Out of several different promising first-row transition metals (Ni, Co, Mn and Fe) to be used for the Oxygen Evolution Reaction (OER) in a water splitting system, Nickel Oxide (NiO) turns out to be the most promising of them all, with the highest catalytic activity [1-2]. One of the key limitations on water electrolysis is that it is thermodynamically unfavorable due to demanding a significant amount of energy to make the reaction happen at an appreciable rate [2]. This further pushes the need for an efficient catalyst material to be used for anode in a photoelectrochemical (PEC) cell.

In this work, a thin film of nickel oxide (NiO) is deposited with RF magnetron sputtering technique on quartz, glass and indium tin oxide (ITO) substrates in pure argon atmosphere respectively. The thin films are characterized by Ultraviolet-visible spectroscopy (Uv-Vis), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), X-Ray Diffraction (XRD) analysis and 4-probe resistivity measurements. Typical UV-Vis and X-ray diffraction patterns (Fig. 1a-b) show that thin film NiO are successfully fabricated on these substrates. It can be seen from Figure 1b that increase in temperature significantly increases the material crystallinity, with some peaks becoming clearly more visible. From Table 1 we can deduct that the increase in power increase oxygen in the compound. The electrical properties are to be measured at probe stations for low temperatures (5K) up to room temperature. In summary, the phase transition of thin film NiO as well as light absorption from 220 to 850 nm have been investigated on these substrates.

References

[1] P. C. K. Vesborg, B. Seger, I. Chorkendorff, Recent development in Hydrogen Evolution Reaction Catalysts and their Practical Implementation, The Journal of Physical Chemistry Letters (2015). DOI: 10.1021/acs.jpclett.5b00306

[2] Y. Cheng, S. P. Jiang, Advances in electrocatalysts for oxygen evolution reaction of water electrolysis-from metal oxides to carbon nanotubes, Progress in Natural Science: Materials International (2015), DOI: 10.1016/j.pnsc.2015.11.008