Visible light responsive MoS2/Ag@WO3/EG photoanode with highly stable Z-scheme induced circular electron motion pioneered by Exfoliated graphite for bisphenol a photoelectrodegradation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-05, Vol.464, p.142462, Article 142462
• Main Authors: Mafa, Potlako J., Malefane, Mope E., Opoku, Francis, Mamba, Bhekie B., Kuvarega, Alex T.
• Format: Article
• Language: English
• Subjects: Bisphenol A; Exfoliated graphite; MoS2/Ag@WO3 Heterojunction; Photoelectrocatalytic
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.142462

[Display omitted] •MoS2/Ag@WO3/EG photoanode was constructed with superb electrocatalytic activity for BPA under visible light.•Z-scheme mechanism was proposed from trapping experiments, XPS and DFT calculations.•Exfoliated graphite pioneered the circular motion of charge transfer which induced high charge separation efficiency.•●O2– >●OH > h+ were all involved in BPA degradation with a surface renewable photoanode. The alarming issue of endocrine disrupting chemicals increase in aquatic environment has heightened concerns about their potential impact on human health and ecosystem. Taking cognizance of this, the current investigation focused on fabrication of effective and efficient photoanode (MoS2/Ag@WO3/EG) from molybdenum disulphide/silver@tungsten trioxide (MoS2/Ag@WO3) photocatalyst and exfoliated graphite (EG) for the photoelectrocatalytic degradation of bisphenol A (BPA). The characterization results and Density Functional Theory (DFT) calculations together affirmed a strong interfacial contact and charge transfer direction at the interface of the materials for substantial promotion of charge separation and increased photoelectrocatalytic performance. The charge separation was further increased by EG’s “give-accept or redistribution” strategy of the charge at the interface that allowed circular motion of electrons in the formed Z-scheme heterostructure. The MoS2/Ag@WO3/EG photoanode exhibited the highest photoelectrocatalytic activity for BPA degradation with efficiency of 100% at optimum experimental conditions. The high degradation efficiency was attributed to uplifted visible light absorption emanating from EG surface plasmon resonance (SPR) contribution, formation of Z-scheme for efficient charge separation, and high stability of the photoanode, which possessed renewable surface. Moreover, scavenger experiments confirmed the participation of all the radicals (●O2– >●OH > h+) in BPA decomposition. Based on XPS, DFT, and radical experiments, the Z-scheme mechanism was proposed, and this work shed light on the production of highly effective house-made photoanode for photoelectrocatalytic processes, thus this can be a good fit in the industrial setup for degradation of other pollutants like microbials.