Interface functionalization of mesoporous ruthenium films with polyaniline for enhanced hydrogen evolution electrocatalysis at all pH values

The design of electrocatalysts with favorable morphologies and surface compositions is an effective strategy to prepare electrocatalysts for the hydrogen evolution reaction (HER). Herein, a polyaniline (PANI) modified mesoporous ruthenium film supported on carbon paper (mRu@PANI/CP) was successfully synthesized by a two-step electrodeposition method at room temperature. With the mesoporous film structure and PANI modification, mRu@PANI/CP displayed superior HER catalytic activity with overpotentials of 30 mV (0.5 M H2SO4), 27 mV (1.0 M KOH), and 24 mV (1.0 M PBS), respectively, at a current density of 10 mA cm−2. This work not only provides a powerful route to prepare a mesoporous Ru film, but also offers a useful interface functionalization strategy to further enhance its electrocatalytic performance, beyond the HER.