Photocatalytic H2 generation on macro-mesoporous oxide-supported Pt nanoparticles

A series of photocatalysts were prepared with crystalline macro-mesoporous oxides and Pt nanoparticles (Pt-TiO2, Pt-Ta2O5, Pt-Nb2O5, Pt-ZrO2, and Pt-Al2O3). Transmission electron microscopy, X-ray diffraction, and N-2 adsorption-desorption isotherms reveal that the oxides have prominent macro-and mesoporosity in the crystalline walls. The high surface area and crystalline walls of the oxides play significant roles in photocatalytic H-2 production. Pt-TiO2 catalysts show enhanced photocatalytic water splitting efficiency for H-2 generation (solar energy conversion efficiency of 1.06%) under a 150 W and 1.5 AM solar simulator. Pt-Ta2O5 and Pt-Nb2O5 also generate noticeable photocatalytic activities of 0.21% and 0.16%, respectively. The enhanced photocatalytic activity is attributed to correct band alignment of the porous oxides with absorption in the UV-visible range, and ordered macro-and mesoporosity of the crystalline oxides for efficient charge transfer.