Facile synthesis of NiTiO3 yellow nano-pigments with enhanced solar radiation reflection efficiency by an innovative one-step method at low temperature

Abstract

Inorganic NiTiO3 nano-pigments have received recent attentions as possible candidates for cool materials to be used in building roofs and facades. In this paper, we have attempted to develop an innovative low temperature pathway (processed at 50 °C) for obtaining NiTiO3 nanocrystals by an ultrasound-assisted wet chemical processing method. Different characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS) were used in order to characterize the size, morphology and optical responses of the obtained NiTiO3 nanoparticles. The crystallite size, particle size distribution range and band gap were found to be 10 nm, in the range of 10–20 nm and 3.72 eV, respectively. UV–Vis–NIR diffuse reflectance spectrum of NiTiO3 nanoparticles exhibited an intense reflection peak at around 580 nm, which is related to the brilliant yellow color of the synthesized nano-pigments. The enhanced reflectance seen in this work is much higher than that reported in similar works indicating these nano-pigments can be used as cool colorants for coating the building with better energy saving performance. Scanning electron microscopy studies indicated a uniform particle shape with a narrow size distribution. We believe that the methodology developed in this work provides a simple, cost-effective, and convenient route for synthesizing a variety of perovskite materials for assembling in nanotechnology.