Investigation of the photocatalytic properties of a family of calcium bismuth oxides

CHED 1102

Byron H. Farnum, farnumb@mailbox.sc.edu1, Thomas Vogt, tvogt@gwm.sc.edu2, Sangmoon Park, sangmoon@gwm.sc.edu2, and John L. Ferry, ferry@mail.chem.sc.edu1. (1) Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St, Columbia, SC 29208, (2) NanoCenter, University of South Carolina, Columbia, SC 29208
A series of calcium bismuth oxides was synthesized and assayed for photocatalytic activity against a Bi2O3 standard. All oxides were visibly colored, with band edges falling in the 400nm-500nm region. A family of potential substrates (1-adamantol, benzanilide, diethyl phthalate, diphenylamine, and 2,4,6-trimethylphenol,) were photodegraded in aqueous, 0.03 wt% suspensions of the photocatalysts. A Suntest XLS+ system (Xe lamp) was used to illuminate the suspensions. Substrate degradation was followed using liquid-liquid extraction followed by GC-MS techniques. Generically, photocatalytic oxidation increased with increasing Ca/Bi ratio, with Ca6Bi6O15 being the most effective photocatalyst at an equal wt% loading. The observed rates of photocatalytic degradation (fastest to slowest for Ca6Bi6O15) ranked: 2,4,6-trimethylphenol > diphenylamine > benzanilide > diethyl phthalate > 1-adamantol. The photostabilities of the catalysts are also reported, and the effects of common photocatalyst poisons (bicarbonate, sulfate, dissolved organic matter) discussed.