Facile synthesis of Co(OH)2 modified TiO2 nanocomposites with enhanced photocatalytic H2 evolution activity

•A facile precipitation route was used to prepare Co(OH)2/TiO2 nanocomposites.•The Co(OH)2/TiO2 photocatalyst has improved charge-separation efficiency.•The H2 evolution performance of Co(OH)2 modified TiO2 is significantly enhanced.

Co(OH)2 modified TiO2 (Co(OH)2/TiO2) photocatalysts were fabricated by a simple precipitation method and characterized by XRD, TEM, N2-physisorption, UV–vis DRS and PL. The photocatalytic H2 evolution performance on TiO2 was significantly enhanced by loading Co(OH)2. The optimum Co(OH)2 loading content was found to be 0.25 mol%, yielding a H2-evolution rate of 1946 μmol h−1 g−1, being about 23 times of that on pure TiO2. This enhancement of photocatalytic H2 evolution was attributed to the Co(OH)2 clusters deposited on TiO2 surface, which can act as electron traps and thus facilitate the charge carrier separation.