Bio-inspired polyhydroxyurethane/polyoxometallate nanocomposite as hydrogen evolution reaction electrocatalyst

Owing to the immense attention on water splitting reactions, finding a suitable electrocatalyst for hydrogen evolution reaction (HER) has gained lot of interests in recent times. Herein, bio-based polyhydroxyurethane nanocomposite with phosphomolybdic acid (PMA@PHU) has been developed as an alternative, efficient low cost electrocatalyst for HER. The impregnation of PMA ions into the PHU matrix is achieved by imparting hydrogen bonding interactions of the former with hydroxyl and urethane groups of the later which resulted a core-shell like morphology of the nanocomposite. The presence of Mo in the PMA imparts electrochemical HER activity in PMA@PHU composite for water-splitting in acidic medium and PHU provides the stability of the material. The PMA was blended with PHU by varying the weight % ranging from 75%, 50%, 25% with respect to PHU weight and named as PMA 75 @PHU, PMA 50 @PHU, PMA 25 @PHU, respectively. Among the three, PMA 50 @PHU found to show the highest current density at −100 mA cm −2 with an onset potential of −0.35 V. It also displayed maximum stability for 20,000 seconds. The HER profile of PMA 50 @PHU showed Tafel slopes 177 mV dec −1 and overpotential 187 mV at 10 mA/cm 2 providing a viable path for environmentally friendly sustainable H 2 production. • Green, low cost, and efficient HER catalyst is developed. • PMA/PHU nanocomposite is used as HER catalyst. • Biocompatible and biodegradable PHU is utilized. • New ideas for making environment friendly HER catalyst is put forward.