Surface plasmon resonance metal-coupled biomass carbon modified TiO2 nanorods for photoelectrochemical water splitting

Abstract

Exploring efficient and stable photoanode materials is a necessary link to realize the practical application of solar-driven photoelectrochemical (PEC) water splitting. Hence, we prepared rutile TiO 2 nanorods, with a width of 50 nm, which was growth in situ on carbon cloth (TiO 2 @CC) by hydrothermal reaction. And then, Ag nanoparticles (NPs) and biomass N,S-C NPs were chosen for the additional modification of the fabricated TiO 2 nanorods to produce broccoli-like Ag-N,S-C/TiO 2 @CC nanocomposites. According to the result of ultraviolet–visible diffuse reflectance spectroscopy (UV–vis) and PEC water splitting performance tests, Ag-N,S-C/TiO 2 @CC broadens the absorption region of TiO 2 @CC from the ultraviolet region to the visible region. Under AM 1.5G solar light irradiation, the photocurrent density of Ag-N,S-C/TiO 2 @CC is 89.8 μA·cm −2 , which is 11.8 times higher than TiO 2 @CC. Under visible light irradiation, the photocurrent density of Ag-N,S-C/TiO 2 @CC reaches to 12.6 μA·cm −2 , which is 21.0 times higher than TiO 2 @CC. Moreover, Ag-N,S-C/TiO 2 @CC shows a photocurrent responses in full pH range. It can be found that Ag NPs and N, S-C NPs play key roles in broaden the absorption range of TiO 2 nanorods to the visible light region and, promote the occurrence of PEC water oxidation reaction due to the surface plasmon resonance effect of Ag NPs and the synergistic effect of N,S-C NPs. The mechanism demonstrated that Ag-N,S-C/TiO 2 @CC can separate the photogenerated electron-hole pairs effectively and transfer the photogenerated electrons to the photocathode (Pt plate) in time. This research provides a new strategy for exploration surface plasma metal coupled biomass carbon materials in the field of PEC water splitting.