Revealing the Intrinsic Restructuring of Bi 2 O 3 Nanoparticles into Bi Nanosheets during Electrochemical CO 2 Reduction.
Beatriz Ávila-BolívarMauricio Lopez LunaFengli YangAram YoonVicente MontielJosé Solla GullonSee Wee CheeBeatriz Roldan CuenyaPublished in: ACS applied materials & interfaces (2024)
Bismuth is a catalyst material that selectively produces formate during the electrochemical reduction of CO 2 . While different synthesis strategies have been employed to create electrocatalysts with better performance, the restructuring of bismuth precatalysts during the reaction has also been previously reported. The mechanism behind the change has, however, remained unclear. Here, we show that Bi 2 O 3 nanoparticles supported on Vulcan carbon intrinsically transform into stellated nanosheet aggregates upon exposure to an electrolyte. Liquid cell transmission electron microscopy observations first revealed the gradual restructuring of the nanoparticles into nanosheets in the presence of 0.1 M KHCO 3 without an applied potential. Our experiments also associated the restructuring with solubility of bismuth in the electrolyte. While the consequent agglomerates were stable under moderate negative potentials (-0.3 V RHE ), they dissolved over time at larger negative potentials (-0.4 and -0.5 V RHE ). Operando Raman spectra collected during the reaction showed that under an applied potential, the oxide particles reduced to metallic bismuth, thereby confirming the metal as the working phase for producing formate. These results inform us about the working morphology of these electrocatalysts and their formation and degradation mechanisms.
Keyphrases
- ionic liquid
- visible light
- oxide nanoparticles
- reduced graphene oxide
- electron microscopy
- gold nanoparticles
- single cell
- room temperature
- highly efficient
- quantum dots
- metal organic framework
- label free
- human health
- molecularly imprinted
- cell therapy
- high intensity
- walled carbon nanotubes
- electron transfer
- risk assessment
- solid state
- solid phase extraction
- simultaneous determination
- carbon dioxide