Frontiers in Chemistry (Aug 2024)

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

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

DOI
https://doi.org/10.3389/fchem.2024.1454524
Journal volume & issue
Vol. 12

Abstract

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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:Fe2O3). The resulting Co-MOF/Ti:Fe2O3 modified photoanode exhibits an enhanced photocurrent density of 1.80 mA∙cm−2 at 1.23 V, surpassing those of the Ti:Fe2O3 (1.53 mA∙cm−2) and bare Fe2O3 (0.59 mA∙cm−2) 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 (Nd) were observed. Notably, a minimal photocurrent decay of only 5% over 10 h demonstrates the extraordinary stability of the Co-MOF/Ti:Fe2O3 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.

Keywords