Synthesis and photoelectrochemical properties of tungsten oxide arrays with a snowflake-like hierarchical structure.

[Display omitted] • Well-aligned WO 3 arrays on FTO substrate were fabricated by hydrothermal process. • The obtained WO 3 arrays consist of snowflake-like hierarchical structures. • The (0 2 0) plane of the WO 3 array is perpendicular to the FTO substrate. • An impressive photocurrent density of 2.43 mA·cm−2 at 1.23 V vs RHE was obtained. • The performance is attributed to its structure and orientation of crystal planes. In this study, we successfully fabricated well-aligned WO 3 snowflake-like hierarchical arrays (SHAs) with (0 2 0) facet perpendicular to FTO substrate. The fabricated samples were characterized by XRD, SEM, and UV–vis. The SHA photoanode exhibited an impressive photocurrent density of 2.43 mA·cm−2 at 1.23 V vs RHE, which is 1.76 times higher than the sandwich-like structures (SSs). This improved performance can be attributed to the special SHAs and the preferred orientation, which would effectively promote the separation and transfer of carriers. [ABSTRACT FROM AUTHOR]