Photocatalytic Activities of Layered Niobate Perovskite (A'A_n−1Nb_nO_3n+1, A: Ca, La) with Substitution of Ti and W for Nb

抄録

A novel series of Dion-Jacobson type layered perovskite RbLaNb_2−2xTi_xW_xO₇ (x=0, 0.1, and 0.2) and KCa₂Nb_3−2xTi_xW_xO₁₀ (x=0, 0.15, and 0.3) have been synthesized. The XRD patterns confirm that the optimum conditions for synthesis of RbLaNb_2−2xTi_xW_xO₇ and KCa₂Nb_3−2xTi_xW_xO₁₀ are 1000 and 1100 degree for 6 h, respectively. The estimated optical band gap energies of RbLaNb₂O₇, RbLaNb_1.8Ti_0.1W_0.1O₇ and RbLaNb_1.6Ti_0.2 W_0.2O₇ are 3.21, 3.18 and 3.11, respectively. The influence of the partial substitution of Ti and W on the photo-catalytic activity of pure RbLaNb₂O₇ was evaluated by using the degradation of phenol for 4 hours. At the end of experiment, the normalized concentration of phenol is 0.9, 0.8, 0.5 by RbLaNb₂O₇, RbLaNb_1.8Ti_0.1W_0.1O₇ and RbLaNb_1.6Ti_0.2W_0.2O₇ respectively, which indicates that the substitution of Ti and W for Nb in RbLaNb₂O₇ layered perovskites could increase the photocatalytic efficiency. The photocatalytic activities of KCa₂Nb_3−2xTi_xW_xO₁₀ were also tested and the result has been shown that the phenol degradation by RbLaNb_2−2xTi_xW_xO₇ is better than KCa₂ Nb_3−2xTi_xW_xO₁₀.