Synthesis and photochromism of tungstophosphate-functionalized ordered mesoporous hybrid silica.

New tungstophosphate-functionalized ordered mesoporous silica was synthesized based on monovacant PW11 and block copolymer template. Upon characterizations of the as-obtained PW11/MHS samples by FT-IR, XRD, ICP-AES and N2 adsorption-desorption measurements, it was revealed that Keggin units were retained perfectly in hexagonally symmetrical mesopore channels and bound covalently onto the pore walls of mesoporous silica. The material exhibits stable and reversible photochromic property upon UV irradiation even though no a special organic component was supplied as electron donor. This may provide a new approach to construct photochromic materials of potential applications in high-density optical memories and other optical devices.