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Enhanced visible-light-driven porous O/P-C 3 N 4 for persulfate photoactivation to remove refractory organic pollutants (bisphenol A and 2-mercaptobenzothiazole) and depolymerize lignin to vanillic acid and various gases. [Display omitted] • Surface electron density on HAPA-CN was enhanced by oxygen and phosphorus doping. • 0.05 HAPA-CN exhibits excellent performance for persulfate photoactivation to remove BPA and MBT. • In-depth exploration of the intermediate products during the photodegradation. • Remarkable sodium lignosulfonate conversion and vanillic acid selectivity achieved. • The transformation of sodium lignosulfonate synergistically produces a variety of gases (H 2 , CO, CH 4 , C 2 H 4 , C 2 H 6). In this research, an enhanced visible light response of oxygen and phosphorus-doped porous g-C 3 N 4 (HAPA-CN) was prepared by thermo-polymerization of urea, hydroxyacetic acid and phytic acid. Its internal structure was verified by solid-state nuclear magnetism (NMR) and secondary ion mass spectrometry (SIMS). The surface electron density on HAPA-CN was enhanced by the inclusion of oxygen and phosphorus. The boosted photocatalytic activity was attributed to the high spectral utilization of sunlight and meliorated charge separation efficiency. The experimental results showed that the 0.05 HAPA-CN/persulfate (PS) system exhibited a higher efficiency in the photodegradation process of bisphenol A (BPA) and 2-mercaptobenzothiazole (MBT). Compared with ordinary g-C 3 N 4 , the integration of photocatalysis and persulfate oxidation led to an increase in the removal of BPA and MBT pollutants, which increased by 68.11 and 11.18 times, respectively. 0.05 HAPA-CN also exhibited a certain photodegradation of BPA under long-wavelength light irradiation such as blue, green, and red light. In the photocatalytic conversion of sodium lignosulfonate (SL), the 0.05 HAPA-CN/PS system achieved a maximum yield of 134.34 mg/g SL vanillic acid at 30 min, which was significantly better than that of g-C 3 N 4. Synergistic gas production (H 2 , CO, CH 4 , C 2 H 4 , C 2 H 6) was also significantly enhanced. Combined with theoretical calculations, the mechanism was also analyzed. This work provides new insights for exploring high efficiency photocatalyst that combine porous structure, oxygen and phosphorus co-doping and PS activation technology for removal of organic pollutants and lignin valorization. [ABSTRACT FROM AUTHOR]