Conductive Polymer Intercalation Tunes Charge Transfer and Sorption-Desorption Properties of LDH Enabling Efficient Alkaline Water Oxidation

Controlling and tuning surface properties of a catalyst have always been a prime challenge for efficient hydrogen production via water splitting. Here, we report a facile method for tuning both charger transfer and sorption-desorption properties of NiFe layered double hydroxide (LDH) by intercalating a conductive polymer of polypyrrole (ppy) via an interlayer confined polymerization synthesis (ICPS) process. Ex situ characterizations and in situ electrochemical quartz-crystal microbalance with dissipation (EQCM-D) tracking experiments showed that the intercalated ppy not only improved the charge transfer property of the resulting hybrid catalyst LDH-ppy but also made it more flexible and adaptive for quick and reversible sorption-desorption of reactants and intermediates during the oxygen evolution reaction (OER) process. Consequently, the as-prepared LDH-ppy exhibited a doubled catalytic current density over the bare LDH, as visualized by in situ scanning electrochemical microscopy (SECM) at the subnanometer scale. This work sheds light on orchestrating the charge and sorbate transfer abilities of catalysts for efficient water splitting by smartly combining inorganic and organic layers.