Search

Bifunctional catalyst was prepared by one-step pyrolysis of trimetallic ZIF. The obtained catalyst showed excellent charge–discharge stability in rechargeable Zn-air battery. • A facile and effect strategy is proposed for the synthesis of catalyst precursor. • This strategy reduces the adverse effects of the pyrolysis process on the catalyst. • The coexistence of Co NPs and CoFe-N x improves the ORR/OER activity. • The catalyst displays excellent durability as a cathode for Zn-air battery. Searching for high active, low cost and durable catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remains challenge in developing metal-air battery cathodes. Herein, we proposed a novel bifunctional catalyst derived from the pyrolysis of Co/Fe/Zn trimetallic zeolitic imidazolite framework. The obtained Co@CoFe 0.01 N C catalyst displays desirable activity for both ORR and OER (E 1/2 = 0.844 V, E j=10 = 1.654 V). The Zn-air battery equipped with Co@CoFe 0.01 N C catalyst on the cathode exhibits a high peak power density of 174.1 mW cm−2, which is much superior than that of commercial 20% Pt/C (87.6 mW cm−2). Significantly, the designed Co@CoFe 0.01 N C presents an outstanding stability for over 100 h in rechargeable Zn-air battery. [ABSTRACT FROM AUTHOR]

Electrolytic water splitting, consists of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), still has many challenges because of the high cost and scarity of the indispensable noble metal catalysts. Herein, the costless and effective NiFe layered double hydroxide (NiFe-LDH), supported on the Ti 3 C 2 T x modified 3D nickel foam (NF), is used instead of noble metal to intensify the transfer ability of the charges as well as ions in the OER catalysis process. The prepared NiFe-LDH/Ti 3 C 2 T x /NF electrode has a lower overpotential (240 ​mV ​at 50 ​mA ​cm−2) and Tafel slope (82 ​mV dec−1) as compared with that of IrO 2 /Ti 3 C 2 T x /NF(400 ​mV, 252 ​mV dec−1). Meanwhile, it has a good endurance and stability with a negligible voltage changing after 15 ​h of testing. The work provides reference for the synthetic of catalyst with high catalytic kinetics and activity in the field of electrolytic water splitting. The Graphical Abstract mainly includes the schematic illustration of the fabrication of effectively NiFe-LDH/Ti 3 C 2 T x /NF electrocatalytic electrode by two-step electrodeposition, and LSV curves of different electrodes. Image 1 • Ti 3 C 2 T x is used to functionally modify NF interface to support NiFe-LDH catalyst. • NiFe-LDH catalyst can be deposited more uniformly on the Ti 3 C 2 T x modified NF interface. • The contact angle of NiFe-LDH/Ti 3 C 2 T x /NF interface is approximately 0°, showing good hydrophilic performance. [ABSTRACT FROM AUTHOR]