Synthesis of aluminum alloy (AA) based composites TiO2/Al5083 and porphyrin/TiO2/Al5083: Novel photocatalysts for water remediation in visible region

Abstract

Al5083 is an aluminium alloy with magnesium and traces of manganese and chromium. It is exceedingly resistant to attack by seawater and manufacturing chemicals. In this work, the synthesis of aluminium alloy (AA) based composites TiO2/Al5083 and Porphyrin/TiO2/Al5083 (Porphyrin = Tetrakis(4-carboxyphenyl) porphyrin (TCPP)) has been reported. We employed a chemical etching approach to activate the surface of AA. After the etching process, we successfully coated the TiO2 substrate on the Al5083 surface. In order to investigate the role of TiO2 thickness on photocatalytic efficiency, one, two and three layers of TiO2 were deposited on AA surface and three composites TCPP/TiO2(1)/Al5083, TCPP/TiO2(2)/Al5083 and TCPP/TiO2(3)/Al5083 were produced. We used these AA-composites as the new photocatalysts for degradation of the organic chloride Rhodamine B (RhB) under visible light irradiation. The role of porphyrin sensitizer in the photocatalytic degradation of RhB was investigated as well. The results showed that employing TCPP as a photosensitizer caused the redshift in TiO2/Al5083 absorption spectra reinforcing the photodegradation of RhB. Moreover, TCPP/TiO2(3)/Al5083 composite with three-layers of TiO2 has the highest performance with 29.19 percent of photodegradation efficiency in the visible region.