Ni/Fe2O3 Mott-Schottky heterointerface engineering and phosphate doping synergistically refining d-band center for efficient oxygen evolution reaction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 479; p. 147723
• Main Authors: Xuan, Cuijuan, Shen, Tao, Hou, Baoshan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2024
• Subjects: D-band center; Electrocatalysis; Heterointerface engineering; Phosphate doping; Water oxidation; D-band center; Electrocatalysis; Heterointerface engineering; Water oxidation; Phosphate doping
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.147723

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•Phosphate doped Ni/Fe2O3 Schottky heterostructure is synthesized.•Tailored d-band center induces the optimization of the intermediates adsorption.•Heterointerface and phosphate synergistically boost the intrinsic OER activity.•Excellent catalytic performance for OER and water splitting are achieved.
Developing highly effective non-precious metal-based electrocatalysts is pivotal to overcome unfavorable slow kinetics of oxygen evolution reaction (OER) and large-scale application limitations of noble metals. Herein, a dual-modulation strategy of anion incorporation and Mott-Schottky heterointerface engineering was adopted to synthesize phosphate-doped Ni/Fe2O3 heterostructure (Pi-Ni/Fe2O3). Experimental combined theoretical calculations evident that the strong coupling between Ni and Fe2O3 leads to the redistributed electron and charge at the heterointerface and the reduction of bandgap, and adjusts electronic density of state around active centers into the bargain. Moreover, phosphate incorporation can reduce the probability of anti-bond filling, and serve as proton acceptors to form hydrogen bonds for stabilizing *OOH intermediates. Heterostructure formation and phosphate doping induce the upshift of d-band center of Pi-Ni/Fe2O3, giving lower energy barrier toward OER compared with Fe2O3 and Ni. Consequently, the above merits endow Pi-Ni/Fe2O3 with outstanding OER performance to deliver 10 mA cm−2 at an overpotential of 263 mV, as well as superior electrocatalytic performance for overall water splitting. This study not only reveals the synergistic effect of Schottky heterogeneous interface and phosphate doping, but also sheds light on advancing high-efficiency catalysts from the perspective of proton receptor modification and interface engineering.