Realizing highly efficient utilization of solar energy for solving problems of environmental pollution and energy shortage has attracted increasing attention. Herein, Z-scheme two-dimensional (2D)/2D NiCo-LDH/g-C3N4 (LDH/CN) heterojunction composites were synthesized, which showed enhanced photocatalytic performance for tetracycline hydrochloride (TC) degradation and hydrogen (H2) generation under visible light irradiation. A 2D/2D heterojunction structure was formed between NiCo-LDH nanosheets (LDH) and g-C3N4 (CN), which was beneficial for the effective separation of photogenerated charge carriers. The active species of hydroxyl (˙OH), superoxide (˙O2−) and hole (h+) radicals contributed to TC photodegradation. The optimum photocatalyst showed a remarkably enhanced photocatalytic capability with a hydrogen generation rate of 451.7 μmol g−1 h−1. The improved photocatalytic activities may be attributed to the synergistic effects of the increased absorption of visible light, the separation efficiency of carriers and the 2D/2D heterostructure. A Z-scheme photocatalytic mechanism was proposed for the LDH/CN composite, showing dual advantages of a high redox ability and efficient charge carrier separation.
