(215d) Applications of ?-Nickel Hydroxide Catalyst for Electrochemical Water Splitting

Nickel hydroxide is a highly effective material for several electrochemical applications. Especially the disordered α-Ni(OH)₂ polymorph shows excellent performance for energy related applications. This work will cover few demonstrations of α-Ni(OH)₂ electrodeposits specifically geared towards catalysis of oxygen evolution reaction (OER) in alkaline electrochemical water splitting. Three different Ni(OH)₂-based nanostructured deposits fabricated using electric field directed deposition techniques will be explored. Standalone Ni(OH)₂ based deposits, as well as, stainless steel nanoparticle and carbon nanotube (CNT) supported Ni(OH)₂ deposits will be shown to be highly active OER catalysts. The standalone Ni(OH)₂ nanocarpets show remarkable bubble repellent behavior allowing durable and efficient catalysis. OER overpotentials as low as 450 mV to sustain 500 mA/cm² could be obtained with Ni(OH)₂ modified stainless steel deposits. The Ni(OH)₂ decorated CNT deposits can be further enhanced with platinum to produce excellent hydrogen evolution reaction catalysis. The OER/HER electrode combination shows stable water splitting at 10 mA/cm² for 24 hours. Effective strategies toward exploiting excellent Ni(OH)₂ activity via binder-free electrodeposits will be demonstrated.