Synthesis, characterizations, and photocatalytic activity of ZnO/NiBi2O4

Abstract

ZnO/NiBi2O4 was successfully synthesized using patikan kebo leaf extract (PKLE) in a two-phase system. The band gap value of ZnO/NiBi2O4 was 2.72 eV, which is actively in the visible region. The photocatalytic activity of ZnO/NiBi2O4 showed better degradation of malachite green than that of ZnO and NiBi2O4. The degradation efficiency over ZnO/NiBi2O4, NiBi2O4, and ZnO were 92.30 %, 77.33 %, and 55.99 %, respectively, under visible light for 120 min. The reaction rate constant using ZnO/NiBi2O4 was greater than that of ZnO and NiBi2O4, suggesting that the modification of ZnO with NiBi2O4 increased the photodegradation activity by hindering the photorecombination of electron-holes in ZnO. Notably, O2∙–, ∙OH, and h+ are identified as crucial species that play a vital role in the degradation process confirmed by reactive oxygen species (ROS) analysis. This work studied potential ZnO/NiBi2O4 materials for photocatalytic dye degradation applications.