Polymeric iron phthalocyanine/g-C3N4 composite catalyst by mechanical force enhanced stripping and recombination for solar-induced contaminant degradation and CO2 reduction

[Display omitted] •The visible light range of g-C3N4 was broadened by FePPc sensitization.•FePPc and g-C3N4 could be stripped mechanically, be recompounded and exposed more active sites by ball milling.•The π-π stacked interaction between FePPc and g-C3N4 contributed to the faster electron transfer.•FePPc/g-C3N4 can oxidize recalcitrant pollutants deeply and reduce CO2 under solar irradiation.•Provide some insights into the preparation of photocatalysts for environmental and energy applications. Solar light response photocatalysts have been extensively studied to alleviate energy crisis and solve environmental pollution problems. Herein, polymerized iron phthalocyanine (FePPc) was prepared and then compounded with graphitic carbon nitride (g-C3N4) by ball milling to obtain FePPc/g-C3N4 composite photocatalyst. During the ball milling process, FePPc was mechanically exfoliated and compounded with g-C3N4, which the binding mode mainly relied on π-π stacking interaction with each other. Carbamazepine (CBZ) was completely removed within 15 min by FePPc/g-C3N4 under solar irradiation in the presence of peroxymonosulfate (PMS). Moreover, carbon dioxide (CO2) was also effectively reduced in the solar light responsive catalytic system with FePPc/g-C3N4 and the CO yield was 3388.98 µmol/g in 12 h. Compared with small molecule iron phthalocyanine (FePc)/g-C3N4, FePPc/g-C3N4 presented a significantly enhanced photocatalytic oxidation and reduction performance under solar light irradiation. Significantly, the visible light response of composite catalyst has been broadened due to FePPc sensitization, which reaching the near-IR light absorption band. Meanwhile, the compounding of photogenerated electron-hole pairs were efficaciously suppressed originating from the stronger bonding and greater electronic transfer between FePPc and g-C3N4. This work provides an effective basis for improving the utilization of sunlight in wastewater treatment and CO2 reduction.