Titanosilcate porous thin film on silicon nanowire as catalyst for oxidation

Abstract

This research investigated the modification of silicon wafer substrate and preparation of titanium silicalite-1 thin film by using modified silicon nanowires as substrates. Silicon nanowires arrays were modified by using the metal-catalyzed electroless etching (MCEE) method. The length of silicon nanowires was linearly increased with etching time. Titanium silicalite-1 thin films were synthesized on modified silicon substrates using nanosized titanium silicalite-1 particles as seed by hydrothermal treatment. The film formation and catalytic properties were characterized using scanning electron microscope (SEM), X-ray diffractometer (XRD) and nitrogen adsorption-desorption isotherm. It was indicated that microporous materials with MFI structure showed good catalytic activity in the phenol hydroxylation with hydrogen peroxide. Titanium silicalite-1 thin film showed high phenol conversion and hydroquinone selectivity. Although iron-titanium silicalite-1 provided lower phenol conversion, it gave higher selectivity to catechol.