High photocatalytic activity of g-C3N4/CdZnS/MoS2 3 N 4 /CdZnS/MoS 2 heterojunction for hydrogen production

In an effort to improve the light absorption efficiency of the photocatalyst, g-C3N4 3 N 4 nanosheets with visible light response have been prepared by roasting method, and the g-C3N4/CdZnS 3 N 4 /CdZnS composite catalyst with 2D/0D architecture has been prepared by hydrothermal method after ultrasonic thinning. The g-C3N4/CdZnS/MoS2 3 N 4 /CdZnS/MoS 2 composite catalyst with 2D/0D architecture has been synthesized by secondary hydrothermal method. TEM analysis proves that a close heterogeneous interface has been formed between g-C3N4 3 N 4 and CdZnS, and between CdZnS and MoS2. 2 . The ultraviolet diffuse reflectance spectrum shows that MoS2 2 has a wide light absorption range, which effectively enhances the light utilization ratio of the composite catalyst. The energy band structure diagram and photoelectrochemical test results show that a continuous stepped type II ternary heterojunction is formed among g-C3N4, 3 N 4 , CdZnS and MoS2, 2 , which promotes its separation of photogenerated charges. When the loading mass fraction of g-C3N4 3 N 4 and MoS2 2 is 4%, the hydrogen evolution rate of g-C3N4/CdZnS/MoS2 3 N 4 /CdZnS/MoS 2 composite catalyst is 57.02 mmol g- 1 h- 1 under visible light, which is exceeding 20% that of g-C3N4/CdZnS 3 N 4 /CdZnS and 4.79 times and 44.9 times higher than that of CdZnS and g-C3N4, 3 N 4 , respectively. The two-dimensional structure of g-C3N4 3 N 4 and MoS2 2 significantly improves the stability of the composite catalyst. This work offers feasible ways for ternary heterogeneous photocatalyst construction.