Polyaniline-based electrocatalysts for electrochemical hydrogen evolution reaction

The impact of hydrogen energy on new technology is significant and astounding. However, the environmentally friendly and clean production of hydrogen energy is being investigated and challenged. Water splitting has been regarded as a dazzling and significant source of hydrogen energy, the efficiency of which is highly dependent on the electrocatalysts. Polyaniline (PANI) has been considered as an alternative to replace the commonly used PGM-based electrocatalysts. In this review, the fundamentals and measurement descriptors of HER are briefly introduced. This was followed by closer look at the structure of PANI as well as their synthetic route. Moreover, the strategies to improve HER properties of PANI which include preparation of polyaniline derivatives, copolymers and nanocomposites of PANI with secondary materials such as metal nanoparticles, oxides, phosphide, dichalcogenides, carbon materials and metal organic frameworks comprehensively looked at. Finally, the challenges, solutions and prospects of PANI as HER electrocatalysts are highlighted.