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In this work, we introduce a unique approach for fabricating a three-dimensional (3D) Cu-ZIF-8/MXene, combing the merits of MOFs and MXene to enhance their overall performance. Subsequently, the synthesis of 3D MXene-based Cu and N-doped porous carbon (Cu-NPCM) composites, characterized by high specific surface area, superior conductivity, and abundant active sites, was achieved through the carbonization and acid etching of Cu-ZIF-8/MXene. Utilizing the resulting 3D Cu-NPCM composites as effective electrocatalyst supports, Ni and Pd NPs were uniformly dispersed, preventing the aggregation of metal NPs. The unique structure of Cu-NPCM, coupled with the synergy of Ni and Pd, facilitates the creation of interconnected channels for rapid reactant and product diffusion, along with a substantial amount of OHad, thereby enhancing the electrocatalytic efficiency. Remarkably, the designed trimetallic Pd/Ni/Cu-NPCM catalyst demonstrates an advanced mass activity of 3641.2 mA mgPd–1 in the methanol oxidation reaction (MOR), surpassing Pd/Cu-NPCM (2200.5 mA mgPd–1), Pd/Cu-NPC (1447.1 mA mgPd–1), and Pd/C (209.3 mA mgPd–1) electrocatalysts by 1.66, 2.51, and 17.4 times, respectively. This research introduces an innovative approach to creating advanced support materials for electrocatalysts, simultaneously expanding the range of potential applications for direct methanol fuel cells (DMFCs). [ABSTRACT FROM AUTHOR]

Summary: Exploring progressed activity and stability, electrocatalyst toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), has been the most considerable factor in extensive commercialization of metal‐air batteries and fuel cells. Herein, Co/N co‐doped 3D hierarchical porous bifunctional oxygen electrocatalyst was synthesized using F127 as soft template and PMMA nanosphere as hard template to build hierarchically ordered macro/mesoporous porous nanostructure. The as‐obtained macro/mesoporous Co‐N‐doped carbon endowing its 3D ordered hierarchical porosity and satisfactory surface area, leading to superior performance for ORR, OER, and rechargeable Zn‐air battery. For ORR, the catalyst showed superior ORR activity with an attractive half‐wave potential of 0.85 V (vs RHE), remarkable methanol tolerance, and robust long‐term stability under alkaline electrolyte. For OER, the as‐synthetized electrocatalyst exhibited low overpotential of 1.67 V (vs RHE) under the current density of 10 mA/cm2. Moreover, the Zn‐air battery assembled from the hierarchical porous catalyst displayed a high peak power density of 146 mW/cm2. [ABSTRACT FROM AUTHOR]

Developing high efficiency and durability catalysts for the electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is fundamental to achieve the large‐scale commercial application of fuel cells and metal‐air batteries. Herein, a series of Co−N doped bi‐functional hierarchical porous electrocatalysts were synthesized using polyvinyl pyrrolidone (PVP) as soft template to assist the Zn/Co bimetal Zeolitic Imidazolate Framework (BMZIF) to form micro‐/mesoporous carbon nanospheres via a convenient one‐step solution synthesis method, followed by pyrolysis to form carbon nanospheres catalysts. The as‐prepared Co/N co‐doped carbon exhibits outstanding performances in the ORR and OER due to the formed hierarchical pores architecture and the high surface area. The catalyst displays superior ORR performance with a high half‐wave potential of 0.89 V, and a remarkable long‐term stability in 0.1 M KOH. In addition, the electrocatalyst elicits a low voltage of 1.72 V under the current density of 10 mA cm−2. Moreover, the zinc‐air battery fabricated with P‐CNCo‐3 delivers a power density of 175.1 mW cm−2, a high specific capacity of 791 mAh g−1 and an energy density of 976 Wh kg−1 at 20 mA cm−2. [ABSTRACT FROM AUTHOR]

Electrode architecture design is of critical importance to the development of advanced hybrid electrode materials for supercapacitors. Here, we report a novel electrode architecture that is composed of Fe2O3 nanocubes and carbon nanotube functionalized carbon. This functionalized electrode demonstrates superior electrochemical performance, characterized by a high capacitance of 1687 mF cm−2 at a current density of 2 mA cm−2, excellent cycling stability, and 95.8% retention after 20 000 cycles. This work presents a new approach for fabricating advanced hybrid electrode materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Robust and efficient catalysts for the oxygen reduction reaction (ORR) are required for the development of various energy storage and conversion devices. In this study, a durable and high-performance Fe3C@graphene ORR catalyst has been developed by the carbonization of urea- and agar-modified Fe2O3 nanorods. The influence of the carbonization temperature and annealing time on the activity and stability of the resulting Fe/ C catalyst was studied in detail. The Fe/C catalyst synthesized at a temperature of 700°C (holding time: 60 min) showed better ORR activity and improved stability compared to a commercial Pt/C catalyst. The improved ORR catalytic activity of the catalyst is due to its high Fe3C content and its good durability results from the unique microstructure of the Fe3C@graphene hybrid. [ABSTRACT FROM AUTHOR]