Nanoscale Discharge Electrode for Minimizing Ozone Emission from Indoor Corona Devices

Abstract

Ground-level ozone emitted from indoor corona devices poses serious health risks to the human respiratory system and the lung function. Federal regulations call for effective techniques to minimize the indoor ozone production. In this work, stable atmospheric corona discharges from nanomaterials are demonstrated using horizontally suspended carbon nanotubes (CNTs) as the discharge electrode. Compared with the conventional discharges employing micro- or macroscale electrodes, the corona discharge from CNTs could initiate and operate at a much lower voltage due to the small electrode diameter, and is thus energy-efficient. Most importantly, the reported discharge is environmentally friendly since no ozone (below the detection limit of 0.5 ppb) was detected for area current densities up to 0.744 A/m(2) due to the significantly reduced number of electrons and plasma volume generated by CNT discharges. The resulting discharge current density depends on the CNT loading. Contrary to the conventional wisdom, negative CNT discharges should be used to enhance the current density owing to the efficient field emission of electrons from the CNT surface.

Enhanced ionic wind generation by graphene for LED heat dissipation

“…When the positive voltage was applied to the graphene‐decorated IWCS, the corona current did not increase, and the corona discharge occurred with difficulty. This was because the graphene surface had hydroxyl, carboxyl, and other functional groups, which was negative charged, making it easy to absorb positive ions . The positive corona discharge current was about two orders of magnitude lower than the negative corona discharge current.…”

“…They are good candidates for developing stable atmospheric corona discharge. Boet al used horizontally suspended CNTs as the discharge electrode, which demonstrated that the corona discharge could operate at a much lower voltage. In their subsequent research, vertically oriented graphene was grown on metallic wires for greener corona discharges.…”

Ordered hybrid nanoneedle arrays for gas sensing

“…18 Three successive air ionization I-V curves measured from Pt/Si hybrid nanoneedle array gas sensing device, where the repeatability is confirmed by variation of less than 0.…”

“…One-dimensional nanomaterials (ODNM), in particular, such as carbon nanotube, zinc oxide nanowire or silicon nanowhisker, allow the extensively application as the ideal field ionization devices [11][12][13][14]. In this case, when the applied voltage is raised up to a certain value, the ambient gas will generate conductive plasma to bridge the tips of ODNM and counter-electrode [11,[15][16][17][18][19]. Therefore, a steep increment of ion current can be detected immediately in the measurement circuit.…”

Engineered metal based nanomaterials in aqueous environments

“…Nanoscience and nanotechnology offer new opportunities for making superior materials for use in a wide range of applications important in industry, energy and health. [1][2][3][4][5][6][7] Because of their use, we can expect that these manufactured materials have the potential to get into the environment sometime during production, distribution, use or disposal. 8 Thus, there are many questions as to the EHS of nanomaterials.…”