Abstract: Aiming at the problem of the structural stability and difficulty in decomposition of p-aminobenzoic acid (PABA), its long-term existence could lead to water pollution, we prepared   a three-dimensional layered FeAl-LDH@FeS_x-NBC catalyst based on biochar (BC)  by  using  hydrothermal method, and constructed  photocatalytic degradation system to degrade  PABA in water. The results show that FeAl-LDH@FeS_x is successfully loaded onto biochar doped with N element.  When the catalyst dosage is 0.3 g/L and the  pH=5, the photocatalytic system exhibits the best degradation effect of PABA, with a removal rate of 95.4% after 210 min. After 5 cycle tests,  FeAl-LDH@FeS_x-NBC still has  a high removal rate of PABA,  indicating good repeatable utilization. The main free radicals for  degradation in this system are superoxide radical (O^-₂),  photogenerated hole (h⁺),   light irradiation causes the separation of  photogenerated electrons (e^-) and h⁺ on the catalyst surface,  where e^- is captured by oxygen to form O^-₂ and h⁺ is captured by hydroxide ions to form hydroxyl radical (^.OH),  thereby promoting the generation of active components in  the entire system.

Key words: p-aminobenzoic acid,  , FeAl-LDH@FeS_x-NBC,  , photocatalytic degradation system