Ni–Mo modified metal–organic frameworks for high-performance supercapacitance and enzymeless H2O2 detection

• Published in: CrystEngComm Vol. 22; no. 31; pp. 5145 - 5161
• Main Authors: Li, Yue, Kamdem Pascal, Xiao-Juan, Jin
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2020
• Subjects: Acidification; Activated carbon; Capacitance; Chemical sensors; Contact angle; Electrochemical analysis; Electrode materials; Electrodes; Flux density; Hydrogen peroxide; Liquid phases; Maintenance; Metal-organic frameworks; Molybdenum; Nanoparticles; Nickel; Photoelectrons; X ray photoelectron spectroscopy
• ISSN: 1466-8033
• DOI: 10.1039/d0ce00666a

In this work, we synthesized A(B)-NixMoy-MOFs@AAC hybrids with different molar ratios of nickel and molybdenum through a liquid phase method and a hydrothermal method. The irregularly shaped Ni/Mo nanoparticles are closely anchored on the surface of the MOFs and the A(B)-NixMoy-MOFs are supported on the acidified activated carbon (AAC) with a size of ∼6 nm. Interestingly, the MOF particles are hexahedral under mild liquid conditions and present a cubic shape under hydrothermal conditions. The A(B)-NixMoy-MOFs@AAC hybrids were tested using transmission electron microscopy (TEM), contact angle measurements, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analytical techniques. The prepared A(B)-NixMoy-MOFs@AAC hybrids were then used as electrode materials. In particular, the A(B)-Ni1Mo0.5-MOFs@AAC electrode exhibited excellent electrochemical properties, with a high specific capacitance (1178 F g−1 at 0.5 A g−1 for the A-Ni1Mo0.5-MOFs@AAC electrode and 1145.7 F g−1 at 0.5 A g−1 for the B-Ni1Mo0.5-MOFs@AAC electrode), and exceptional stability (83.40% maintenance of specific capacitance for the A-Ni1Mo0.5-MOFs@AAC electrode and 78.31% maintenance for the B-Ni1Mo0.5-MOFs@AAC electrode at 15 A g−1). Meanwhile, the as-obtained A(B)-Ni1Mo0.5-MOFs@AAC//AAC achieved a high energy density of 85.83 W h kg−1 to 54.05 W h kg−1 (A-Ni1Mo0.5-MOFs@AAC//AAC) and from 68.26 to 36.07 W h kg−1 (B-Ni1Mo0.5-MOFs@AAC//AAC) based on the total mass of active material at a current density in the range of 1 to 25 A g−1. In addition, the A(B)-NixMoy-MOFs@AAC hybrids were also employed as nonenzymatic sensors for the electrochemical detection of H2O2, and exhibited high sensitivity (0.277 μA μM−1 for the A-Ni1Mo0.5-MOFs@AAC sensor and 0.188 μA μM−1 for the B-Ni1Mo0.5-MOFs@AAC sensor) and noteworthy low detection limits of 0.185 and 0.303 μM based on 3 signal–noise ratios, respectively. Therefore, we expect that the A(B)-Ni1Mo0.5-MOFs@AAC electrodes as electrode materials would have potential applications in supercapacitors and the nonenzymatic detection of H2O2.