Substitution Effect on the Photocatalytic Degradation by the Series AxBi26-xMo10O68+0.5y (A = Ba, y = 0; A = Bi, La, y 2):A Kinetic Study

The compounds Ba 2 Bi 24 Mo 10 O 68 and La 2 Bi 24 Mo 10 O 69 were synthesized by the ceramic route and characterized by single crystal and powder X-ray diffraction, respectively. The structure of these phases is isostructural with that of Bi 26 Mo 10 O 69 . Along the b axis columns of [Bi 12 O 14 ] units are separated by MoO 4 tetrahedra and noncolumnar A (A = Ba, La) atoms. UV-visible spectra of Bi 2 Mo 10 O 69 , Ba 2 Bi 24 Mo 10 O 68 , and La 2 Bi 24 Mo 10 O 69 suggest that band gap decreases on substitution of La and Ba for Bi at the noncolumnar site. The photocatalytic degradation of water pollutants such as phenol and substituted phenols was studied. All the catalysts show specificity toward nitro substituent at the para position in the aromatic ring.