A polythreaded MnII-MOF and its super-performances for dye adsorption and supercapacitors

Abstract

A new polythreaded Mn^II-MOF based on a tridentate N-containing ligand was synthesized via a hydrothermal method, namely, [Mn₂(Tipa)₂(1,4-bdc)₂(H₂O)₂]·3H₂O (MnTB), where Tipa and 1,4-bdc are short for tri(4-imidazolylphenyl)amine and 1,4-benzenedicarboxylate. MnTB possesses a fascinating 2D → 2D polyrotaxane layer with a (4²·6)(4²·6³·8) topology, and these layers are extended into a 3D polythreaded framework with a polythreaded character. The crystal was pulverized and directly used as both a dye adsorbent and supercapacitor. In the adsorption test, MnTB showed great adsorption ability for methyl orange (MO), where the maximum adsorption capacity was about 1500 mg g⁻¹. When tested as a supercapacitor, MnTB exhibited a high capacitance of 1357.8 F g⁻¹ at 1 A g⁻¹ in 6 M KOH solution and achieved no attenuation after 2000 cycles. The asymmetric supercapacitor device (MnTB//AC) achieved 114.6 F g⁻¹ at 1 A g⁻¹ and a maximum energy density of 35.8 W h⁻¹ kg⁻¹ at a power density of 750 W kg⁻¹ with a voltage window of 1.5 V.