Preparation and characterization of SrTiO3-Ag/AgCl hybrid composite with promoted plasmonic visible light excited photocatalysis

Abstract

An efficient visible light responsive photocatalyst hybrid composite SrTiO3-Ag/AgCl was prepared via hydrothermal method and subsequent chemical precipitation/in-situ photoreduction at room temperature. The phase structure, morphology, element mapping distribution, surface chemical composition, specific surface area, and light absorption ability of the samples were characterized. The transient photocurrent response and electrochemical impedance under visible light illumination indicate that SrTiO3-Ag/AgCl composite possesses a more intense photocurrent response and a smaller surface resistance than SrTiO3 and Ag/AgCl due to the lower electrons-holes recombination. SrTiO3-Ag/AgCl composite exhibits an obvious promoted visible light excited photovcatalytic activity in photodecomposition of methyl orange, rhodamine B and phenol, compared to SrTiO3 and Ag/AgCl. A possible photocatalytic mechanism was proposed, indicating that the synergistic effect of surface plasmonic resonance of Ag0 photoreduced from AgCl and decreased the recombination rate of photogenerated carriers through transferring electrons from the surface of Ag0 to SrTiO3 promote the excellent photocatalytic activity of SrTiO3-Ag/AgCl. Moreover, the photodegradation reaction process of methyl orange, rhodamine B and phenol on SrTiO3-Ag/AgCl follows the pseudo-first-order kinetic model, and the reaction rate constants are approximately 10 times greater than those on Ag/AgCl. Four-recycling photocatalytic process of methyl orange on SrTiO3-Ag/AgCl also indicates a superior stability and durability.