Synthesis of Ag nanoparticles as cocatalyst onto CdSe/Al2TiO5 composite photocatalysts for enhancing photocatalytic activity

A novel plasmonic photocatalysts of Ag@CdSe/Al2TiO5 was successfully prepared via a simple and mild wet-chemical process. The physical and photophysical properties of the as-prepared Ag@CdSe/Al2TiO5 samples were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Ultraviolet-visible diffuse reflection spectroscopy (DRS), photoluminescence emission spectra (PL) and electrochemical impedance spectroscopy (EIS). The interaction between Ag@CdSe and Al2TiO5 has been characterized by X-ray photoelectron spectroscopy (XPS) analysis, and which is facile to the electron transfer between Ag@CdSe and Al2TiO5 and enhancing photocatalytic performance of Ag@CdSe/Al2TiO5 composite photocatalyst. The photocatalytic experiments demonstrat that the Ag@CdSe species can efficiently improve the separation efficiency of photoinducing electrons and holes and consequently improve the methylene blue (MB) photodegradation activity. The 20 wt% Ag@CdSe/Al2TiO5 sample exhibit the most superior photocatalytic activity. A possible photocatalytic mechanism of MB over Ag@CdSe/Al2TiO5 is proposed, which can be attributed the success to the surface plasmon resonance (SPR) effect from Ag/AgCl species.