Low Temperature Synthesis and Characterization of Nanocrystalline Titanium Carbide with Tunable Porous Architectures

Abstract

High surface area, porous titanium carbide films have been synthesized at room temperature via reactive ballistic deposition (RBD). X-ray diffraction and X-ray photoelectron spectroscopy show that evaporative deposition of titanium in an ethylene ambient environment allows for low temperature (35 °C) synthesis of nanocrystalline titanium carbide, a material which typically requires high processing temperatures to produce. Angle-dependent RBD allows for the controlled tuning of TiC nanostructure and porosity where changing the deposition angle from near normal incidence (13°) to more glancing angles (50−85°) changes the film morphology from relatively nonporous, dense TiC to a continuous, reticulated TiC and finally to discrete, nanocolumnar TiC. The influence of the deposition angle on TiC optical constants, porosity, specific surface area, and the pore size distribution has been investigated using hybrid quartz crystal microbalance and ellipsometric porosimetry. Notably, TiC films deposited at 35 °C at an angle of 70° have a specific surface area of 710 m 2 ·g −1 and a mean Kelvin radius of 1.8 nm, making them attractive materials for application in catalysis, energy conversion, and storage.