemical/optical (bio) sensor devices. This review presents an overview of sensing platforms constructed from paper, pointing out the main merits and demerits of paper-based sensing systems, their fabrication techniques, and the different optical/electrochemical detection techniques that they exploit.