Fig. 1 XRD patterns of samples prepared at different conditions (a) Sample PI (1:1) and its precursor PMDA and melem; (b) Samples PI (1:1), PI (2:1), PI (1:2), and PI (1:2)-120

Fig. 2 TEM images of sample PI (1:2) (a, b) and sample PI (1:2)-120 (c, d)

Fig. 3 XPS spectra of different samples (C1s)(a-d), and structural illustration of PI sample (e) (different colors of C atoms correspond to XPS spectra) (a) PI (1:1); (b) PI (1:1)-120; (c) PI (1:2); (d) PI (1:2)-120; Colorful figures are available on website

Fig. 4 O2-TPD (a), UV-Vis diffuse reflectance spectra (b) and photocurrent profiles (c) of different samples Colorful figures are available on website

Fig. 5 Nitrogen oxide radical detection and catalytic mechanism analysis (a) FT-IR spectra of PI (1:2) and PI (1:2)-120; (b) In situ FT-IR spectra of PI (1:2)-120 illuminated in air; (c) Absorption intensity versus time for catalyst suspensions with 4 mmol/L HMF added

Fig. 6 Possible structural changes in PI catalysts before and after H2O2 treatment and their possible mechanism for catalytic oxidation of HMF

Fig. S1 Normalized decay of the transient photocurrent of PI (1:2) and PI (1:2)-120 samples

Fig. S2 Mott-Schottky spectra (a, b), estimated bandgap based on UV-Vis diffuse reflectance (c), valence band position estimation based on VB XPS (d), schematic diagram of catalyst energy band position (e) of different samples

Fig. S3 (a) Comparison of absorbance of methanone after testing the superoxide radical reaction; (b) Comparison of the yields of OH; (c) Comparison of the yields of H2O2 Experimental condition: 50 mg Catalyst, 30 mL deionized water, atmospheric pressure: air atmosphere, 15 ℃, reaction time: 1 h (Fig. S3(a) concentration of NBT solution=0.2 mmol/L)

Fig. S4 Cycling experiments of PI(1 : 2)-120 catalyst Experimental conditions: 50 mg PI(1:2)-120 catalyst, 400 nm LED lamp, 30 mL 0.67 mmol/L HMF aqueous solution, atmospheric pressure air, reaction for 12 h at 15 ℃