Synergistic Enhancement of Water-Splitting Performance Using MOF-Derived Ceria-Modified g-C₃N₄ Nanocomposites:...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Improving the photoelectrochemical (PEC) performance of graphitic carbon nitride (g-C₃N₄) is crucial for efficient water oxidation.
• Charge recombination is a key limiting factor in the PEC performance of g-C₃N₄.

Purpose of the Study:

• To enhance the PEC performance of g-C₃N₄ nanosheets (NSs) by creating nanocomposites (NCs) with metal-organic framework (MOF)-derived porous CeO₂ nanobars (NBs), ZnO nanorods (NRs), and TiO₂ nanoparticles (NPs).
• To investigate the structure-property relationships and stability of these novel NCs for application as efficient photoanodes.

Main Methods:

• Synthesis of CeO₂ NBs and g-C₃N₄ NSs via calcination, and ZnO NRs and TiO₂ NPs via sol-gel method.
• Fabrication of NC-based photoanodes using a binder-free brush-coating method.
• Evaluation of PEC performance using electrochemical techniques and stability prediction via Long Short-Term Memory (LSTM) neural networks.

Main Results:

• Binary g-C₃N₄/CeO₂ (gC20) NCs showed a 2.3-fold increase in current density compared to bare g-C₃N₄ NSs.
• Ternary gC20/TiO₂ (gCT50) and gC20/ZnO (gCZ50) NCs achieved significantly higher current densities (1.810 and 1.440 mA/cm², respectively).
• Enhanced performance is attributed to increased donor densities, reduced charge transfer resistance, efficient charge transport, and higher surface areas with beneficial defects.

Conclusions:

• The developed organic-inorganic hybrid NCs demonstrate superior PEC performance for water oxidation.
• These materials hold great promise for advancing efficient photoanode design in water-splitting technologies.
• The study highlights the potential of combining different nanomaterials to overcome limitations in photocatalysis.