Preparation of TiO2@Sn(Sb)O2 core–shell composites and their applications for electrocatalytic degradation of methylene blue

TiO 2 @Sn(Sb)O 2 core–shell composites (TiO 2 @SnO 2 , TiO 2 @Sb 2 O 4 and TiO 2 @Sb-SnO 2 ) have been prepared through a chemical co-precipitation method with a calcination process. The mixture hydrolysates of SnCl 4 and SbCl 3 have been deposited on the surface of TiO 2 as the precursor. These hydrolysates have been converted to Sn(Sb)O 2 particles, leading to the formation of the TiO 2 @Sn(Sb)O 2 core–shell structure. Their electrochemical performances and electrocatalytic degradation efficiencies of methylene blue (MB) have been investigated. It is found that TiO 2 @Sb-SnO 2 electrode presents a larger effective electrocatalytic area and more electroactive sites, which provide more contact points between the pollutant and electrode and enhance electrocatalytic oxidation activity. The TiO 2 @Sb-SnO 2 electrode exhibits a higher degradation efficiency (97.6%) than that of TiO 2 @SnO 2 (80.1%) and TiO 2 @Sb 2 O 4 (34.9%). The TiO 2 @Sb-SnO 2 electrode provides a 91.1% degradation efficiency after five cycles test, indicating a high stability during degradation process. These results show that the as-prepared TiO 2 @Sb-SnO 2 electrode can provide a promising application to treat dye wastewater, which relies on its core–shell structure.