Morphology and Luminescence Properties of Cellulose-CNT-BiPO₄:Pr³⁺ Composites

Abstract

The peculiarities of preparation and properties of composites which consist of cellulose matrix, multiwall carbon nanotubes and praseodymium-doped bismuth phosphate nanoparticles are reported. The SEM images show that oxide particles are incorporated into cellulose when their sizes below 100 nm and can pierce out of composite surface in case of bigger particles. The carbon nanotubes are clearly observed only at the regions near oxide particles that can be explained by close adhesion between these components of composites . Chemical element analysis shows the composites of lower content of nanotubes possess better homogeneity from viewpoint of elements distribution. The studied composites reveal intensive luminescence under excitation at 405 and 473 nm. The photoluminescence spectra depend on the PL excitation wavelength and related mostly with cellulose host emission centers. The Pr³⁺-related emission clearly observed only in the case of composites of higher content of nanotubes at direct PL excitation of ³H₄ → ³P₁ + ¹I₆ absorption transitions in praseodymium ions.