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

The development of advanced bifunctional electro-des 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 perform-ance 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.

Automated summary

In this study, ruthenium-based phosphorus-doped carbon (RuOx/P-C) hybrids were synthesized using lignin and phytic acid as carbon and phosphorus sources, forming lignin-phytic acid networks via complexation and electrostatic interaction. The resulting RuOx/P-C catalysts exhibited enhanced catalytic performance for solar-assisted water splitting. For the hydrogen evolution reaction, RuOx/P-C achieved low onset potentials and small Tafel slopes in acidic and alkaline electrolytes. In the photoelectrochemical cell, RuOx/P-C/W:BiVO showed a significantly higher photocurrent compared to pristine W:BiVO, attributed to the synergistic coupling effects among active species.