Construction of dual S-scheme heterojunction with ordered asymmetric structure for enhancing antibiotic degradation

The disordered distribution of components in heterojunctions increases the probability of internal recombination of charge carriers, consequently diminishing photocatalytic efficiency. This study presents the design of a dual Sscheme heterojunction of TiO2/hematite/CNMn with a customized stacking sequence as a photocatalyst, improving charge carrier separation. This catalyst demonstrates the capability to degrade H2O2 and achieve selfpropulsion, with a movement velocity of 47.8 +/- 4.6 mu m/s under 0.1 % H2O2 and light conditions. The autonomous movement of the catalyst provides a stirring effect and enhances the mass transfer coefficient. Additionally, the synergistic effect of photocatalysis and Fenton oxidation provides multiple pathways for the generation of free radicals. The combination of these advantageous properties enables the synthesized catalyst to degrade 89.2 +/- 1.3 % of antibiotics within 30 min. This research highlights how ordered structure and mass transfer efficiency impact degradation processes. The fabricated heterojunction micromotor demonstrates remarkable durability and effectiveness in breaking down antibiotics.