MOF@Cellulose Derived Co–N–C Nanowire Network as an Advanced Reversible Oxygen Electrocatalyst for Rechargeable Zinc–Air Batteries

Abstract

Zn–air battery is a promising energy storage device because of its remarkably high energy density. However, development of affordable oxygen catalysts with high eletrocatalytic activity and excellent durability is of critical importance for the implementation of rechargeable Zn–air batteries. Here, we report a novel synthesis of three-dimensional (3D) Co–N–C nanowire network (NN) and its remarkable electrocatalytic performance as a bifunctional electrocatalyst in rechargeable Zn–air batteries. The carbon nanowire network was derived from cost-effective cellulose, with Co and N heteroatom doping achieved by annealing the self-assembled MOF@amine-modified cellulose under N2. As reported here, the best sample synthesized at 800 °C, referred to as 3D Co–N–C NN-800, demonstrated an oxygen reduction reaction (ORR) onset potential of 1.05 V and oxygen evolution reaction (OER) overpotential of 0.47 V (10 mA cm–2). As a result, a Zn–air battery assembled with 3D Co–N–C NN-800 demonstrates a small voltage gap of 0.8 V between charge and discharge and excellent durability, as evidenced by a minimal decay after 30 h operation (90 cycles, 15 mA cm–2). This study demonstrates a novel design strategy to enhance the electrcatalytic site and its homogeneity via the covalently bonded doping, which could be employed for the further development of bifunctional carbonaceous electrocatalysts.

Structural Engineering of Low‐Dimensional Metal–Organic Frameworks: Synthesis, Properties, and Applications

“…[106][107][108][109][110] Plenty of templates with rationally designed structures, e.g., poly styrene-poly-4-vinylpyridine (PS-b-P4VP) block copolymer, [104] cellulose, [111] Te nanowires, [112,113] and ZnO nanorods, [74,[114][115][116] can be used for the preparation of 1D MOFs. [106][107][108][109][110] Plenty of templates with rationally designed structures, e.g., poly styrene-poly-4-vinylpyridine (PS-b-P4VP) block copolymer, [104] cellulose, [111] Te nanowires, [112,113] and ZnO nanorods, [74,[114][115][116] can be used for the preparation of 1D MOFs.…”

“…To date, many LD MOF/non-MOF composites have been synthesized, such as cellulose@ZIF-67 nanowires, [111] Ru/Zn-BTC fibers, [222] ZnO@ZIF-8 rods, [223,224] Cu(HBTC)-1/Fe 3 O 4 -AuNPs nanosheets [225] and so on. To date, many LD MOF/non-MOF composites have been synthesized, such as cellulose@ZIF-67 nanowires, [111] Ru/Zn-BTC fibers, [222] ZnO@ZIF-8 rods, [223,224] Cu(HBTC)-1/Fe 3 O 4 -AuNPs nanosheets [225] and so on.…”

“…Template method is an effective technique to synthesize nanomaterials with controllable size and composition . Plenty of templates with rationally designed structures, e.g., polystyrene‐poly‐4‐vinylpyridine (PS‐b‐P4VP) block copolymer, cellulose, Te nanowires, and ZnO nanorods, can be used for the preparation of 1D MOFs. As one of the most widely used hard templates, track‐etched polycarbonate (PCTE) membrane have already been applied in the synthesis of inorganic nanowires .…”

Recent Advances in Materials and Design of Electrochemically Rechargeable Zinc–Air Batteries

“…Alternatively, MOF was self‐assembled on cost‐effective amine‐modified cellulose fibers. After heat treatment, the cellulose fibers formed conductive carbon nanowire networks in a 3D Co‐N‐C composite . Liu et al functionalized a carbon paper to create graphene‐liked carbon lamellae, and then synthesized MOFs (composed of Co, Zn, and N‐containing ligands) on the carbon paper surface.…”

Importance of Electrocatalyst Morphology for the Oxygen Reduction Reaction

“…[69] The polydopamine (PDA) was selected as the sources of N and C. Wang et al reported a CoÀ NÀ C nanowire by pyrolyzing self-assembled MOF@aminemodified cellulose. [70] The obtained CoÀ NÀ C nanowire has a E 1/2 of 0.90 V (vs reversible hydrogen electrode, RHE; all potentials used in this review are calculated values based on the RHE) compared to the FeÀ N-CNFs (0.824 V) and the FeÀ NÀ C nanorod (0.793 V) measured in 0.1 M KOH. One advantage to use this method is that the morphology of the template determines the morphology of MÀ NÀ C materials.…”