Photocatalytic degradation of fast green using nanosized CeCrO₃

Abstract

Fast green dye has been widely used in histology and cytology. It has been found to have tumorigenic effects in experimental animals, as well as mutagenic effects in both experimental animals and humans. Furthermore, in its undiluted form it poses risks of irritation of eyes, skin, digestive tract, and respiratory tract. For photocatalytic degradation of fast green dye the nano-sized bimetal ternary oxide (CeCrO3) ultrafine powder has been prepared using microwave treatment. It has been characterized by XRD and SEM. The photocatalytic degradation of fast green dye was measured by visible absorption spectroscopy. To obtain the optimal conditions for the dye degradation, the effect of various experimental parameters, i.e. pH, amount of photocatalyst, concentration of dye and light intensity on the rate of reaction was studied. A tentative mechanism for the photocatalytic degradation of fast green was proposed. Photocatalytic degradation of fast green dye followed a pseudo first-order kinetics. It was found that the dye degradation gave the best results at a pH of 7.5, and using a 70 mW·cm–2 light intensity with 0.05 g of nano-sized CeCrO3. At room temperature, the photocatalytic degradation rate constant of fast green dye was k = 4.41·10–4 s–1.

Keywords

• photocatalytic degradation
• fast green
• nanosized cecro3
• visible absorption spectrometry