PW11Co/Ag3PO4/WS2 ternary composites with enhanced photocatalytic performance for the degradation of organic pollutants under visible light

• Published in: Materials letters 2023-11, Vol.351, p.135048, Article 135048
• Main Authors: Wang, Enhui, Ding, Shan, Zhang, Junqiu, Yu, Linqun, Zhang, Yan, Jiang, Chunjie, Yang, Guang-Sheng
• Format: Article
• Language: English
• Subjects: Composite materials; Photodegradation; Polyoxometalates; Surfaces
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2023.135048

The PW11Co/Ag3PO4/WS2 composite exhibits excellent photocatalytic performance for the degradation of organic pollutants. Radical trapping experiments show that holes and superoxide radicals play a major role in the photocatalytic degradation process. A Z-scheme heterojunction mechanism was proposed for the progress of photocatalytic degradation. [Display omitted] •PW11Co/Ag3PO4/WS2 has excellent photocatalytic properties under visible light.•Free radical trapping experiments demonstrate that h+, O2− are reactive species.•PL spectroscopic tests show high separation efficiency of photogenerated carriers.•A Z-scheme heterojunction mechanism was proposed based on energy band structure. A new composite material PW11Co/Ag3PO4/WS2 was designed and synthesized using cobalt-substituted Keggin-type phosphotungstic acid (PW11Co), silver phosphate (Ag3PO4) and tungsten sulfide (WS2) as experimental raw materials. Under simulated visible light, PW11Co/Ag3PO4/WS2 can efficiently degrade various dye molecules, and the removal rate is above 90% during 1 h (50 mg catalyst, 100 mL 20 mg/L of dyes). Excellent photocatalytic performance is attributed to high separation efficiency of the photogenerated carriers, which was proved by PL spectroscopy, transient photocurrent tests and the Nyquist diagram of PW11Co/Ag3PO4/WS2. The free radical trapping experiment showed that the hole (h+) and superoxide radical (O2−) were the main active species in the photocatalytic reaction. Based on energy band theory, a reasonable Z-scheme heterojunction mechanism was proposed for the progress of photocatalytic degradation.