Co3O4-Bi2O3 heterojunction; An effective photocatalyst for photodegradation of rhodamine B dye

Abstract Recently, the research on development of visible-light-active photocatalysts for photodegradation of organic pollutants has got much attention. Therefore, this study reports the synthesis of Co 3 O 4 -Bi 2 O 3 heterojunction as visible-light responsive photocatalyst for photodegradation of rhodamine B dye. The Co 3 O 4 -Bi 2 O 3 heterojunction was synthesized by coprecipitation method and characterized by XRD, EDS, SEM, TGA and FTIR. The as prepared Co 3 O 4 -Bi 2 O 3 heterojunction was utilized as photocatalyst for photodegradation of rhodamine B dye using a 100 mg/L solution. It was observed that Co 3 O 4 -Bi 2 O 3 showed best catalytic performance with ~ 92% degradation of rhodamine B dye than Co 3 O 4 and Bi 2 O 3 with 14 and 34% removal of rhodamine B dye, respectively. The rate constant for Co 3 O 4 -Bi 2 O 3 catalyzed photodegradation of rhodamine B was 6 times and 3 times higher than rate constant for Co 3 O 4 catalyzed and Bi 2 O 3 catalyzed photodegradation of rhodamine B, respectively. The pH 8 was found as optimum pH for Co 3 O 4 -Bi 2 O 3 catalyzed photodegradation of rhodamine B dye.