A highly active nano-micro hybrid derived from Cu-bridged TiO2/porphyrin for enhanced photocatalytic hydrogen production

摘要

Development of photocatalysts with high activity and durability for hydrogen generation is extremely desired but still remains a great challenge currently. With Cu nanoparticles (Cu NPs) as a linker between TiO2 microsphere (TiO2 MS) and 5, 10, 15, 20-meso-tetra(4-carboxyphenyl)porphyrin (TCPP), a novel nano-micro hybrid (TiO2 MS-Cu-TCPP) was prepared via a facile method. By bridging TiO2 MS and TCPP with Cu NPs, the absorption and the electron transfer of TiO2 MS were greatly improved. When the TiO2 MS-Cu-TCPP was employed as the photocatalyst for hydrogen evolution, it exhibited higher activity and stability than those of the TiO2 MS, the TiO2 MS-Cu and the TiO2 MS-TCPP, TiO2 MS-Cu-CuTCPP and TiO2 MS-TCPP-Cu. The photocatalytic activity was enhanced for about 6 times with respect to that of the pristine TiO2 MS. The excellent performance for the nano-micro hybrid can be attributed to wide light absorption, more reactive sites, and facilitated interfacial electron transfer owing to the strong interaction between TiO2 and TCPP with Cu NPs as the linker and cocatalyst. Subsequently, a high and stable photocatalytic activity over the TiO2 MS-Cu-TCPP nano-micro hybrid was achieved, demonstrating the importance of interfacial modification to a semiconductor photocatalyst. This result gives us a new perspective of constructing special structures for efficient light utilization and electron transfer.