2D Metal–Organic Framework Derived CuCo Alloy Nanoparticles Encapsulated by Nitrogen‐Doped Carbonaceous Nanoleaves for Efficient Bifunctional Oxygen Electrocatalyst and Zinc–Air Batteries

Abstract

The development of efficient bifunctional electrocatalysts for the oxygen reduction reaction( ORR) and oxygen evolution reaction( OER) still remains ac hallenge in aw ide range of renewable energy technologies. Herein, CuCo alloy nanoparticlese ncapsulatedb yn itrogen-doped carbonaceous nanoleaves (CuCo-NC) have been synthesized from aC u(OH) 2 /2D leaf-like zeolitic imidazolate framework (ZIF-L)-pyrolysis approach. Leaf-like Cu(OH) 2 is first prepared by the ultrasound-induced self-assembly of Cu(OH) 2 nanowires. The efficient encapsulation of Cu(OH) 2 in ZIF-L is ob-tained owing to the morphologyf itting between the leaflike Cu(OH) 2 and ZIF-L. CuCo-NC catalysts present superior electrocatalytic activity and stability toward ORR and OER over the commercial Pt/C and IrO 2 ,r espectively,w hich are furtheru sed as bifunctionalo xygen electrocatalysts in Zn-air batteries and exhibit impressive performance,w ith ah igh peak powerdensity of 303.7 mW cm À2 ,large specific capacity of up to 751.4 mAh g À1 at 20 mA cm À2 ,a nd as uperior recharge stability.

Fe/Fe3C-NC Nanosheet/Carbon Nanotube Composite Electrocatalysts for Oxygen Reduction Reaction

“…Raman spectra were conducted to assess the information of disorder and graphitization of carbon. The G band is assigned to the sp 2 graphitic carbons, while the D band indicates the defective sites of disordered sp 3 carbons in the composite, which will promote the electron transfer ability and provide more catalytic centers, respectively. − Raman spectra of G-Fe/Fe 3 C-NC/CNTs show two distinguished peaks at D band (1357 cm –1 ) and G band (1578 cm –1 ) (Figure b). The calculated I D / I G for G-Fe/Fe 3 C-NC/CNTs is 1.0, which is slightly larger than Fe/Fe 3 C-NC/CNTs (0.99) (Figure S4) and NC (0.98), indicating that more defective sites are formed in G-Fe/Fe 3 C-NC/CNTs.…”

Advances in Zeolite Imidazolate Frameworks (ZIFs) Derived Bifunctional Oxygen Electrocatalysts and Their Application in Zinc–Air Batteries

“…To this end, Huo et al reported CuCo-NC catalysts, obtained by the carbonization of a 2D leaf-like Cu(OH) 2 /ZIF-L material (Figure 11b). [88] Morphological studies reveal that Cu(OH) 2 @ZIF-L-Co nanosheets adopt a leaf-like structure (Figure 11c). After pyrolysis, the catalysts retain their morphology with a reduction in thickness to 180 nm.…”

“…Reproduced with permission. [88] Copyright 2019, Wiley VCH. e) Schematic illustration of the preparation of 1D cobalt phosphide embedded into a nitrogen, sulfur, phosphorus codoped carbon matrix (referred to as CoP@mNSP-C) with an integrated in situ zeolitic imidazolume framework-67 (ZIF-67) conversion and crosslinking of poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) approaches.…”

Air Electrodes for Flexible and Rechargeable Zn−Air Batteries

“…Theoretical calculations indicated that the bimetal NPs embedded in NC materials facilitated charge redistribution at the interfaces, causing electron transfer from metals to NC, thus favoring the enhancement in the ORR and OER activities. [ 84,85 ] Several kinds of bimetal or trimetal NPs coated by NC materials have been investigated for the OER/ORR catalysts, such as CoFe@NCNTs, [ 85–88 ] CoFe−Co@PNC, [ 89,90 ] CoNi@NCNT, [ 91 ] NiFe/N‐CNT, [ 92,93 ] NiFe@N‐CFs, [ 94,95 ] Ni 3 Fe/NPG, [ 96–98 ] Mn/Fe‐HIB‐MOF, [ 99 ] CoCu−NC, [ 100 ] FeNiCo@NC‐P, [ 101 ] and Mn/Co−N−C. [ 102 ] FeCo NCs with different Fe/Co ratios coupled with NCNTs were investigated in terms of Fe/Co mass ratios and their effects on catalytic activity.…”