Photodegradation of phenol red on a Ni-doped niobate/carbon composite

Author(s)

Lanfredi, Silvania ; Nobre, Marcos A. L. ; Moraes, Paula G. P. ; Matos, Juan

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 40, n. 7, p. 10-pg., 2014-08-01.

Abstract

The photocatalytic activity of a new nanostructured Ni-doped niobate KSr2(Ni0.75Nb4.25)O15-delta was studied using the phenol red dye as a test molecule and the influence of amorphous carbon deposits upon the photoactivity of the niobate-based materials was also verified. KSr2(Ni0.75Nb4.25)O15-delta powder was prepared by a high energy ball milling method and the C-KSr2(Ni0.75Nb4.25)O15-delta composite by the partial pyrolysis of the niobate dispersed in a polyester matrix. Materials were characterized by FM spectroscopy and X-ray diffraction (XRD). The diffraction line profile and the refinement of the structural parameters of KSr2(Ni0.75Nb4.25)O15-delta were derived by the Rietveld method. Both samples showed similar phenol red photodegradation under steady-state kinetic conditions. However, amorphous carbon seems to beneficially affect the reaction mechanism which followed first order kinetics. In terms of KSr2(Ni0.75Nb4.25)O15-delta concentration a clear enhancement in the photoactivity of the niobate in the presence of amorphous carbon by a factor 4.7 was found suggesting a synergy effect between both solids. We conclude that C-KSr2(Ni0.75Nb4.25)O15-delta composite can be employed for the photocatalytic degradation of diluted pollutants. (c) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. (AU)

• FAPESP's process: 07/03510-9 - Structural characterization of nanopowders of semiconductor ferroelectric oxides
• Grantee: Silvania Lanfredi
• Support Opportunities: Regular Research Grants