Effect of Ti foil size on the micro sizes of anodic TiO2 nanotube array and photoelectrochemical water splitting performance

Anodic TiO2 nanotube (NT) array is promising for the flexible and efficient photoanode in photoelectrochemical water splitting (PECWS) cell. However, photocurrent response of pristine anodic NT literature has a ca 50 times difference, viz. from 0.05 to 1 mA/cm2. Improvement base achieving high anode. Here, we examine size effect different scale on PECWS performance with manipulating macro Ti foil. With decrease foil 6 cm2, corresponding growth active area 3.45 0.65 increased by 50.6%, 1.13 mA/cm2 at 1.23 VRHE (V versus reversible hydrogen electrode). The also significantly influences micro sizes nanotubes including crystallite size, double wall thickness, inner diameter tube length, which have profound effects WS efficiency. relationships between involved length scales, span six orders magnitude ten nanometers (10?8 m) centimeter (10?2 m), efficiency analyzed discussed. Transient i-t curves are used represent chemical kinetics during array. Finally, photon capture scheme proposed explain physics behind multi photoanode. need quantitative models scale-up process stressed.