AUTHOR=Dong Guofa , Xie Fengyan , Kou Fangxia , Chen Tingting , Xiao Caihong , Du Shaowu , Liang Jiaqi , Lou Chenfang , Zhuang Jiandong 

TITLE=Enhancing photoelectrochemical performance and stability of Ti-doped hematite photoanode via pentanuclear Co-based MOF modification

JOURNAL=Frontiers in Chemistry

VOLUME=12

YEAR=2024

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2024.1454524

DOI=10.3389/fchem.2024.1454524

ISSN=2296-2646

ABSTRACT=<p>Modifying photoanodes with metal-organic frameworks (MOFs) as oxygen evolution reaction (OER) cocatalysts has emerged as a promising approach to enhance the efficiency of photoelectrochemical (PEC) water oxidation. However, designing OER-active MOFs with both high photo- and electrochemical stability remains a challenge, limiting the advancement of this research. Herein, we present a facile method to fabricate a MOF-modified photoanode by directly loading a pentanuclear Co-based MOF (Co-MOF) onto the surface of a Ti-doped hematite photoanode (Ti:Fe<sub>2</sub>O<sub>3</sub>). The resulting Co-MOF/Ti:Fe<sub>2</sub>O<sub>3</sub> modified photoanode exhibits an enhanced photocurrent density of 1.80 mA∙cm<sup>−2</sup> at 1.23 V, surpassing those of the Ti:Fe<sub>2</sub>O<sub>3</sub> (1.53 mA∙cm<sup>−2</sup>) and bare Fe<sub>2</sub>O<sub>3</sub> (0.59 mA∙cm<sup>−2</sup>) counterparts. Additionally, significant enhancements in charge injection and separation efficiencies, applied bias photon-to-current efficiency (ABPE), incident photon to current conversion efficiency (IPCE), and donor density (N<sub>d</sub>) were observed. Notably, a minimal photocurrent decay of only 5% over 10 h demonstrates the extraordinary stability of the Co-MOF/Ti:Fe<sub>2</sub>O<sub>3</sub> photoanode. This work highlights the efficacy of polynuclear Co-based MOFs as OER cocatalysts in designing efficient and stable photoanodes for PEC water splitting applications.</p>