Metal-Organic Framework-Derived p-Cu2O/n-Ce-Fe2O3 Heterojunction Nanorod Photoanode Coupling with a FeOOH Cocatalyst for High-Performance Photoelectrochemical Water Oxidation

Juan Wu; Pan Huang; Huitao Fan; Gang Wang; Weisheng Liu

doi:10.1021/acsami.0c03929

Metal-Organic Framework-Derived p-Cu₂O/n-Ce-Fe₂O₃ Heterojunction Nanorod Photoanode Coupling with a FeOOH Cocatalyst for High-Performance Photoelectrochemical Water Oxidation

ACS Appl Mater Interfaces. 2020 Jul 8;12(27):30304-30312. doi: 10.1021/acsami.0c03929. Epub 2020 Jun 25.

Authors

Juan Wu¹, Pan Huang¹, Huitao Fan¹, Gang Wang¹, Weisheng Liu¹

Affiliation

¹ 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: 32543170
DOI: 10.1021/acsami.0c03929

Abstract

Rapid charge recombination and slow water oxidation kinetics are key drawbacks that limit the photoelectrochemical water splitting efficiency of Fe₂O₃. In this work, we designed and fabricated for the first time that a metal-organic framework (MOF)-derived p-Cu₂O/n-Ce-Fe₂O₃ nanorod array photoanode for the photogenerated charge effectively separated and transported at the Cu₂O/Ce-Fe₂O₃ p-n heterojunction interface through a built-in electric field. In addition, the MOF-derived porous Cu₂O nanoparticles have a large surface area, and thus, can offer more surface active sites for water oxidation. As anticipated, the novel structure Cu₂O/Ce-Fe₂O₃ photoanode showed superior photocurrent density (3.2 mA cm^-2), excellent bulk charge separation efficiency (38.4%), and surface charge separation efficiency (77.2%). After further modification with the FeOOH cocatalyst, the photocurrent density of the FeOOH/Cu₂O/Ce-Fe₂O₃ photoanode reached 4.2 mA cm^-2 at 1.23 V_RHE (V vs reversible hydrogen electrode), having a low onset potential of 0.63 V_RHE.

Keywords: Ce-doping; HKUST-1(MOF)-derived Cu2O nanoparticles; hematite; photoelectrochemical water splitting; p−n heterojunction.