Synergetic Modulation of Electronic Properties of Cobalt Oxide via “Tb” Single Atom for Uphill Urea and Water Electrolysis
Sara Ajmal, Aamir Rasheed, Wenxiang Sheng, Ghulam Dastgeer, Quynh Anh T. Nguyen, Peihong Wang, Ping Chen, Shoujie Liu, Viet Q. Bui, Manzhou Zhu, Peng Li, Dingsheng Wang
Abstract
Abstract Exploring single‐atom (SA) catalysts in hybrid urea‐assisted water electrolysis offers a viable alternative to both Hydrogen (H 2 ) generation and polluted water treatment. However, the unfavorable electronic stabilization, low SA content, intrinsically slow kinetics, and imbalanced adsorption‐desorption steps are the bottleneck for its scale‐up implementation. Herein, a rare‐earth Terbium single atom (Tb SA ) is topologically stabilized on defect‐rich Co 3 O 4 (Tb SA @d‐Co 3 O 4 ) by Tb─O co‐ordination for urea oxidation reaction (UOR) and H 2 evolution reaction (HER). Benefitting from the strong Tb SA interaction with the d‐Co 3 O 4, the Tb SA @d‐Co 3 O 4 achieves a 10 mA cm −2 current density at 1.27 V and −35 mV for UOR and HER, respectively. Remarkably, when Tb SA @d‐Co 3 O 4 is applied as a bi‐functional catalyst in a two‐electrode system, it merely requires 1.22 V to acquire 10 mA cm −2 with excellent operational stability for 100 h. The hybrid electrolyzer can be successfully empowered by the triboelectric nanogenerator, AA battery, and solar panel with a nominal potential of 1.5 V. The mechanistic investigation predicts “Tb SA ” insertion in d‐Co 3 O 4 lowered the potential determining step, attributed to balanced reaction energetics for adsorption‐desorption of intermediates and favorable charge transfer characteristics for UOR. This work offers a new paradigm to explore the catalytic properties of rare‐earth “ f ‐block” elements to create advanced electrocatalysts via structural modulation.