Highly active and durable electrocatalysts are essential for producing hydrogen fuel through the hydrogen evolution reaction (HER). Here, a uniform deposition of Ru nanoparticles strongly interacting with oxygen-rich carbon nanotube architectures (Ru-OCNT) through ozonation and hydrothermal approaches has been designed. The hierarchical structure of Ru-OCNT is made by self-assembly of oxygen functionalities of OCNT. Ru nanoparticles interact strongly with OCNT at the Ru/OCNT interface to give excellent catalytic activity and stability of the Ru-OCNT, as further confirmed by density functional theory. Owing to the hierarchical structure and adjusted surface chemistry, Ru-OCNT has an overpotential of 34 mV at 10 mA cm À 2 with a Tafel slope of 27.8 mV dec À 1 in 1 M KOH, and an overpotential of 55 mV with Tafel slope of 33 mV dec À 1 in 0.5 M H 2 SO 4 . The smaller Tafel slope of Ru-OCNT than Ru-CNT and commercial Pt/C in both alkaline and acidic electrolytes indicates high catalytic activity and fast charge transfer kinetics. The asproposed chemistry provides the rational design of hierarchically structured CNT/nanoparticle electrocatalysts for HER to produce hydrogen fuel.
Herein, heteroatoms of N and P doped carbon layer over MnO2 nanorods surface was fabricated by an in situ anile polymerization reaction based on aniline and phytic acid (MnO2@PANI) following thermal annealing. A core‐shell structure with manganese oxide as the core and N, P‐doped carbon layer as the shell was revealed by structure and morphology analysis. Temperature dependence of phase structure and ORR activity was found by a series of physical and electrochemical studies for MnO2@PANI sample obtained at different annealing temperatures. The MnO2@PANI obtained at 800 °C exhibited the best catalytic performance, close to Pt/C for ORR; Specifically, the onset potential and half‐wave potential were 0.92 and 0.76 V respectively, outperforming their counterparts of MnO2 and N, P−C alone. The improved catalytic performance can be attributed to the conductivity improvement and the synergistic effect of the intrinsic activity of manganese oxide and N, P‐doped carbon layer. The current work demonstrated an efficient approach to boost the catalytic performance for ORR catalyzed by manganese oxide.
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