Fig. 3: Monitoring CO₂ reduction/CO oxidation interconversion via electrochemistry.

A The comparative cyclic voltammograms of 1 mM C1 recorded under 1 atmospheric (atm) CO₂ in DMF (purple trace) and 0.2 M water containing DMF (green trace). B The analogous data measured for 1 mM C2 recorded in DMF (green trace) and 0.45 M water containing DMF (blue trace). The scan rate for these experiments were 0.1 V/s and nBu₄N⁺BF₄^- was used as electrolyte. The comparative cyclic voltammograms of C 0.5 mM C1 under 1 atm Ar (red dotted trace) and 1 atm CO₂ (solid blue trace), and D 0.5 mM C2 under 1 atm Ar (green dotted trace) and 1 atm CO₂ (solid purple trace) in an aqueous solution of pH 6.5. The scan rate for these experiments were 1.0 V/s and Na₂SO₄ was used as electrolyte. The cyclic voltammograms of E 0.5 mM C1 (solid blue trace) and F 0.5 mM C2 (solid purple trace) under 1 atm of 1:1 CO₂/CO mixture. The blank data under analogous conditions are shown in black dotted trace. The scan rate for these experiments were 0.1 V/s and Na₂SO₄ was used as electrolyte. The horizontal arrows in (A–F) signify the initial scan direction. The electrocatalytic CO₂ reduction and CO oxidation responses are represented by the blue and red boxes, respectively.