Nickel Complexes And Carbon Dots For Efficient Light-Driven Hydrogen Production

Nitrogen-doped carbon dots were used as photosensitizers for H-2 evolution in the presence of a series of mononuclear thiosemicarbazone nickel complexes. The catalysts were designed to display different substituents at the para position of the phenyl rings. These chemical modifications tune the electron-donating abilities of the complexes and influence their capability to reduce protons into hydrogen. All photocatalytic experiments were performed in aqueous solution, using as sacrificial electron donor TCEP/Asc (1 : 1), 0.1 M each, at pH=5. The complex bearing the most electron-donating ligand with the dimethylamino (N(CH3)(2)) substituent behaves as the best catalyst in our series of photocatalytic systems with TONCAT=148, under white led radiation for 30 h. Therefore, this noble metal-free system can effectively produce hydrogen in water and further chemical modification of the ligand will likely improve its production.