Periodic Micropillar‐Patterned FTO/BiVO4 with Superior Light Absorption and Separation Efficiency for Efficient PEC Performance

Abstract In this study, a high‐performance photoanode based on 3D periodic, micropillar‐structured fluorine‐doped tin oxide (FTO‐MP) deposited with BiVO 4 is fabricated using the patterned FTO by direct printing and spray pyrolysis, followed by the deposition of BiVO 4 by sputtering and V ion heat‐treatment on the patterned FTO. The FTO‐MP enables light scattering owing to its 3D periodic structure and increases the light absorption efficiency. In addition, the high electron mobility of FTO and enlarged surface area of FTO‐MP enhance the separation efficiency. Due to the combination of these enhancing strategies, the photocurrent density of micropillar‐patterned BiVO 4 at 1.23 V RHE reached 2.97 mA cm −2 , which is 67.8% higher than that of flat BiVO 4 . The results suggest that the efficiency can increase significantly using the patterned FTO fabricated by an inexpensive and simple process (i.e., direct printing and spray pyrolysis), thereby indicating a new strategy for the enhancement of efficiency in various energy fields.