Investigations of Interfacial Electric Field on Reduced‐Graphene‐Oxide‐Supported Molybdenum Oxide @ Silver Phosphate Ternary Hybrid Composite: Highly Efficient Visible‐Light‐Driven Photocatalyst

• Published in: ChemistrySelect (Weinheim) 2018-09, Vol.3 (34), p.9920-9932
• Main Authors: Dhanabal, Rengasamy, Shafi, Parrasseri Muhammed, Arun, Thirumurugan, Velmathi, Sivan, Hussain, Shamima, Bose, Arumugam Chandra
• Format: Article
• Language: English
• Subjects: Interfacial electric field; Organic dyes; Photocatalyst; RGO-MoO3@Ag3PO4
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.201801158

Reduced graphene oxide supported molybdenum oxide @ silver phosphate (RGO‐MoO3@Ag3PO4) ternary hybrid composite was prepared by simple mixing of RGO supported MoO3 nanorods into Ag3PO4 nanosphere. Upon visible light exposure, the photocatalytic degradation of MB revealed that the 30 wt.% RGO‐MoO3@Ag3PO4 photocatalyst led to 2.9 times higher activities than pure Ag3PO4, 6.2 and 8.7 times compared to RGO‐MoO3 and pure MoO3, respectively. Degradation of MB using 30 wt.% RGO‐MoO3@Ag3PO4 is 2.9 and 15 times higher compared to RhB and MO respectively. The downward band bending of Ag3PO4 at the interface of RGO‐MoO3@Ag3PO4 was investigated based on the electric field formed. The formed electric field at the interface of RGO‐MoO3@Ag3PO4 is found to be 50 mV which avoids the recombination rate of electron‐hole pairs at the interfaces. This formed electric field promotes the higher separation efficiency of electrons‐holes pairs and longer life time of photoexcited electrons in the RGO‐MoO3@Ag3PO4 resulting higher efficiency and stability. RGO act as an electron acceptor and transporter during charge transfer process between MoO3 and Ag3PO4. Figure shows charge transfer processes in the RGO‐MoO3@Ag3PO4 hybrid nanocomposites under visible light irradiation. Electrons are excited from valence to conduction band of both MoO3 and Ag3PO4, and then the electrons at conduction band of Ag3PO4 are transferred to RGO sheet. RGO sheet accepts electrons and transfers to the conduction band of MoO3. Holes at valence band of MoO3 and Ag3PO4 directly oxidise dye molecules. The formed radicals (O2.−and .OH) effectively degrade dye molecules under visible light irradiation.