Transition Metal-Based Electrocatalysts for Electrochemical Water Splitting Influenced by Cerium
Date10th Jul 2023
Time02:30 PM
Venue Through Google Meet: https://meet.google.com/ohk-qfwd-vik
PAST EVENT
Details
Electro-catalysis of water is important for the purpose of hydrogen production. This is necessary for spurring the growth of hydrogen economy around the world. However typically there is a challenge of overpotential during electro-catalysis which leads to efficiency losses and lower current density. In my previous research work [1], cerium nickel-based electrocatalyst was electrodeposited onto a stainless steel substrate using CV technique and tested in an alkaline medium under ambient conditions. This under-performs for HER whereas it shows excellent performance for OER. In my present study, a rapid firing/flame heat treatment (a simple route involving quicker, economical, and minimal resources) was used to heat-treat (under well characterized flame at different flame exposure times) electrodeposited ceria-nickel based catalyst onto the stainless steel substrate. Flame heat-treatment brings in material morphological changes and creates defects in ceria-nickel based electrocatalyst that participates in HER because the material standalone condition does not promote lower overpotential for HER. The post heat treated samples when tested for HER Figure (a) in an alkaline medium showed a significant reduction in over potential (at the optimized flame exposure time of two minutes forty-five seconds) to 185 mVdec-1, a current density of 100mAcm-2 was achieved at 440 mV vs RHE. It was also found that the current density further increases after 24 hours of the stability test. The post heated samples show poor performance in OER Figure (b), Figure (c) records the CV for full cell water splitting reactions (to test the materials bifunctionality) in an alkaline medium, it was found that the electrodeposited sample exposed to the flame for 180 s shows the excellent performance in both half reactions.
Speakers
Ms. Priyanka Swarnkar (ME15D059)
Department of Mechanical Engineering