A Hierarchical 3D TiO2/Ni Nanostructure as an Efficient Hole‐Extraction and Protection Layer for GaAs Photoanodes

2020

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Photoelectrochemical (PEC) water splitting is a promising clean route to hydrogen fuel. The best‐performing materials (III/V semiconductors) require surface passivation, as they are liable to corrosion, and a surface co‐catalyst to facilitate water splitting. At present, optimal design combining photoelectrodes with oxygen evolution catalysts remains a significant materials challenge. Here, we demonstrate that nickel‐coated amorphous three‐dimensional (3D) TiO2 core‐shell nanorods on a TiO2 thin film function as an efficient hole‐extraction layer and serve as a protection layer for the GaAs photoanode. Transient‐absorption spectroscopy (TAS) demonstrated the role of nickel‐coated (3D) TiO2 core‐shell nanorods in prolonging photogenerated charge lifetimes in GaAs, resulting in a higher catalytic activity. This strategy may open the potential of utilizing this low‐cost (3D) nanostructured catalyst for decorating narrow‐band‐gap semiconductor photoanodes for PEC water splitting devices.

@article{2020chemsuschem,
  title = {A Hierarchical 3D TiO2/Ni Nanostructure as an Efficient Hole‐Extraction and Protection Layer for GaAs Photoanodes},
  author = {Alqahtani, M. and Kafizas, A. and Sathasivam, S. and Ebaid, M. and Cui, F. and Alymani, A. and Jeong, H.-H and Lee, T.-C. and Fischer, P. and Parkin, I. and Gr{\"a}tzel, M. and Wu, J.},
  journal = {ChemSusChem},
  volume = {13},
  number = {22},
  pages = {6028--6036},
  month = sep,
  year = {2020},
  doi = {10.1002/cssc.202002004},
  url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/cssc.202002004},
  month_numeric = {9}
}