Method of making a porous TiO2 photonic film

摘要

A porous titanium dioxide film having photonic properties is made by etching a titanium substrate in an electrolyte solution in the presence of an electric field. The electrolyte solution can be an organic electrolyte solution. Etching involves providing an electrolyte solution in contact with a pair of electrodes and passing an electric current through the electrolyte solution. The titanium substrate can be one of the pair of electrodes. The current has a wave profile selected from a group consisting of a periodic square profile, a sine wave, a linear profile, or a quintic profile, and is provided either parallel to or perpendicular to a plane of the substrate.

主权项

1. A method of making a porous titanium dioxide structure having a photonic color, the method comprising:
providing a pair of electrodes in contact with an electrolyte solution; anodizing a titanium substrate in the electrolyte solution, by passing an electric current having a voltage or current profile through the electrolyte solution and the pair of electrodes in the presence of a first electric field, thereby forming a layer of dense titanium dioxide from the titanium substrate, wherein the first electric field is applied in a first field direction that is transverse to the titanium substrate; etching part of the layer of dense titanium dioxide in the electrolyte solution, by passing an electric current having the voltage or current profile through the electrolyte solution and the pair of electrodes, in the presence of a second electric field, thereby forming a layer of porous titanium dioxide within part of the layer of dense titanium dioxide and that includes pores extending to an outer surface of the layer of porous titanium dioxide, wherein the second electric field is applied in a second field direction that is parallel to the titanium substrate; and adjusting the voltage or current profile and duration of the voltage or current profile while anodizing the titanium substrate and while etching the layer of dense titanium dioxide, thereby controlling the photonic color of the porous titanium dioxide structure.