Uncovering the influence of Ni-doping in CuBi2O4 photocatalyst on its visible-light-responsiveness for the efficient removal of toxic Alizarin yellow R dye from wastewater

Abstract

In recent years, wastewater pollution has a significant huge impact on both human life and aquatic animals. Wastewater treatment has become a challenging task for researchers due to the presence of complex organic pollutants. In the present work, we report the investigation of the influence of Ni-doping on photocatalytic activity of CuBi2O4 to effectively removal of complex organic pollutants. For this, we synthesized the various photocatalysts, including CuBi2O4, Ni0.05Cu0.95Bi2O4, Ni0.10Cu0.90Bi2O4, and Ni0.15Cu0.85Bi2O4 using a facile hydrothermal method. The photocatalytic efficiency of the synthesized photocatalysts was evaluated for degradation of Alizarin yellow R (AYR) dye under visible-light illumination. The experimental results revealed an 85.78% degradation of AYR dye in the presence of a CuBi2O4 photocatalyst. In constrast, the degradation rate increased to 98.43% for Ni0.10Cu0.90Bi2O4 photocatalyst within 70 min. Similarly, the rate constant also increased from 0.0286 min−1 to 0.0633 min−1, affirming the photocatalytic efficacy of the Ni0.10Cu0.90Bi2O4 photocatalyst. The increased photocatalytic efficiency of the Ni0.10Cu0.90Bi2O4 photocatalyst was attributed to its increased surface area (98.27 m2 g−1) and reduced the optical bandgap energy due to the incorporation of Ni metal ions into the basic framework of CuBi2O4. Furthermore, the investigation into the effect of various reaction parameters revealed a significant influence on the removal of AYR dye. It can be perceived that the formation of •OH and O2•− radicals on the surface of the catalyst resulted in the degradation of AYR. Notably, the synthesized Ni0.10Cu0.90Bi2O4 photocatalyst displayed exceptional photostability. This work provides a cost-effective method of developing efficient photocatalyst for wastewater remediation.