Highly efficient hydrogen production via water splitting using Pt@MWNT/TiO2 ternary hybrid composite as a catalyst under UV–visible light

Platinum nanoparticles (Pt)-supported multi-walled carbon nanotube (MWNT)/titanium dioxide (TiO2) ternary composite was synthesized by a step-wise approach. The MWNT/TiO2 composite was prepared via a sol–gel technique, after which post annealing was applied, and then the Pt nanoparticles were loaded by photo-deposition. This paper reports the enhanced hydrogen production through the application of Pt nanoparticles on photocatalytic water splitting under visible and UV–vis light. The results showed that no appreciable H2 production was achieved using Pt@MWNT/TiO2 ternary composites as a photocatalyst under visible light, whereas a substantial amount of H2 was produced under full spectra. The ternary composite with a Pt loading of 1.5 wt% exhibited the highest H2 production level (435.9 μmol h−1), which was significantly higher than that of pure TiO2 (78.6 μmol h−1) and MWNT/TiO2 composite (235.6 μmol h−1). The efficient hydrogen production activity of the ternary composite can be attributed to the synergetic effect of MWNT and Pt nanoparticles, which enhances the light absorption ability and facilitates a greater charge separation activity. Hence, we report that the appropriate combination of Pt as a co-catalyst can greatly improve the photocatalytic H2 production performance of MWNT/TiO2 composites.