Nano-gold supported on TiO2 coated glass-fiber for removing toxic CO gas from air

A process for coating a layer of TiO2 on the surface of glass fiber (Pyrex) was developed to support nano-gold on the fiber. The sol–gel method was utilized. The solution was composed of tetrapropyl titanate (TPT), isopropanol (i-PrOH), HCl and H2O. The XRD pattern indicated that TiO2 was in its anatase form after the coated fiber was calcined at 450 °C. In the preparation of nano-gold on the fibers (coated with TiO2), deposition was performed in a pH-adjusted gold chloride solution. The catalytic activities of the resulting fibers were examined by the oxidation of CO in an air stream at room temperature. The gold containing fibers dried at room temperature contained less metallic gold and exhibited poorer CO oxidation activity than did those dried at 60 °C Moreover, the catalytic activities of the fibers depended on the gold concentration during deposition. Therefore, the gold fibers from the solution with gold concentrations of 2 × 10−4 M exhibited better CO oxidation activity than those from the solutions with concentrations of 1 × 10−3 and 0.7 × 10−4 M. TEM and A.A. analysis show that different concentrations of the gold solution were associated with different particle sizes and different gold loadings on the fibers, and therefore different catalytic activities of the fibers (per unit weight of fibers). 0.1 g of fibers prepared from the 2 × 10−4 M gold solution removed all CO from the air stream (containing 1% CO at a flow rate 110 cm3/min) at room temperature, approximately meeting the European Community EN403 (1993) standard for a qualified CO gas mask material.