Fig. 3: Van Krevelen plot showing the correlation between H/C ratio and O/C ratio obtained for the organic compounds detected in heterogeneous reaction of NO2 with GA, and GA/NO3−/Fe(III) ([NO3−] = 0.05 mol L−1).

A GA in dark, B GA under light irradiation, C GA/NO3−/Fe(III) ([NO3−] = 0.05 mol L−1) in dark, and D GA/NO3−/Fe(III) ([NO3−] = 0.05 mol L−1) under light irradiation. DBE refers to Double Bond Equivalency.