Recent Developments in Conductive Polymer-Based Electro-/Photoelectrocatalytic Materials for Effective Hydrogen/Oxygen Evolution Reactions: A Review

Currently, a substantially greener energy source such as hydrogen fuel cell is an alternative to fossil fuel sources, and much research has been dedicated to achieving highly efficient hydrogen (H₂ gas) generation. In this line, electrochemical water splitting that involves hydrogen and oxygen evolution reactions (HER and OER, respectively) is considered to be the greener and most effective hydrogen-generating procedure with only water as a by-product. However, in the process of successful OER/HER, it is extremely demanding for electrocatalysts with high activity, stability and cost-effectiveness for the water splitting process. Herein, the review proposed promising electrocatalysts such as conductive polymers (CPs) with enhanced catalytic effect with the polymer encapsulation of catalytic material that provides an increase in charge transfer kinetics both in OER/HER. Also, the review highlights the OER and HER mechanism of conducting polymers and their effect on the synergism was discussed in detail. Also, the review detailed the reduced overpotentials, importance and enhancement of catalytic efficiency with various polymers reported in both OER and HER. Here, the choice of polymers can matrix with the inorganic active sites to prevent them from aggregation and the water splitting carried out over the electrode surface results in good conductivity to charge transfer from the electrode to the active sites. In addition, the review discussed the polymers induces the photon effect with photoelectrocatalytic water splitting. Thus, the combing effect with conducting polymers and the materials with catalytic active centers open up a new kind of electrocatalyst for synthesis.