The purpose of this project is to develop an ion funnel to selectively transmit negatively charged ions into a reaction channel for the study of catalytic species. The primary reaction studied is the Hydrogen Evolution Reaction (HER), which is essential to electrochemical water splitting for hydrogen fuel production.
The ions are initialized via laser ablation (green arrow) in a gas pulse. As the pulse expands, the positively charged ions (cations, orange) are defocused by the ion funnel while the negatively charged ions (anions, blue) are focused into the reaction channel.
Mastercam Drawings of Ion Funnel Components
Ion Simulations with SIMION
Voltages exert forces on ions similar to the way gravity exerts a force on a ball rolling down a hill. The key rule of thumb here is that likes repel, and opposites attract. We can think of changing the voltages on components in an electric field as changing the shape of the hill the ball rolls down. This figure is a graphical representation of what that hill looks like for the ion funnel. The negatively charged ions (anions, blue) are funneled into the reaction channel, while the positively charged ions (cations, red) experience a different shaped hill that propels them in the opposite direction.
Ion Funnel Photos
Ion funnel in experimental apparatus (left). Close-up of ion funnel concentric rings (right).