An effective Ni/C co-catalyst for promoting photocatalytic hydrogen evolution over TiO2 nanospheres

Ni/C/TiO 2 nanocomposites have been prepared by base-catalyzed hydrolysis of tetrabutyl titanate in the Ni/C suspension and subsequent heat treatment at different temperatures. The Ni/C co-catalyst was fabricated by salt-templated pyrolysis of a nickel oleate complex. Phase and morphological analyses revealed that the Ni/C/TiO 2 nanocomposites were largely composed of anatase TiO 2 nanospheres. Hydrogen evolution measurements showed that the photocatalytic activity of TiO 2 nanospheres was improved by the Ni/C co-catalyst under simulated sunlight. The best-performing Ni/C/TiO 2 -T700 achieved a H 2 evolution rate of 1745.0 μmol h -1 g -1 , which was 9-fold as high as pure TiO 2 (185.0 μmol h -1 g -1 ). Based on optical, electrochemical, and photo-electrochemical results, the enhanced catalytic activity could be attributed to the Ni/C co-catalyst promoting the photo-generated charge separation and suppressing the electron-hole pair recombination. This work provides an alternative type of Ni-based co-catalyst for enhancing the hydrogen evolution activity of TiO 2 -based photocatalysts.