Rational design and synthesis of hetero-nanostructured electrospun PU@PANI@FeS2: A surface tailored hybrid catalyst for H2 production via electrochemical splitting of water

The rational design of potential and stable electro-catalyst, which yields high hydrogen evolution is most emerging research area and is of great challenge. In this work, we present a simple method for the fabrication of hybrid electrocatalyst, PU@PANI@FeS2, composed of polyurethane (PU), polyaniline (PANI) and iron sulphide (FeS2). Initially, The PU nanofibers of diameter of 200–300 nm were fabricated by electrospinning process. Then, FeS2 together with PANI were deposited on electrospun PU nanofibers via simultaneous precipitation and polymerization. The prepared PU@PANI@FeS2 was thoroughly characterized using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD results confirm the formation of pure FeS2 on PU@PANI. The PU@PANI@FeS2 was tested as an electrocatalyst to catalyse hydrogen evolution reaction (HER) and compared its electrochemical activity with NiS2 and SnS2 nanocomposites. The PU@PANI@FeS2 exhibits enhanced HER activity, where it demonstrates low overpotential of 266 and 372 mV to generate 10 mA/cm2 and 50 mA/cm2, respectively. The excellent HER activity of PU@PANI@FeS2 may be due to the cooperative effect of FeS2 and PANI, where FeS2 provides abundant active sites and PANI enhances the conductivity.