Synthesis, characterization and photocatalytic activity of noble metal-modified TiO2 nanosheets with exposed {001} facets

摘要

Pt, Pd, Ag and Au nanoparticles were photodeposited on the {0 0 1} crystal facets of the TiO2 anatase nanosheets. Morphological and surface characterization of the samples as well as photocatalytic activity were studied. The influence of metal precursor concentration used during photodeposition (0.05-0.5%) on size of formed metal nanoparticles together with UV and vis-mediated activity of Pt, Pd, Ag or Au-TiO2 was investigated. Generally, samples obtained by photodeposition of noble metal nanoparticles using their 0.2% precursor solutions revealed highest activity in phenol degradation reaction under visible light (lambda>420 nm). The photoactivity of the as-prepared samples with respect to the modified metal species was ordered Ag congruent to Pd > Au > Pt. TEM analysis showed that photodeposited metal nanoparticles appeared only on {0 0 1} facets of TiO2. The average degradation rate of phenol in the presence of Pd and Ag-TiO2 was 0.5 mu mol dm(-3) min(-1) after 60 min of irradiation under visible light, and was five times higher than that of pure TiO2 nanosheets. (C) 2015 Elsevier B.V. All rights reserved.