Biomimetic　solid-state　nanofluidic　diodes　have　attracted　extensive　research　interest　due　to　the　possible　applications　in　various　fields,　such　as　biosensing,　energy　conversion,　and　nanofluidic　circuits.　However,　contributions　of　exterior　surface　to　the　transmembrane　ionic　transport　are　often　ignored,　which　can　be　a　crucial　factor　for　ion　rectification　behavior.　Herein,　a　rational　design　of　robust　sandwich-structured　nanofluidic　diode　is　shown　by　creating　opposite　charges　on　the　exterior　surfaces　of　a　nanoporous　membrane　using　inorganic　oxides　with　distinct　isoelectric　points.　Potential-induced　changes　in　ion　concentration　within　the　nanopores　lead　to　a　current　rectification;　the　results　are　subsequently　supported　by　a　theoretical　simulation.　Except　for　providing　surface　charges,　functional　inorganic　oxides　used　in　this　work　are　complementary　electrochromic　materials.　Hence,　the　sandwich-structured　nanofluidic　diode　is　further　developed　into　an　electrochromic　membrane　exhibiting　a　visual　color　change　in　response　to　redox　potentials.　The　results　show　that　the　surface-charge-governed　ionic　transport　and　the　nanoporous　structure　facilitate　the　migration　of　Li+　ions,　which　in　turn　enhance　the　electrochromic　performance.　It　is　envisioned　that　this　work　will　create　new　avenues　to　design　and　optimize　nanofluidic　diodes　and　electrochromic　devices.