Plasmon enhancement on photocatalytic hydrogen production over the Z-scheme photosynthetic heterojunction system

Abstract

Direct evidence of plasmon for enhanced H2 production is observed in photocatalytic water reduction by using TiO2/WO3 electrospun nanofibers decorated with Au nanoparticles. The H2 production rate of the as-prepared composite nanofibers was greatly enhanced compared with pure TiO2 nanofibers (S0) and TiO2/WO3 nanofibers (S1). The enhanced activities were mainly attributed to the Schottky effect and Z-scheme photosynthetic heterojunction system, in this system, WO3 as a hole collector and Au as an electron collector, promoting effective charge separation. More importantly, Surface Plasmon Resonance (SPR) effect of Au further promoted charge separation and absorption of visible light. On the basis of the Z-scheme photosynthetic heterojunction system, the synergistic effect of Schottky and SPR effect further improve the performance of photocatalytic H2 production, which were directly evidenced by photocurrent, electrochemical impedance spectroscopy (EIS) and ultraviolet Photoelectron Spectrometer (UPS) analysis. Besides, the synthesis route delivered three-dimensional sheets on the basis of interwoven nanofibrous networks, which can be readily recycled for the circular application of a potent photocatalyst system.