Hybrid Ce-Fe2O3/ZIF-67 Photoanode with Efficient Photoelectrochemical Water Oxidation Performance

Juan Wu; Jin Liu; Lin Jin; Bin Hu; Weisheng Liu

doi:10.1021/acs.inorgchem.2c01491

Hybrid Ce-Fe₂O₃/ZIF-67 Photoanode with Efficient Photoelectrochemical Water Oxidation Performance

Inorg Chem. 2022 Aug 15;61(32):12591-12598. doi: 10.1021/acs.inorgchem.2c01491. Epub 2022 Aug 3.

Authors

Juan Wu^{1

2}, Jin Liu¹, Lin Jin¹, Bin Hu¹, Weisheng Liu²

Affiliations

¹ Henan Key Laboratory of Rare Earth Functional Materials, International Joint Research Laboratory for Biomedical Nanomaterials of Henan, Zhoukou Normal University, Zhoukou 466001, P. R. China.
² Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.

PMID: 35920803
DOI: 10.1021/acs.inorgchem.2c01491

Abstract

Surface states and slow water oxidation kinetics greatly limit the photoelectrochemical (PEC) water oxidation performance of Fe₂O₃. To solve the above problems, coupling Fe₂O₃ with a passivation layer and an oxygen evolution cocatalyst, respectively, is the common method. Though this method may improve its PEC performance, this also results in a low charge-transfer efficiency caused by the interface resistance between Fe₂O₃ and the modification materials (passivation layer and oxygen evolution cocatalyst). Therefore, it is important to identify a multifunctional modifier material to reduce the interfacial resistance due to the presence of multiple different materials. In this work, we introduced a thin cobalt-based metal-organic framework layer (ZIF-67) as a dual-functional material that acted as both a passivation layer and a water oxidation cocatalyst for a photoanode based on Ce-Fe₂O₃ nanorod arrays. The ZIF-67 layer inhibited charge carrier recombination by passivating the surface states. The PEC performance was improved due to the rich Co²⁺ photogenerated hole-capture sites, which facilitated charge transfer and separation. As expected, the Ce-Fe₂O₃/ZIF-67 photoanode exhibited superior water oxidation performance, with a photocurrent of 2.07 mA cm^-2 at 1.23 V_RHE, which is 1.74 times higher than that of the Ce-Fe₂O₃ photoanode. The onset potential was negatively shifted by 71 mV. This study provides basic insights and a strategy for reducing interfacial resistance in hybrid materials.