TiO2 inverse opal photonic crystals: Synthesis, modification, and applications - A review

TiO2 inverse opal photonic crystal (TiO2 IO PCs) that possesses the advantages of titanium dioxide including non-toxicity, high refractive index (>2.5), good biocompatibility etc. and the optical characteristics of photonic crystals containing the band gap, photonic localization, slow light effect, super prism effect and negative refraction effect has attracted tremendous interest. Its synthetic methods are usually chemical vapor deposition, atomic layer deposition, electrochemical deposition and sol-gel method. To meet the needs of the applications in chemical sensors, solar cells, photocatalysis, high efficient microwave wire, photonic crystal fiber etc., lots of research focused on the modifications of TiO2 IO PCs by means of noble metal deposition, non-metal elements or metal ion doping, quantum dot sensitization and semiconductor composite. This paper aims to review the up-to-date synthesis, modification, and applications of TiO2 IO PCs and forecast its future development direction.