  Two-dimensional (2D) heterostructuring is a versatile methodology for
designing nanoarchitecture catalytic systems that allow for reconstruction and
modulation of interfaces and electronic structures. However, catalysts with
such structures are extremely scarce due to limited synthetic strategies. Here,
we report a highly ordered 2D Ru/Si nano-heterostructures (RSHS) by acid
etching of the LaRuSi electride. RSHS shows a superior electrocatalytic
activity for hydrogen evolution with an overpotential of 14 mV at 10 mA/cm2 in
alkaline media. Both experimental analysis and first-principles calculations
demonstrate that the electronic states of Ru can be tuned by strong
interactions of the interfacial Ru-Si, leading to an optimized hydrogen
adsorption energy. Moreover, due to the synergistic effect of Ru and Si, the
energy barrier of water dissociation is significantly reduced. The unique
nanostripe structure with abundant interfaces in RSHS will provide a paradigm
for construction of efficient catalysts with tunable electronic states and dual
active sites.
