TiO2@PCN core-shell nanoarrays decorated with Au nanoparticles for enhanced photoelectrochemical performance.

• We designed a convenient route to fabricate the ternary Au/TiO 2 @PCN photoanode. • The Au/TiO 2 @PCN remarkably facilitated the interfacial charge transfer and separation process. • The Au/TiO 2 @PCN presents a pronounced photocurrent density of 2.03 mA cm−2 (1.23 V vs. RHE). • The PEC performance of Au/TiO 2 @PCN can be enhanced both in UV and visible light region. Utilization of solar energy to split water via photoelectrochemical (PEC) technique is a desirable technology to address the development of sustainable carbon-free energy source. The key challenge of this advanced technique is to design a photoelectrode with both high solar to chemical efficiency and fast charge transfer and separation efficiency. Herein, the core-shell heterostructure of TiO 2 @PCN (P doped g -C 3 N 4) decorating with Au nanoparticles (Au NPs) photoanode (Au/TiO 2 @PCN) is successfully fabricated for high-efficiency PEC water splitting. The resulting integrated Au/TiO 2 @PCN photoanode exhibits significantly enhanced PEC activities both in UV and visible light region with AM 1.5 G irradiation (100 mW cm−2). Each component of Au/TiO 2 @PCN plays a vital role in promoting the PEC performance. The TiO 2 @PCN core-shell heterostructure could remarkably facilitate the charge transfer and separation efficiency with the effect of an internal built-in electric field. The introduction of Au NPs could further enhance the charge transfer efficiency and improve the PEC activity of TiO 2 @PCN in visible light, which is attributed to the localized surface plasmon resonance (LSPR) effect. Accordingly, the Au/TiO 2 @PCN presents pronounced photocurrent density of 2.03 mA cm−2 (1.23 V vs. RHE), which is four-fold higher than that of TiO 2 NRs (0.51 mA cm−2). This work supports a new approach to combine the advantages of the core-shell heterostructure and the LSPR effect of noble metal for high-performance PEC water oxidation. [Display omitted] [ABSTRACT FROM AUTHOR]