title: Visible light induced H2PO(4)(-) removal over CuAlO2 catalyst.
abstract: The delafossite CuAlO(2) is successfully used for the visible light driven H(2)PO(4)(-) reduction. It is prepared from the nitrates decomposition in order to increase the ratio of reaction surface per given mass. CuAlO(2) is a narrow band gap semiconductor which exhibits a good chemical stability with a corrosion rate of 1.70 μmol year(-1) at neutral pH. The flat band potential (+0.25 V(SCE)) is determined from the Mott-Schottky characteristic. Hence, the conduction band, positioned at (-1.19 V(SCE)), lies below the H(2)PO(4)(-) level yielding a spontaneous reduction under visible illumination. The photocatalytic process is investigated under mild conditions and 30% conversion occurs in less than ~6h with a quantum efficiency of 0.04% under full light. The concentration decreases by a factor of 39% after a second cycle. The photoactivity follows a first order kinetic with a rate constant of 6.6 × 10(-2)h(-1). The possibility of identifying the reaction products via the intensity-potential characteristics is explored. The decrease of the conversion rate over illumination time is due to the competitive water reduction.
authors.affiliation: Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry, (U.S.T.H.B), BP 32, 16111 Algiers, Algeria.
authors.forename: N
authors.initials: N
authors.lastname: Benreguia
authors.forename: S
authors.initials: S
authors.lastname: Omeiri
authors.forename: B
authors.initials: B
authors.lastname: Bellal
authors.forename: M
authors.initials: M
authors.lastname: Trari
mesh_terms: D000465:Algorithms; D000537:Aluminum Oxide / Q000737:chemistry*; D002384:Catalysis; D002412:Cations; D002623:Chemistry Techniques, Analytical; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D010756:Phosphoric Acids / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods
chemical_list: D002412:Cations; D007477:Ions; D010756:Phosphoric Acids; D014874:Water Pollutants, Chemical; D014867:Water; D003300:Copper; C030242:phosphoric acid; D000537:Aluminum Oxide