Effect of solvent and dispersion method on enhancing the performance of hydrogel-based conductive electrodes for oxygen evolution reactions

Conductive hydrogels are promising materials for electrochemical energy conversion due to their ability to integrate catalytic particles within a conductive network. This study investigates an innovative approach based on examining the influence of solvent selection and dispersion method on the electrochemical properties of a poly(N-isopropylacrylamide) (PNIPAM) hydrogel electrodes for the oxygen evolution reaction (OER). Hydrogels were prepared using water, water-ethanol, or poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as solvents, and MnCo 2 O 4 (MCO) with conductive carbon black (cCB) were dispersed either by magnetic stirring or ultrasonication. PEDOT:PSS combined with ultrasonication yielded the most homogeneous composites, significantly enhancing electrical conductivity and catalytic activity. The optimized hydrogel exhibited a reduced OER overpotential of 396 at 10 mA cm −2 , improved kinetics verified by Tafel slope and double-layer capacitance analysis, and lower charge-transfer resistance confirmed by electrochemical impedance spectroscopy. There results demonstrate that solvents choice and dispersion technique, in addition to catalyst composition and concentration, critically determine performance of catalytic electrode based on conductive hydrogel. The findings provide a practical strategy for designing efficient conductive hydrogels for energy conversion applications. • One-step synthesis of PNIPAAm/MCO/cCB and applying it as an OER catalyst. • PEDOT:PSS hydrogel with MCO + cCB particles shows 396 mV OER overpotential at 10 mA/cm 2 . • Solvent choice and carbon content strongly influence hydrogels electrocatalysis. • This study offers new insights into hydrogels for sustainable H 2 production.