光谱法研究盐溶液浓度对辉光放电活化液体的影响

Effect of NaCl concentration on an atmospheric glow discharge activated liquid activation by spectroscopic methods

大气压辉光放电具有低气压辉光放电的均匀性和较高的化学活性,且摆脱了真空装置的限制.液面上的大气压辉光放电除了具有以上优点外,还具有活性粒子浓度高等优势,因此在材料改性、生物医疗等领域具有非常广泛的应用前景.本文采用针-液体电极直流放电装置,在液体电极上方产生了大气压辉光放电,并用于活化不同浓度的NaCl溶液.发射光谱表明,不同浓度液体电极放电均包含N2的第二正带系、N2^+的第一负带系、OH自由基和O I.基于发射光谱,测量了液面附近的氧原子谱线强度、谱线强度比I391.4/I337.1和振动温度.利用吸收光谱测量了O3浓度.发现它们均随着放电电流的增大而增大,且在一定电流下,随盐溶液浓度减小而增大.经过相同活化时间,溶液的H2O2浓度随着放电电流的增大而增大.在一定放电电流下,H2O2浓度随盐溶液浓度增大而减小。

Atmospheric pressure glow discharge has similar advantages owing to glow discharge obtained at low pressure,high chemical reactivity and being dispensable of expensive vacuum device.In particular,increasing attention is paid to atmospheric pressure glow discharge above liquid surface due to abundance with reactive species,which has extensive application potentials in many fields,including sterilization,plant growth,environmental protection,etc.In this paper,a needle-liquid electrode device with different concentrations of NaCl is used to generate atmospheric pressure glow discharge above solution.Optical emission spectra show that the liquid-electrode discharges with different NaCl concentrations present similar spectral lines,which mainly include the second system of nitrogen molecules(337.1nm),the first negative system of nitrogen molecular ions(391.4nm)and O I.However,intensity ratio of spectral lines is different.Furthermore the O I intensity,the intensity ratio(I391.4/I337.1)and vibrational temperature of discharge are measured by optical emission spectroscopy.Results show that the intensity ratio and vibrational temperature increase with increasing discharge current.For a given current,the intensity ratio and the vibrational temperature decrease with increasing NaCl concentration of liquid electrode.In addition,ozone concentration in gas phase is measured by UV absorption method,which increases with increase of discharge current.For a given current,it decreases with increasing NaCl concentration.In addition,H2O2concentration in solution increases with increasing discharge current.For a given current,it decreases with increasing NaCl concentration.