Fabrication of Ti/TiO₂ and Cu/TiO₂ Composite Photocatalyst by Spark Plasma Sintering and its Characteristics

Abstract

Ti/TiO₂ and Cu/TiO₂ composite photocatalysts were fabricated by spark plasma sintering (SPS) technique. TiO₂ powder (ST-01, Ishihara Sangyo Kaisha, LTD.) with an average diameter of 7 nm was used as the matrix material. Ti powder with 99.8 % purity and an average diameter of 35 μm and Cu powder with 99.9 % purity and an average diameter of 30 μm were used as the addition metals, respectively. The sintering was carried out at 973 K for 3 min with a heating rate of 100 K/min under a uniaxial pressure of 30 MPa. The microstructure and crystal form of the composite photocatalysts were examined by SEM and XRD. The photocatalytic activity of the composite photocatalysts was evaluated by measuring the decomposition rate of methylene blue (MB) solution at room temperature. The results show that TiO₂ photocatalyst fabricated at 973 K had the high activity, and that anatase crystal form was kept for the composite photocatalyst with 0∼5 wt%Ti, but the composite photocatalysts with 10 wt%Ti had two crystal forms, anatase and rutile. Antase crystal form was kept for all Cu/TiO₂ composite photocatalyst. High photocatalytic activity was obtained because of the composite effect. Photocatalytic activity goes up with addition amount of Ti or Cu powder and reached the maximum about 1 vol%, then goes down.