Multifunctional polymer coating cooperated with γ-Fe2O3 for boosting photoelectrochemical water oxidation

Modifying semiconductor photoanode with efficient and cheap iron-based oxygen evolution cocatalyst along with functional interlayer is an efficient method to enhance the water splitting efficiency of photoelectrochemical (PEC). Poly-aminoanthraquinone (PDAAQ) due to its outstanding reversible redox activity plays a significant role as proton receptor. Herein, an easy-handle solvothermal method is adopted to prepare γ-Fe 2 O 3 -PDAAQ@BiVO 4 . With the concerted efforts of the ternary structure, the photocurrent of γ-Fe 2 O 3 -PDAAQ@BiVO 4 photoanode reach to 5.35 mAcm 2 at 1.23 V RHE (3.3 times of pure BiVO 4 ). The improvement is ascribable to the abundant catalytic active sites and large catalytic area of γ-Fe 2 O 3 nanoparticles . Additionally, theoretical calculations show that PDAAQ can form type II heterojunction with BiVO 4 to inhibit carrier recombination. At the same time, the role of PDAAQ in promoting water oxidation kinetics by accelerating proton coupled electron transfer process has also been confirmed in isotope effect experiment.