Dynamic self-optimization of hierarchical NiAl architecture catalysing oxygen evolution reaction in alkaline water electrolysis

Deep reconstruction of Ni–Al-based pre-catalysts for a highly efficient and durable anion-exchange membrane (AEM) electrolyzer

“…On the other hand, the HNA-CA-O has a similar porous framework made of NiAl alloy but is covered with wrinkled Ni (oxy) hydroxide nanosheets, similar to what our previous work reported. 11 Their performance towards HER and OER would be evaluated in a three-electrode-test system, respectively. Furthermore, to verify the operational capability of these developed electrodes in actual systems, a 5 cm 2 AEM cell would be constructed, with the HNA-CA-H and HNA-CA-O samples serving as the cathode (HNA-CA-H(−)) and anode (HNA-CA-O(+)), respectively.…”

“…2c), which were consistent with the previous report. 11 The HR-TEM analysis of HNA-CA, as shown in Fig. S2 (ESI †), further indicated that the layer on the surface of HNA-CA consisted of Ni/NiO nanostructure, with numerous O-vacancies distributed inside the nanocrystal and mesopores distributed at their boundaries.…”

“…S8 (ESI †), which aligns with our prior study. 11 The resulting electrode is denoted as HNA-CA-O. The SEM image (Fig.…”

“…These lattice defects signicantly improve the OER kinetics of the HNA-CA-O catalyst by tuning the surface chemical and electronic properties of the Ni(oxy)hydroxide sheet, as we have previously reported. 11,[39][40][41][42][43] Moreover, an in-depth exploration of the valence and oxidation states of HNA-CA and HNA-CA-O was conducted through XPS. The XPS survey spectra of these samples reveal the presence of Ni, Al, O, and K, as depicted in Fig.…”

“…8 Particularly, there is a critical need for costeffective and scalable techniques for developing earthabundant, efficient, and long-lasting catalysts. 9,10 The thermal spraying (TS) process is a highly promising technique for depositing coatings, particularly in developing highly active and durable electrodes/electrocatalysts for water electrolyzers, including alkaline electrolyzers, 11,12 PEM electrolyzers, 13,14 and AEM electrolyzers. 15,16 This process offers several advantages, such as high speed, cost-effectiveness, and scalability, and enables the production of binder-free and sizewithout-limitation electrodes.…”