FeCo-LDH/g-C3N4 S-scheme photocatalyst with visible light response and enhanced photocatalytic performance

FeCo-LDH/g-C3N4 S-type heterojunction photocatalysts were successfully prepared by thermal polymerization and electrostatic self-assembly methods. The structure, morphology, light absorption and photoelectrochemical properties of the prepared samples were characterized. The photocatalytic properties of the photocatalysts were evaluated by the degradation of tetracycline (TC) and photocatalytic hydrogen evolution from water splitting under visible light irradiation. The experimental results showed that the photocatalytic properties of FeCo-LDH/g-C3N4 nanocomposites were superior to those of pristine g-C3N4. In addition, when the mass ratio of FeCo-LDH to g-C3N4 was 7:100, the photocatalytic performance of the as-prepared FeCo-LDH(7 %)/g-C3N4 is the optimal. The TC degradation rate of FeCo-LDH(7 %)/g-C3N4 reached 78.0 % within 120 min, which was 2.63 times of that of pure g-C3N4. And the photocatalytic hydrogen evolution of FeCo-LDH(7 %)/g-C3N4 was 107.28 μmol for 4 h, which was 12.68 times that of g-C3N4. The results showed that the as-prepared FeCo-LDH/g-C3N4 nanocomposite photocatalysts have excellent performance in the degradation of TC and the photocatalytic H2 evolution. Meanwhile, the EPR and trapping experiments revealed that OH and O2− played a main role in the photocatalytic TC degradation. The mechanism of photocatalytic TC degradation and hydrogen production of FeCo-LDH/g-C3N4 nanocomposite photocatalysts was also discussed.