Electrodeposition of Metal‐Free Polyaniline Electrocatalyst for Efficient Oxygen Evolution in Acid

Developing efficient and competitive electrocatalysts for the oxygen evolution reaction (OER) in acid is a great challenge for hydrogen production. Compared with metal catalysts, metal‐free catalysts are more environmentally friendly and cheaper. Herein, we present a novel non‐metallic self‐supporting polyaniline catalyst (PANI3/CFP) synthesized by electrodeposition for efficient water oxidation. Benefiting from the three‐dimensional network structure, excellent conductivity, and large number of nitrogen functional groups, PANI3/CFP exhibits high activity towards OER. At a current density of 10 mA cm−2, PANI3/CFP delivers a low overpotential of 204 mV in 0.1 m HClO4, much lower than commercial Ir/C and previously reported acidic OER catalysts. Besides, the turnover frequency (TOF) value of PANI3/CFP reaches 0.0456 s−1 at 1.5 V versus the reversible hydrogen electrode (vs. RHE). Analysis of structure and electrocatalytic performances reveal that =N− species in polyaniline are the main active sites for acidic OER. This work provides a unique strategy for the design of non‐metallic acidic OER catalysts. Metal‐free PANI3/CFP catalyst is prepared by electrodeposition for acidic oxygen evolution reaction (OER), and its activity is much higher than other samples. The main active sites for acidic OER in PANI3/CFP are =N− species. The disappearance of =N− species and morphological changes will lead to deactivation.