Convenient hydrothermal treatment combining with “Ship in Bottle” to construct Yolk-Shell N-Carbon@Ag-void@mSiO2 for high effective Nano-Catalysts

•A low-cost, simple, and efficient strategy prepares yolk-shell nano-catalyst.•Charge interaction is the main reason for constructing the core–shell structure.•High temperature treatment provides position for loading Ag on the core surface.•The ship in bottle mindset is used to load metal on the core surface of yolk-shell.•Ag+ is reduced by –NH- and –NH2 on the core surface without additional reductant.