Sn-SnO2/C photocatalysts with visible light activity have been successfully synthesized by a simple heat-treating process using SnCl4 as precursor. The Sn-SnO2 heterojunction is built by depositing of metallic Sn on crystal lattice oxygen of as-formed SnO2, which obviously increase the amount of adsorbed oxygen on the surface of catalyst. The as-synthesized catalysts display higher photocatalytic activity than SnO2 and SnO2/C for degradation of reactive brilliant blue KN-R under visible light irradiation. The enhancement of photocatalytic performance of Sn-SnO2/C can be attributed to the formation of metallic Sn on the surface of catalysts. The metallic Sn and adsorbed oxygen as the sinks of photoinduced electron and electronic scavenges, respectively, hinder the recombination of photoexcitated electron-hole pairs, sequentially enhance the photocatalytic activity. Furthermore, a possible growth mechanism of the Sn-SnO2/C photocatalysts was proposed.
