(Ho, Yb) co-doping effects on structural, optical, photocatalytic and thermal properties of TiO2 NPs prepared by hydrothermal approach

Abstract

TiO₂ nanoparticles with lanthanide dopant's concentration Ho (1 %) and Yb (1, 3 %) were successfully produced by hydrothermal method utilizing titanium isopropoxide, holmium nitrate pentahydrate and ytterbium nitrate pentahydrate as precursors. Produced nanoparticles were analyzed using structural (XRD, FTIR), microstructural (FESEM, EDX), optical (UV–visible, PL), photocatalytic and thermal (TGA, DTG) characterization tools. XRD indicated that TiO₂ and (Ho, Yb) co-doped TiO₂ nanoparticles have anatase phase. The crystallite size, micro-strain, lattice constant and dislocation density were calculated through XRD data. Optical studies revealed bandgap, urbach energy, refractive index, extinction coefficient, optical conductivity and PL emission wavelength. Photocatalytic activity predicted the photodegradation of Rhodamine Band Malachite Green dyes as examined through visible light absorption, and indicated that degradation rate of photocatalyst enhances as (Ho, Yb) doping concentration increases in TiO₂ NPs. Thermal analysis was carried out to estimate weight loss during different phases, and parameters such as activation energy, entropy, enthalpy and Gibb's free energy.