Transparent Catalytic Nickel Oxide Protecting Films for Photoanodes

Sun, K. et al. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films. PNAS 112(12), 3612-3617, DOI: 10.1073/pnas.1423034112 (2015).


Scientific Achievement

Reactively sputtered NiOx layer provides a transparent, anti-reflective, conductive, chemically stable, inherently catalytic coating that stabilizes many efficient and technologically important semiconducting photoanodes.

Significance & impact

Demonstrated protection scheme allows the use of many high-efficiency, small-band-gap photoanodes in an integrated water-splitting device.

 

 

Top:  SEM image of a cross-section of a sputtered NiOx film;  Bottom:  Optical images of NiOx films with various thicknesses and of 15-nm metallic Ni on quartz substrates

  Reprinted with permission from Sun, K. et al. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films. PNAS 112(12), 3612-3617, DOI: 10.1073/pnas.1423034112 (2015).

 

Reprinted with permission from Sun, K. et al. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films. PNAS 112(12), 3612-3617, DOI: 10.1073/pnas.1423034112 (2015).

Research Details

  • NiOx films exhibit overpotentials within 70 mV of the lowest value reported to date for water oxidation in 1.0 M KOH at 10 mA/cm2.
  • The optical properties of NiOx films are consistent with those typically exhibited by transparent conducting oxides.
  • NiO-coated electrodes showed more than 1000-h stable operation in 1 M KOH under 1 Sun illumination.

Contact:  nslewis@caltech.edu