Iron Doped Titania/Polyaniline Composite: An Efficient Electrocatalyst for Hydrogen Evolution Reaction in Acidic Medium

The development of noble metal-free catalyst for hydrogen evolution reaction (HER) is the primary challenge in fuel production to replace fossil fuels. Here, we have synthesized Fe-doped TiO2/PANI nanocomposite via facile in situ polymerization method and studied its electrocatalytic activity towards HER. The composite catalyzes HER efficiently with an overpotential value of -180 mV vs. RHE in 0.5 M H2SO4 solution to achieve the current density of 10 mA cm-2 and also possesses unique stability of 8 h. However, a unique balance of PANI content must be maintained to draw the maximum efficiency from the conjuncture of active Fe-doped TiO2 particles and PANI. The catalytic efficiency of PANI is upgraded by interfacial electronic coupling with Fe-doped TiO2, due to which the antibonding states of nitrogen atom got occupied, leading to a weaker interaction between adsorbate hydrogen and catalyst surface and enhancing the rapid desorption of H2.