A facile synthesis of CuBi2O4 hierarchical dumbbell-shaped nanorod cluster: a promising photocatalyst for the degradation of caffeic acid.

The present study reports on the synthesis of Cu-bismuth oxide (CuBi2O4)-based nanorods by using a simple co-precipitation method for the photocatalytic degradation of caffeic acid (CA). The incorporation of Cu metal ions during the synthesis of CuBi2O4 nanorods might be advantageous to avoid the aggregation and control the leach out of metal ions. The calculated bandgap values of ~ 1.04, 1.02, and 0.94 eV were observed for CuBi2O4 with different amounts of Cu 1.0, 0.50, and 0.25 g, respectively. Varying the quantity of Cu metal ions easily tuned the bandgap value within the CuBi2O4-based nanorods. However, a further decrease in the bandgap value increased the recombination rate, and the less photocatalyst performance was observed. The CA degradation could be explained based on the species distribution. The CA pKa was mainly located between pKa1 and pKa2 of 4.43 and 8.6, respectively. The Cu within the CuBi2O4-based nanorods changed the electronic properties and the antibacterial ability. Therefore, the synthesized CuBi2O4-based nanorod cluster might be a promising material for the photocatalytic degradation of CA.