Nano-engineering of Ru-based hierarchical porous nanoreactors for highly efficient pH-universal overall water splitting

Abstract Herein, we report a facile methodology for fabricating the hierarchical porous nanostructures riveted with ultrafine Ru nanoclusters as high-performance nanoreactors for overall water splitting from MOF precursors. Benefited from the unique skeletons full of micro/meso/macropores with effective site accessibility and mass transport, the nanoreactors exhibit a remarkable performance for hydrogen evolution reaction (HER) in the overall pH range. Especially, the overpotential (η) of such nanoreactors for alkaline HER is only 25 mV@10 mA cm–2 with an ultrahigh turnover frequency (TOF) value of 2.04 H2 S–1 at η = 50 mV, greatly surpassing benchmark Pt/C. Moreover, the further conversed RuO2 catalyst well retains the hierarchical porous merits, showing prominent oxygen evolution reaction (OER) activity. Taking advantages of their opulent exposed active sites and efficient charge/mass transport route of both kinds of the nanoreactors, the two-electrode device was constructed for efficient overall water splitting, demonstrating remarkably high H2 generation rates in varied-pH media.