Photocatalysis CO2 cycloaddition requires a catalyst with good light absorption. High CO2 concentration is usually required for high conversion and yield. The CO2 cycloaddition reaction can be accelerated under solar-driven cycloaddition using a Xenon lamp with 320 mW/cm 2 [196]. The N-doped carbon catalyst is an effective photocatalyst for photothermallydriven CO2 cycloaddition .