A gliding electric arc(glidarc)discharge generates a low-temperature plasma at atmospheric pressure.When the discharge occurs in humid air as the feed gas,the chemistry of a glidarc plasma consists of in situ formatio...A gliding electric arc(glidarc)discharge generates a low-temperature plasma at atmospheric pressure.When the discharge occurs in humid air as the feed gas,the chemistry of a glidarc plasma consists of in situ formation of HO°and NO°as the primary chemical species.Tungsten trioxide(WO_(3))nanoparticles were successfully prepared by exposure of a liquid precursor to glidarc plasma.The WO_(3)samples were calcined at three different temperatures(300℃,500℃and 800℃),resulting in different pure polymorphs:γ-WO_(3)(at 300℃),β-WO_(3)(at 500℃)andα-WO_(3)(at 800℃)according to x-ray diffraction analysis.The identification of WO_(3)compounds was also confirmed by attenuated total reflection Fourier transform infrared spectroscopy analysis.Increase in the calcination temperature of WO_(3)induced a decrease in its specific surface area according to Brunauer–Emmett–Teller nitrogen physisorption analysis.The UV-visible results showed that the absorption bands of plasma-WO_(3)samples were more intense than those of WO_(3)samples obtained by a precipitation route,a classical method used for comparison.Consequently,this parameter can improve the photocatalytic properties of WO_(3)under visible light.The photodegradation(in sunlight conditions)of gentian violet,chosen as a model pollutant,confirmed the photocatalytic properties of plasma-WO_(3)samples.This novel synthesis method has great potential to improve the efficiency of advanced tungsten trioxide-based functional material preparation,as well as in pollution-reducing and energy-saving tungsten extractive metallurgy.展开更多
文摘A gliding electric arc(glidarc)discharge generates a low-temperature plasma at atmospheric pressure.When the discharge occurs in humid air as the feed gas,the chemistry of a glidarc plasma consists of in situ formation of HO°and NO°as the primary chemical species.Tungsten trioxide(WO_(3))nanoparticles were successfully prepared by exposure of a liquid precursor to glidarc plasma.The WO_(3)samples were calcined at three different temperatures(300℃,500℃and 800℃),resulting in different pure polymorphs:γ-WO_(3)(at 300℃),β-WO_(3)(at 500℃)andα-WO_(3)(at 800℃)according to x-ray diffraction analysis.The identification of WO_(3)compounds was also confirmed by attenuated total reflection Fourier transform infrared spectroscopy analysis.Increase in the calcination temperature of WO_(3)induced a decrease in its specific surface area according to Brunauer–Emmett–Teller nitrogen physisorption analysis.The UV-visible results showed that the absorption bands of plasma-WO_(3)samples were more intense than those of WO_(3)samples obtained by a precipitation route,a classical method used for comparison.Consequently,this parameter can improve the photocatalytic properties of WO_(3)under visible light.The photodegradation(in sunlight conditions)of gentian violet,chosen as a model pollutant,confirmed the photocatalytic properties of plasma-WO_(3)samples.This novel synthesis method has great potential to improve the efficiency of advanced tungsten trioxide-based functional material preparation,as well as in pollution-reducing and energy-saving tungsten extractive metallurgy.
