Efficient Photodegradation of Organic Pollutants By Using a Bi2CuO4/BiPO4 Heterojunction Photocatalyst

Abstract

AbstractPhotocatalysis is the most promising and cheap route for water purification. In this work, we demonstrate the degradation of organic pollutants, such as picric acid and methylene blue, by an efficient, reusable Bi2CuO4/BiPO4 heterojunction photocatalyst. The Bi2CuO4/BiPO4 heterojunction was fabricated using a solvothermal method followed by sonication. The Bi2CuO4/BiPO4 heterojunction shows enhanced photocatalytic degradation of picric acid and methylene blue dye under ultraviolet‐visible (UV/Vis) light compared to its individual constituents as well as compared to the previously reported Bi2CuO4‐based photocatalyst. The high photocatalytic activity of the Bi2CuO4/BiPO4 heterojunction can be attributed to the enhanced separation efficiency of the photogenerated electron and hole pairs. The photocatalytic activity of the Bi2CuO4 nanostructures, which is generally weak due to faster recombination of the electron and hole, is enhanced by means of heterojunction formation with BiPO4 nanocrystals. Interestingly, the hydroxyl radical, which was found to be the primary active species, is not generated at the valence band due to thermodynamic constraints. In contrast, experiments carried out under controlled conditions unequivocally confirm that their generation is related to oxygen reduction at the conduction band.