Researchers at Australia’s have developed less expensive and more efficient catalysts for producing hydrogen from water-splitting. In a paper in Advanced Functional Materials, they reported introducing a low concentration of gold into Co(OH)2 followed by electrodeposition of Ni(OH)2 to yield a Co(OH)2‐Au‐Ni(OH)2 composite active in overall water splitting.
This material exceeds the activity of Pt for the HER at current densities greater than 40 mA cm−2 and is stable for both reactions for prolonged periods of electrolysis. In a two‐electrode configuration, current densities greater than 175 mA cm−2 for overall water splitting could be readily achieved at an applied voltage of 1.90 V in a commercially relevant electrolyte of 6 m NaOH.—Sultana et al.
Activity for hydrogen evolution or oxygen evolution can be achieved by tuning the gold content between 0.1 and 0.2 at%. Further, they noted, this approach may also be applicable to other metal hydroxide/metal nanomaterial composites.
What we have found is that we can use two earth-abundant cheaper alternatives—cobalt and nickel oxide with only a fraction of gold nanoparticles—to create a stable bi-functional catalyst to split water and produce hydrogen without emissions.
From an industry point of view, it makes a lot of sense to use one catalyst material instead of two different catalysts to produce hydrogen from water.—Professor Anthony O’Mullane
Ummul K. Sultana James D. Riches Anthony P. O’Mullane (2018) “Water Splitting: Gold Doping in a Layered Co‐Ni Hydroxide System via Galvanic Replacement for Overall Electrochemical Water Splitting” Advanced Functional Materials doi: 10.1002/adfm.201804361