Lightweight 3D-TiO2 Nanotube Arrays on Ti Mesh for Promoted Photoelectrochemical Water Splitting

Lightweight 3D-TiO2 nanotube arrays are successfully prepared via a simple anodization method. The lightweight 3D-TiO2 nanotube arrays yield a photocurrent density of 0.57 mA/cm2 at 0.22 Vvs. Ag/AgCl with Faradic efficiency of 100%, which is 1.9 times larger than that of 2D-TiO2 NTAs. The boosted performance is attributed to 3D arrays, which not only can effectively absorb the incident, reflected and/or refracted light from any direction surrounding the wire, but also provide larger surface areas of electrode/electrolyte junction. Moreover, the underlying Ti mesh serves as a direct channel for the rapid photoelectron-hole transport during the PEC water splitting process. This work offers a contribution to the practical applications of TiO2 nanotube-based photoanodes.