Degradation of Abiotic Orange II Dye and Biotic E. coli by Highly Porous SiC-AgCl/Ag⁰ Photocatalyst

Abstract

An innovative procedure of producing highly porous SiC-AgCl/Ag⁰ photocatalyst were developed and tested for durability and degradability of abiotic material (azo dye, Orange II) and biotic material (bacterial, E. coli). Porous photocatalyst were made by 90% porosity silicon carbide in liquid nitrogen, coating with silver nitrate and precipitating out the non-homogeneous phase silver chloride on the surface by emerging the specimen in hydrochloride solution. SEM shows the needle-like nano sized crystal silver chloride were homogeneously crosslink on the silicon carbide backbone. Later on the specimen were heated at 200 °C for 8 h to enhance the adhesion of silver chloride and silicon carbide backbone. Through the XRD analysis under the condition of UV light irradiation, grey-black silver was generated on this porous material. Degradation of Orange II was performed under visible and UV light irradiation and the concentration degradation kinetics follow the first order reaction. Furthermore, the degradability of this photocatalyst which degrades Orange II could persist at least 4 cycles been used in our experiment with 96% degradability. Sterilization of Escherichia coli could be completed in 50 min and the degradation kinetics follows the first order reaction as well. The photocatalyst produced in this work not only reduced the cost of consuming too much silver nitrate, but increase the reliability and degradability of contaminant in the water.