Photosensitive polymer and semiconductors bridged by Au plasmon for photoelectrochemical water splitting

•A synthesized photoelectrode TiO2/Au/PTh was applied in photoelectrochemical water splitting and provided H2 production rate for the first time.•Au nanoparticles play a role as both cocatalyst and electronic transmission carrier, because of its Plasmon effect and electronic transmission capability.•Many results like photoelectric response, conversion efficiency, photovoltage decay and so on have effectively prove the advantage of the ternary structure.

Heterogeneous semiconductor has received increasing attention as promising photoelectrode matrix in photoelectrochemical (PEC) water splitting. However, the composition and optimization of heterostructure still limited the photoelectric transformation and PEC water splitting efficiencies. Here, an effective strategy was introduced to enhance PEC performance by sandwiching Au plasmon inside inorganic-organic hybrid heterostructure. We successfully fabricated TiO2 and polythiophene (PTh) heterostructure bridged by Au nanoparticles, and applied it in PEC water splitting for the first time. Compared with traditional TiO2 and TiO2/PTh, the as-prepared heterostructure photoelectrode exhibited the optimal photoelectric conversion (0.11%, at 0.22 V vs Ag/AgCl) and PEC hydrogen production rate (2.929 mmol h−1 m−2, at 50 mW/cm2 and 0.4 V vs Ag/AgCl). The enhanced water splitting can be mainly contributed to the transparent PTh nanowires as the photosensitizer and Au nanoparticles as both electron-transport bridge and plasmonic sites.

Graphical abstractThe synthesized TiO2/Au/PTh photoelectrode, increasing the absorption of visible light and promoting the electron transfer between organic polymer and inorganic material, could be enhanced the effect of light conversion efficiency and photoelectrocatalysis for hydrogen production.Figure optionsDownload full-size imageDownload as PowerPoint slide