Hydrogen treatment and FeOOH overlayer: Effective approaches for enhancing the photoelectrochemical water oxidation performance of bismuth vanadate thin films
Artikel i vetenskaplig tidskrift, 2019

The water oxidation capability of the promising photoanode bismuth vanadate (BiVO4) is hampered by poor bulk electron transport and by high rates of charge recombination at the semiconductor/electrolyte interface. Here, we demonstrate that a dual modification of BiVO4 by: (i) annealing in a hydrogen-containing environment and (ii) coating with FeOOH overlayer substantially enhances the water oxidation ability of BiVO4 photoanodes. Hydrogen treated, FeOOH coated BiVO4 photoanodes exhibit a water oxidation photocurrent density of 2.16 mA cm−2 at 1.23 VRHE, which is 5 times higher than for untreated BiVO4 films. Moreover, they showed an impressive low photocurrent onset potential of −0.11 VRHE. A stable photocurrent was observed for 1 h of water oxidation measurement at 1.23 VRHE under 1 Sun illumination. The enhanced photocurrent of FeOOH/H:BiVO4 photoanode is ascribed to an improved bulk charge transport, as confirmed by impedance spectroscopy measurements and Mott-Schottky analysis. The cathodic shift of the onset potential originates from a lowering of the flat band potential and from an improvement of the charge transport at the semiconductor/electrolyte interface. The dual modification strategy used here offers a simple but effective approach of improving the water oxidation performance of BiVO4.

Hydrogen treatment

Solar hydrogen

FeOOH

Bismuth vanadate

Photoelectrochemical

Författare

Aadesh P. Singh

Chalmers, Fysik, Kemisk fysik

Indian Institute of Technology Delhi

Nishant Saini

Indian Institute of Technology Delhi

Bodh R. Mehta

Indian Institute of Technology Delhi

Anders Hellman

Chalmers, Fysik, Kemisk fysik

Beniamino Iandolo

Danmarks Tekniske Universitet (DTU)

Björn Wickman

Chalmers, Fysik, Kemisk fysik

Catalysis Today

0920-5861 (ISSN)

Vol. 321-322 87-93

Ämneskategorier

Oorganisk kemi

Materialkemi

Annan kemi

DOI

10.1016/j.cattod.2018.03.041

Mer information

Senast uppdaterat

2018-12-10