Highly efficient visible light photoelectrochemical degradation of ciprofloxacin and azo dyes by novel TiO₂/AgBiS₂ photoelectrocatalyst

Nanocomposites have proven to own outstanding visible light photoelectrochemical characteristics. Ternary chalcogenides (TC), with narrow bandgaps and efficient visible light absorption, are regarded as excellent components in forming nanocomposites with classic semiconductors such as TiO₂. In the current study, TiO₂/AgBiS₂ binary nanocomposite was synthesized via the hydrothermal method and was successfully deposited on FTO via facile and efficient EPD technique. The XRD results showed the formation of cubic phase AgBiS₂ with coral-shaped structures over the TiO₂ anatase phase. The FESEM and mapping results illustrate successful formation of the binary nanocomposite. The UV-DRS for the nanocomposite confirms enhancement in visible light absorption and a decrease in bandgaps calculated through Tauc's equation due to the junction formation. The synthesized photoelectrode was electrochemically characterized by the EIS, LSV, and photocurrent measurements. To further study the PEC application of the material, photoelectrocatalytic degradation of CIP and MB was studied. The nanocomposite illustrated more than 65% degradation for CIP in 45 min, which considering the small amount of deposited material on the electrode, is considered an outstanding achievement. The scavenging experiments are used to propose a photoelectrocatalytic mechanism.