Defective TiO2 composite photoanodes with surface-modified Prussian blue for efficient photoelectrochemical water splitting†
Abstract
Solar hydrogen production has garnered significant attention in addressing the energy crisis due to its efficient and environmentally friendly nature. In this study, we successfully used a simple electrochemical reduction method to introduce oxygen vacancies on a TiO2 nanorod photoanode, termed defective TiO2 (D-TiO2). Meanwhile, Prussian blue (PB) was deposited on D-TiO2 to create a core–shell composite photoanode material. By optimizing the reduction time, the charge separation of D-TiO2 is improved. The addition of PB resulted in the formation of a II-type heterojunction between TiO2 and PB. The formation of the heterojunction enlarges the light absorption range of TiO2, increases the active sites, and reduces the recombination of photogenerated charges due to the large surface area of PB. The photocurrent density of D-TiO2@PB reaches 2.10 mA cm−2 at 1.23 V vs. RHE, with an enhanced IPCE of 35.8%.