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

Abstract

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-Fe2O3-PDAAQ@BiVO4. With the concerted efforts of the ternary structure, the photocurrent of γ-Fe2O3-PDAAQ@BiVO4 photoanode reach to 5.35 mAcm2 at 1.23 VRHE (3.3 times of pure BiVO4). The improvement is ascribable to the abundant catalytic active sites and large catalytic area of γ-Fe2O3 nanoparticles. Additionally, theoretical calculations show that PDAAQ can form type II heterojunction with BiVO4 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.