Making large-scale, multifunctional, paper-like, free-standing membranes (FSM) and the FSM-based 3D macroscopic devices purely from long inorganic functional nanowires is challenging in many nanomaterials systems. Here we report synthesis of long nanowires of the catalytic titanate for direct fabrications of the FSM and the FSM-based 3D devices that are among the first to show unusual potentials in photocatalysis, write-erase-rewrite, microfiltration, and controlled release.