Hierarchical Structure MnO2 Coated PDMS-Carbon Nanotube Sponge as Flexible Electrode for Electrocatalytic Water Splitting and High Performance Supercapacitor

摘要

abstract_textpAs a typical transition metal oxide, MnO2 has great potential in catalysis and energy storage, but its poor conductivity greatly limits its performance. PDMS-carbon nanotube sponges have excellent electrical conductivity and flexibility. Herein, according to the principle of complementary, we propose a novel hierarchical PDMS-carbon nanotube sponge@MnO2 electrode with uniform size and morphology. In view of the structural preponderances and multifunctional of the materials, the PDMS-carbon nanotube sponge@MnO2 has been investigated as the binder-free electrode materials for both supercapacitors and electrocatalysis applications. PDMS-carbon nanotube sponge@MnO2 electrode exhibits an admirable HER property with a low onset potential of 112 mV at -30 mA cm(-2), a minimal overpotential (eta=258 mV), a small Tafel slope (71 mV dec(-1)), large anodic currents and stability for 20 h in 0.1 M H2SO4 solution. Moreover, as supercapacitor electrode, the PDMS-carbon nanotube sponge@MnO2 electrode achieves a specific mass capacitance reaching 124.7 mF cm(-2) at 1 A cm(-2) and good flexibility, which are better than those ternary transition metal oxides. The assembled asymmetric device with the PDMS-carbon nanotube sponge@MnO2 and CNTs respectively as positive and negative electrode has a large window voltage of 1.4 V, and thus acquires an expected specific mass capacitance (422 mF cm(-3) at the current density of 1 A cm(-3)) and an outstanding higher energy density of 15.3 W h kg(-1) (at 371 W kg(-1))./p/abstract_text