Photocatalytic Application of Ag-Decorated CuS/BaTiO3 Composite Photocatalysts for Degrading RhB

Herein, binary CuS/BTO and ternary CuS/Ag/BTO composite photocatalysts have been fabricated by anchoring CuS and Ag nanoparticles onto BaTiO3 (BTO) polyhedra. The as-prepared composite photocatalysts were characterized by means of the techniques of transmission/scanning electron microscopy, x-ray powder diffraction, ultraviolet–visible diffuse reflectance spectroscopy, x-ray photoelectron spectroscopy and photoluminescence spectroscopy. Transient photocurrent and electrochemical impedance spectroscopy measurements suggest that the ternary 5%CuS/(1%Ag/BTO) composite possesses the highest separation efficiency of electron/hole pairs. The photodegradation experiments were conducted by using simulated sunlight as the light source to decompose Rhodamine B in water solution. The 5%CuS/(1%Ag/BTO) and 5%CuS/BTO composites are demonstrated to have the highest and second highest photodegradation activity, respectively. As compared with that of bare BaTiO3 and CuS, the photoactivity of 5%CuS/(1%Ag/BTO) is increased to 3.3 and 2.0 times, respectively. The electron/hole separation mechanism and the role of localized surface plasmon resonance of Ag nanoparticles in the dye photodegradaton were systematically investigated.