Professor Jian Wang’s Group Advances Green Hydrogen Research in Nature Communications
Prof. Jian Wang, Assistant Professor of the School of Energy and Environment (SEE) at City University of Hong Kong (CityUHK), has achieved a pioneering advance in hydrogen technology. His latest publication, “Sustainable water oxidation enabled by a complex-doped cobalt oxide electrode”, has been published in Nature Communications. The work introduces a novel complex-doping strategy that dramatically enhances both the activity and long-term stability of cobalt-based oxygen evolution electrodes under practical electrolyzer conditions.
Sustainable, high-performance oxygen evolution reaction (OER) electrodes are a major bottleneck in green hydrogen production. While cobalt-based oxides offer low cost and high activity, they often suffer from uncontrolled in situ reconstruction under practical conditions, leading to poor stability. Regulating reconstruction at high temperature and high current density remains a key challenge for industrially relevant water oxidation catalysis.
In this study, Prof. Wang’s group approached catalyst design from the perspective that reconstruction is inevitable but can be precisely controlled. They report a Ni–Fe–Pd complex co-doping strategy based on lithium cobalt oxide, a material that can be recycled from spent lithium-ion batteries, thereby combining resource sustainability with high electrocatalytic performance. Through systematic screening of doped compositions, the team identified a strong synergistic effect among Ni, Fe, and Pd that precisely regulates in situ reconstruction during OER. Excessive lithium deintercalation and deep cobalt oxidation are suppressed, resulting in the formation of a thin, stable, and highly active spinel surface layer.
Moreover, the electrode’s mass transport properties, including bubble removal capability, were optimized — a critical factor for practical applications. As a result, the optimized electrode operates stably for over 2,000 hours at elevated temperature and delivers 2.5 A cm-2 at 1.58 V in an anion-exchange membrane water electrolyzer, outperforming benchmark RuO₂ electrodes.
More broadly, the study demonstrates that catalyst reconstruction need not be avoided but can be deliberately engineered to enhance both activity and durability. This design philosophy provides a scalable route for developing low-cost, sustainable OER electrodes and advances the practical deployment of cobalt-based catalysts in green hydrogen technologies.
This achievement reinforces CityUHK’s leadership in electrocatalysis and sustainable energy research, contributing impactful solutions toward scalable, durable, and resource-efficient hydrogen production.
The full paper is available at: https://www.nature.com/articles/s41467-025-68064-x