Interfacial charge manipulation enhancing H-bond connectivity for promoted oxygen evolution

Interfacial hydrogen bond connectivity (HBC) of electrical double layer (EDL) has been identified as a critical factor for many electrocatalytic reactions, However, there is a lack of systematic investigation on the correlation between HBC and oxygen evolution reaction (OER) kinetics, and the advanced strategies to rationally manipulate HBC. Herein, we proposed an interfacial charge manipulation (ICM) methodology to engineer HBC and enhance OER kinetic of various electrocatalysts including Ni3FeN and the benchmark oxides (RuO 2 , Ni(OH) 2 , Co(OH) 2 , FeNi LDH, and FeCo LDH). With Ni 3 FeN as a model catalyst, we systematically studied the influence of different anion chemisorption (NO 3 – , SO 4 2– , and PO 4 3– ) on HBC and establishing a positive correlation between OER activity and the charge of anions. Electrochemical tests show that the modified Ni 3 FeN catalysts with NO 3 – , SO 4 2– , and PO 4 3– exhibit 1.1-, 1.4-, and 2.3-fold activity enhancements at 1.5–1.6 V vs. RHE relative to the raw Ni 3 FeN, respectively. The in-situ spectroscopy and AIMD reveal that high anion charges increase four-hydrogen-bonded water populations, strengthening HBC to promote proton transfer across the EDL during deprotonations step and lower energy obstacle of the rate-determining step. This work has offered a new paradigm to regulate the interfacial HBC at molecular scale for promoting OER.