Ultrafine Ruthenium-Embedded P-Doped Carbon Materials as Bifunctional Catalysts for Solar-Assistant Water Splitting

The development of advanced bifunctional electrodes with high activity and durability is essential for the development of simplified overall water-splitting systems. Herein, we report ruthenium-based P-doped carbon (RuOx/P–C) hybrids as high bifunctional activity catalysts, where lignin and phytic acid were used as C and P sources, respectively, to form lignin–phytic acid networks via complexation and electrostatic interaction. The resulting RuOx/P–C catalysts exhibit enhanced catalytic performance for solar-assistant water splitting. For the hydrogen evolution reaction (HER), RuOx/P–C achieves low onset potentials of 24 mV (1.0 M H2SO4) and 30 mV (1.0 M KOH) at 10 mA cm–2, as well as small Tafel slopes of 33 and 30 mV dec–1, respectively. For the PEC cell, RuOx/P–C/W:BiVO achieves a photocurrent of 1.08 mA cm–2 at 1.23 V, which is 1.3 times higher than that of pristine W:BiVO. The above results are attributable to the synergistic coupling effects among active species.