Photodegradation of bisphenol A by highly stable palladium-doped mesoporous graphite carbon nitride (Pd/mpg-C3N4) under simulated solar light irradiation

Palladium modified mesoporous graphitic carbon nitride polymer (Pd/mpg-C3N4) was fabricated and used for the degradation of bisphenol A (BPA) in water. Doping Pd on the surface of mpg-C3N4 enhanced the light absorbance in the range of UV-vis region. Most of the embedded Pd was present as Pd-0 and could act as electron traps and facilitate the separation of photogenerated holes and electron pairs. As a result, the photocatalytic performance was improved significantly. The reaction rate constant (k(obs)) increased with the Pd loading on the surface of mpg-C3N4 and the maximum was achieved with 1.50% Pd. Almost 100% of BPA (20 mg L-1) was photodegraded by the solids of 0.5 g L-1 Pd/mpg-C3N4 after irradiation with simulated solar light for 360 min. The Pd/mpg-C3N4 exhibited very stable and high efficient photocatalytic activity to BPA in a wide range of pH 3.08-11.00. It also displayed high photocatalytic activity without photocorrosion after reuse for many times. Hydroxyl radicals, photogenerated holes, and superoxide radical species were responsible for the photodegradation while the superoxide radical species were more predominant in the Pd/mpg-C3N4 reaction system. (c) 2013 Elsevier B.V. All rights reserved.