MWNT–TiO2:Ni composite catalyst: A new class of catalyst for photocatalytic H2 evolution from water under visible light illumination

Multi-walled carbon nanotube, TiO2 and Ni composite catalysts (MWNT–TiO2:Ni) were prepared by a modified chemical vapor deposition. The nanoscaled composite materials were extensively characterized by TG, SEM, Raman and UV–vis spectra. The photoactivity of the catalyst for H2 evolution was investigated in the presence of methanol sacrificial reagent under visible light illumination. The rate of H2 evolution was 38.1 μmol/h at a weight ratio of MWNT/TiO2 equal to 4.4%. The experimental results were rationalized by assuming that MWNTs serve as photosensitizer, synergetic with metallic Ni, greatly enhancing the activity of visible light-responsive photocatalyst.