Fast and facile synthesis of carbonate-modified NiFe layered double hydroxide nanosheets by dielectric barrier discharge microplasma: mechanism and application in enhanced water oxidation

A fast and facile approach was designed to fabricate carbonate (Ci)-modified NiFe layered double hydroxide (LDH) nanosheets array on carbon cloth (CC) by dielectric barrier discharge (DBD) microplasma. The whole synthetic process can be completed within 1 h at ambient temperature and pressure. The prepared NiFe LDH-Ci/CC emerges a superior catalytic activity for oxygen evolving reaction in alkaline media, which only demands an overpotential of 240 mV at 20 mA cm(-2) with a high stability for at least 90 h, and shows an excellent turnover frequency value of 0.323 mol O-2 s(-1) at 350 mV. Time-resolved measurements of direct emission spectra for nitrogen second positive system N-2(C-B) were measured in the DBD microplasma discharge. And a high vibrational temperature (T-vib, 3100 K) and rotational temperature (T-rot, 340 K) were obtained, indicating a great chemical reactivity. In addition, the intermediate products of hydroxyl radicals ((OH)-O-center dot) were identified and the possible synthesis mechanism was tentatively proposed. [GRAPHICS] .

Automated summary

In this study, NiFe LDH-Ci/CC nanosheets array was successfully fabricated using DBD microplasma, showing superior catalytic activity for oxygen evolving reaction and high stability. High vibrational temperature and rotational temperature were obtained, indicating great chemical reactivity.