Supercapacitor performances are influenced by binder types and contents in the electrodes. The electrochemical performances of activated carbon (AC) with Nafion, poly(tetrafluoroethylene) (PTFE) and poly(vinylidenedifluoride) (PVDF) and different contents of each binder were investigated by cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS). The optimal content of binder in the electrode is 10 wt% for Nafion and PTFE, but only 5 wt% for PVDF. The specific capacitances of the AC electrodes with optimal content of Nafion, PTFE and PVDF are respectively 131.3, 156.6 and 160.6 F g -1 ; their corresponding specific capacitances retain 87%, 91% and 79.6% after 2000 CV cycles with a scan rate of 200 mV s -1 . Therefore, PTFE is the best suitable binder for supercapacitors and its optimal content is 10 wt%.

The development of efficient bioorthogonal reactions for sensing of endogenous biomolecules and for bioconjugation should be of paramount importance in the field of chemical biology. In this work, the o,o'-difluorinated aromatic azide was firstly employed to develop a new fast-response fluorescent probe 1 for HS detection and for bioorthogonal reactions. Compared with non- and mono-fluorinated probes, 1 showed faster reaction toward HS, the third gasotransmitter, in buffer (pH 7.4), implying that the reaction rate could be enhanced by the dual-fluorine groups. Furthermore, such enhanced reaction rates of 1 were also observed in the Staudinger reaction and strain-promoted azide-alkyne cycloaddition (SPAAC) based on the comparison studies of the non-fluorinated probe. Our results firstly highlight that the o,o'-difluorinated aromatic azide group should be useful for fast bioorthogonal reactions and HS detection.

An o-fluorinated-azido-capped rhodamine probe can react with H2S efficiently and selectively to give large off-on fluorescence enhancement. The probe was used to develop an assay for cystathionine β-synthase acitivity and for in situ visualization of endogenously produced H2S in living cells.

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The redox flow battery (RFB) is considered one of the most attractive energy storage technologies because of its high efficiency, long service life and great safety.