Effect of Different Amounts of Pt on Fe₃O₄-TiO₂ for Photocatalytic H₂ Production Under Solar Light

In this study, Pt doped Fe3O4-TiO2 photocatalysts were synthesized in two steps; (i) Fe3O4-TiO2 (FT) was prepared by the complex-assisted vapor thermal (VT) method, (ii) Pt was doped to Fe3O4-TiO2 (FT-Pt) by the polyol method. The effect of different amounts of Pt was investigated for photocatalytic hydrogen production. The absorption spectrum of FT with 5.0 % Pt exhibits a surface plasmon resonance (SPR) peak of & SIM;420 nm which corresponds to the band gap of 2.95 eV. The FT and Pt doped FT samples showed a less intense photoluminescence (PL) band than TiO2 (T) due to the lower e(-)/h(+) recombination rate. By increasing % wt. Pt in the FT samples, PL intensity was decreased. Thus, Pt plays an essential role to hinder the recombination of e(-)/h(+) pairs. Consequently, FT-5.0 % Pt showed 144 & mu;mol/g-cat H-2 production rate, just about 3.3 times higher than that of FT photocatalyst; due to the suitable band gap energy and the retarded e(-)/h(+) recombination. Therefore, the synergistic effect of Pt and Fe3O4 is found to be beneficial to decrease the e(-)/h(+) recombination rate thus the photocatalytic activity enhancement was achieved.