03/27/2023
By Danielle Fretwell

The Francis College of Engineering, Department of Chemical Engineering, invites you to attend a doctoral dissertation proposal defense by Zhengyang Yang on “Synthesis and Characterization of Cu-based Nanoneedle Array by Template-assisted Electrodeposition and Their Applications in Electrochemical Catalysis and Sensing.”

Candidate Name: Zhengyang Yang
Degree: Doctoral
Defense Date: Monday, April 10, 2023
Time: 11:30 a.m. to 1:30 p.m. EST
Location: Southwick Hall, Room 240.

All interested students and faculty members are invited to attend the defense in person or via remote online access. Those interested in attending remotely should contact the student (Zhengyang_Yang@student.uml.edu) and committee advisor (Zhiyong_Gu@uml.edu) at least 24 hours prior to the defense to request access to the meeting.

Committee:

  • Zhiyong Gu, Research Advisor, Professor, Chemical Engineering, University of Massachusetts Lowell
  • Fanglin Che, Assistant Professor, Chemical Engineering, University of Massachusetts Lowell
  • Kowk-Fan Chow, Associate Professor, Chemistry, University of Massachusetts Lowell

Brief Abstract:

Cu has been extensively studied as electrocatalysts and electrochemical sensors due to its unique chemical and physical properties. This work features the usage of Cu-based nanoneedle array aiming for electrochemical CO2 reduction reaction (CO2RR) and nitrate sensing applications. First, the Cu-based nanoneedle array has been fabricated via a facile electrodeposition method by using anodic aluminum oxide (AAO) membrane. The active surface area can be enhanced via the highly ordered and vertically aligned nanoneedle structure, and the morphology of Cu nanoneedle/nanowire can be adjusted via the deposition current. The one-dimensional nanoneedle structure benefits from a high edge sites density and active facet exposure. The structure analysis was conducted by scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). The potential application of the Cu nanoneedle array was explored for CO2RR with focus on selectivity to C2+ products and nitrate sensing via a Cyclic Voltammetry method. With the nanoneedle array electrode, the electrochemical performance was significantly improved with higher electrochemical surface area, lower charge transfer resistance, and lower onset potential, as compared to the Cu foil electrodes. The preliminary results showed that the surface modification of aminothiol type molecules can enhance the selectivity of C2 products such as ethylene and ethanol at a moderate potential. The sensing of nitrate via the Cu-based nanoneedle array exhibited a high sensitivity compared to the literature works, with a detecting limit to meet the regulation of the U.S. Environmental Protection Agency (EPA). Overall, the Cu-based nanoneedles showed great potential in a wide range of electrochemical catalytic and sensing applications.