Efficient photoelectrochemical water-splitting over carbon membrane linked Au and TiO2 nanotube arrays film based on multiple carriers transport paths

Abstract

Herein, a carbon membrane and Au nanoparticles were combined to improve the efficiency of photoelectrocatalytic water splitting over a TiO2 nanotube arrays film (TiO2 NTAF). Two different ternary nanostructures were constructed by hydrothermal and photochemical deposition processes. One was carbon membrane bridged Au nanoparticles and TiO2 nanotube arrays (Au/C/TiO2 NTAF), while the other was Au nanoparticles sandwiched between carbon membrane and TiO2 nanotube arrays (C/Au/TiO2 NTAF). The two structures exhibited enhanced visible light harvesting ability, but they showed distinctly different photoelectric properties. The unique microstructure of C/Au/TiO2 NTAF resulted in a much higher reduction of the electron cloud density of Au nanoparticles as carrier recombination centers, which were responsible for its poor photoelectrochemical performance. However, a champion photocurrent of Au/C/TiO2 NTAF was observed (0.984 mA cm−2), indicating superior ability of the photoelectrocatalytic water splitting. The great enhancement was attributed to multiple carriers transport paths, which can efficiently utilize the sensitization of the carbon membrane and the surface plasmon resonance effect of the Au nanoparticles.