Laser Photochemistry Laboratory

203. Dual-laser pulse-patterned α-Co(OH)2/rGO heterointerface for accelerated water oxidation and surface phase-transition via in-situ Raman spectroscopy
Yeryeong Lee , Jayaraman Theerthagiri , Ahreum Min , Cheol Joo Moon, Myong Yong Choi*

Vol, Part
Available online (2023)
Publication Year

26 September 2023
IF(2022): 14.6
JCR: 94.6%
2019R1A6C1010042, 2021R1A6C103A427, 2022R1A2C2010686, 2022R1A4A3033528, 2021R1I1A1A01060380, 2019H1D3A1A01071209

The dynamic surface reconstruction of electrodes is a legible sign to understand the deep phase-transition mechanistic and electrocatalytic origin during the oxygen evolution reaction (OER). Herein, we report a dual-laser pulse-patterned heterointerface of α-Co(OH)2 and reduced graphene oxide (rGO) nanosheets via pulsed laser irradiation in liquid (PILL) to accelerate OER kinetics. α-Co(OH)2 was formed from the OH− ions generated during the PILL of GO at neutral pH. Co2+ modulation in tetrahedral coordination sites benefits as an electrophilic surface for water oxidation. Few d-vacancies in Co2+ increase its affinity toward oxygen, lowering the energy barrier and generating many CoOOH and CoO2 active sites. rGO with an ordered π-conjugated system aids the surface adsorption of OOH*, O*, and OH* during OER. α-Co(OH)2 surface phase-transition and OER mechanistic steps occurred via phase-reconstruction to CoOOH and CoO2 reactive intermediates, uncovered using in situ electrochemical–Raman spectroscopy. Our findings in the dual-laser pulse strategy and the surface reconstruction correlation in active OER catalysts pave the path for paramount in multiple energy technologies.