Anew type of hierarchically mesoporous cobalt ferrite oxide nanosheets, 10 CoFe 2 O 4 nanosheets, hasbeen successfully fabricated viaa simple hydrothermal method on the Ni 11 foamfollowed by a post-annealing treatment. This CoFe 2 O 4 nanosheets was employedas a 12 supercapacitor electrodeand exhibitedan excellent capacitance of 503 F g -1 at a current density of 13 2A g -1 . When the current density increased to 20 A g -1 , the capacitance of CoFe 2 O 4 nanosheets can 14 maintain78.5% (395 F g -1 )of the initial value,indicating the remarkable rate capability of the 15 as-prepared CoFe 2 O 4 nanosheets. An aqueous asymmetric supercapacitor (ASC) based on 16 CoFe 2 O 4 nanosheets as a positive electrode and the activated carbon (AC) as a negative electrode 17 was assembled for the first time. The as-fabricated ASC delivered a specific capacitance of 73.12 18 F g -1 at a current density of 1.2 A g -1 in a voltage window of 1.5 V. The CoFe 2 O 4 //AC ASC could 19 achieve a high energy density of 22.85 W h kg -1 and good long-term cycling stability (98% 20 retention after 5000 cycles).These results demonstrated that CoFe 2 O 4 nanosheets could be one of 21 the promising electrode material for supercapacitors applications. 22 23 Keywords:CoFe 2 O 4 nanosheets, mesopores, asymmetric supercapacitors, electrochemicalenergy 24 storage. 25 26 27

No abstract

No abstract

No abstract

Triethylamine (TEA) is a widely used volatile organic chemical, which is harmful and can cause headache, dizziness, and respiratory discomfort. Developing an efficient sensor to detect trace amounts of TEA is significant for industrial and healthcare monitoring. In this work, SnO 2 with a threedimensional ordered macroporous structure (3DOM) was prepared through a polymethylmethacrylate sphere template route. The TEA sensing performance of the 3DOM SnO 2 was enhanced through Pt loading. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images and X-ray absorption fine-structure analysis indicate that Pt on the 3DOM 0.20% Pt/SnO 2 surface mainly exists in the state of atomic dispersion, which results in more active sites, higher Hall mobility and active oxygen contents, and lower response energy barriers. The 0.20% Pt/SnO 2 sensor has a low operating temperature of 80 °C and a low limit of detection (0.32 ppb). Because of the uniform adsorption of TEA on the atomically dispersed Pt, the 3DOM Pt/SnO 2 sensor exhibits high selectivity.