Fig. 3: CO₂ photoreduction performance of the CPs.

a Time course of the produced CO for CPs during 5 h experiment performed under visible light (420 nm cut-off filter) in an acetonitrile/water (7:3) mixture using triethanolamine (TEOA) as sacrificial agent and 5 μmol Co (II) bipyridine complexes as a cocatalyst over 5 mg CPs under ~80 KPa of pure CO₂ gas, inset: X-axis enlarged performance of CO evolution. b Average CO evolution rates for CPs with (red bar) or without (green bar) cocatalyst, c Recyclability of N-CPD (yellow bar) and L-CP-D (blue bar) in the photocatalytic CO₂ reduction within five cycles. d Mass spectra of ¹³CO and total ion chromatography (inset) over N-CP-D in the photocatalytic reduction of ¹³CO₂. e In-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) for the photocatalytic reduction of CO₂ over N-CP-D.