Monodispersed Ag nanoparticles loaded on the PVP-assisted synthetic Bi ₂O₂CO₃ microspheres with enhanced photocatalytic and supercapacitive performances

Uniform 1 μm-sized Bi₂O₂CO₃ microspheres constructed by nanoplates with a thickness of about 12 nm have been obtained through a facile hydrothermal method. Ag is deposited on the surface of Bi₂O₂CO₃via a subsequent facile photoreduction process. In the synthesis process, polyvinylpyrrolidone (PVP) is used as a reactant that not only provides C and O sources but also serves as a template to induce the nanoplate-assembly to form microspheres. With the addition of KCl in the synthesis, the size of the Bi₂O ₂CO₃ microspheres can be reduced from ∼6 μm to ∼1 μm. It is demonstrated that PVP and KCl play key roles in the formation of such hierarchical microspheres. The obtained Bi₂O ₂CO₃ and novel Ag/Bi₂O₂CO ₃ composites are evaluated for photocatalytic and supercapacitive applications. The test result of the photocatalytic activity demonstrates that 0.6 wt% loading of Ag on the Bi₂O₂CO₃ microspheres exhibits significantly enhanced activity for the photodegradation of methyl orange (MO) dye, compared with Bi₂O₂CO ₃. The enhanced photocatalytic activity can be attributed to the Ag deposits acting as electron traps and the high surface area of Bi ₂O₂CO₃. Furthermore, the Ag/Bi ₂O₂CO₃ composites are primarily evaluated as supercapacitor electrodes, which deliver specific capacities of 620 and 361 F g^-1 at current densities of 1 and 5 A g^-1, respectively.