Effective charge separation in site-isolated Pt-nanodot deposited PbTiO₃ nanotube arrays for enhanced photoelectrochemical water splitting

Highly uniform, self-supported PbTiO₃ nanotube arrays are fabricated on a transparent conducting glass by an all solution-based, hard-templating procedure. A new concept of site-isolation has been realized by Pt-sol infiltration only in the internal core of deposited nanotube arrays and thus physically separating electron and hole reaction sites on inside and external surface of the nanotubes, respectively. The effective charge separation by the site-isolated Pt-nanodot deposited PbTiO₃ nanotube photoanode leads to greatly enhanced photocurrent generation and H₂ evolution efficiencies relative to those of the particulate-type photoanode or PbTiO₃ nanotube without Pt infiltration in photoelectrochemical water splitting under visible light. The physical site isolation through nano-engineering of the material fabrication is expected to offer an effective strategy for preparation of high-efficiency photoelectrochemical devices.