title: 3 D Co3(PO4)2-Reduced Graphene Oxide Flowers for Photocatalytic Water Splitting: A Type II Staggered Heterojunction System.
abstract: The design, synthesis, and photoelectrochemical characterization of Co3(PO4)2, a hydrogen evolving catalyst modified with reduced graphene oxide (RGO), is reported. The 3 D flowerlike Co3(PO4)2heterojunction system, consisting of 3 D flowerlike Co3(PO4)2and RGO sheets, was synthesized by a one-pot in situ photoassisted method under visible-light irradiation, which was achieved without the addition of surfactant or a structure-directing reagent. For the first time, Co3(PO4)2is demonstrated to act as a hydrogen evolving catalyst rather than being used as an oxygen evolving photoanode. In particular, 3 D flowerlike Co3(PO4)2anchored to RGO nanosheets is shown to possess dramatically improved photocatalytic activity. This enhanced photoactivity is mainly due to the staggered type II heterojunction system, in which photoinduced electrons from 3 D flowerlike Co3(PO4)2transfer to the RGO sheets and result in decreased charge recombination, as evidenced by photoluminescence spectroscopy. The band gap of Co3(PO4)2was calculated to be 2.35 eV by the Kubelka-Munk method. Again, the Co3(PO4)2semiconductor displays n-type behavior, as observed from Mott-Schottky measurements. These RGO-Co3(PO4)2conjugates are active in the visible range of solar light for water splitting and textile dye degradation, and can be used towards the development of greener and cheaper photocatalysts by exploiting solar light.
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), New Delhi -, 110 025, India.|Colloids and Materials Chemistry Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751 013, India.
authors.forename: Alaka
authors.initials: A
authors.lastname: Samal
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), New Delhi -, 110 025, India.|Colloids and Materials Chemistry Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751 013, India.
authors.forename: Smrutirekha
authors.initials: S
authors.lastname: Swain
authors.affiliation: Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata, 700 064, India.
authors.forename: Biswarup
authors.initials: B
authors.lastname: Satpati
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), New Delhi -, 110 025, India.|Colloids and Materials Chemistry Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751 013, India.
authors.forename: Dipti Prakasini
authors.initials: DP
authors.lastname: Das
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), New Delhi -, 110 025, India.
authors.forename: Barada Kanta
authors.initials: BK
authors.lastname: Mishra
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D055668:Photochemical Processes; D014867:Water / Q000737:chemistry*
chemical_list: D010087:Oxides; D010710:Phosphates; D014867:Water; D003035:Cobalt; D006108:Graphite
keywords: Cobalt phosphate; Reduced graphene oxide; nanoparticles; photochemistry; water splitting