Promotion of hydrogen evolution from seawater via poly(aniline-co-4-nitroaniline) combined with 3D nickel nanoparticles

This work reports the synthesis of poly (aniline-co-4-nitroaniline) deposited on a three-dimensional nanostructured nickel (3D-Ni) film, where both layers were fabricated via potentiostatic electrodeposition. The obtained electrocatalyst exhibited excellent electrochemical activity for the Hydrogen Evolution Reaction (HER) with small overpotentials of − 195 and − 325 mV at − 10 and − 100 mAcm −2 , respectively, and a low Tafel slope of 53.3 mV dec −1 in seawater. Additionally, the electrocatalyst exhibited good stability after 72 h operation under a constant potential of − 1.9 V vs . RHE. The efficient HER performance of the as -prepared catalyst was found to originate from the synergy between the conducting polymer and three-dimensional nickel nanoparticles with a large electrochemical active surface area. Moreover, the results obtained from electrochemical impedance spectroscopy (EIS) measurements revealed that the presence of 3D-Ni layer improved the kinetics of HER by reducing the charge transfer resistance for the electrocatalyst.