Photocatalytic H2 generation on macro-mesoporous oxide-supported Pt nanoparticles†
Abstract
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 N2 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 H2 production. Pt–TiO2 catalysts show enhanced photocatalytic water splitting efficiency for H2 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.