<p>Boron carbon nitride (BCN) is a promising adsorbent for removing antibiotics in aquatic environments. However, its practical application in complex aqueous environments is limited by insufficient resistance to pH fluctuations and ion competition. In this study, a novel Ce₂O₂S-doped tubular boron carbon nitride adsorbent (Ce₂O₂S-TBCN) was synthesized via a straightforward <i>in situ</i> temperature-controlled self-assembly method. As the temperature increased from 700 to 1000 °C, the carbon derived from P123 improved the flexibility of BCN and facilitated sulfur retention from Ce(SO₄)₂, leading to the formation of Ce₂O₂S. During this process, interactions between B-OH groups and Ce₂O₂S particles induced the bending of the lamellar structure, ultimately forming a tubular morphology that increased the specific surface area by a factor of 2.8. This structural modification, combined with the incorporation of Ce₂O₂S, synergistically increased the adsorption capacity of Ce₂O₂S-TBCN by 58.9% compared to pristine BCN. The adsorption kinetics of tetracycline by Ce₂O₂S-TBCN followed a pseudo-second-order kinetic model. Isotherm analysis revealed a transition from multilayer to monolayer adsorption as the adsorbent dose increased. The spontaneous and exothermic adsorption process was verified by thermodynamic analysis. Moreover, Ce₂O₂S-TBCN demonstrated remarkable stability under ion coexistence conditions and across a wide pH range, with its performance declining by only 2.4% after 10 cycles. This exceptional stability was attributed to multiple adsorption forces, including hydrogen bonding, Lewis acid-base interactions, and M-π complexation. Ce₂O₂S-TBCN with high adsorption capacity and resistance to interference holds great potential for application in complex aquatic environments.</p>