CuInGaSe nanocrystals for detection of trace amount of water in D₂O (at ppm level)

Abstract

Herein, we describe synthesis of copper indium gallium selenide (CIGS) nanocrystals by sol–gel method at room temperature, and the optimization of In/Ga ratio revealed best results pertained to Cu 0.19 In 0.24 Ga 0.76 Se 2.7 composition. The morphology and crystal structure of these nanocrystals were ascertained from scanning electron microscopy (SEM) and X‐ray diffraction (XRD) studies. These nanocrystals were dispersed in D 2 O‐H 2 O binary mixture and these samples were probed for the presence of H 2 O at ppm level (between 9 to 117 ppm) using fluorescence spectroscopy. The fluorescence intensity at the emission wavelength of 485 nm was found to increase with water content, and hence it operated as an excellent water sensor with a fast response time. It was also noted that observable color change of CIGS dispersion made in ethanol occurred, when trace amount of water was added confirming the water sensing ability of this nanomaterial in different environment. Our reproducible experimental results show that CIGS nanocrystals are promising candidate for water detection in D 2 O at ppm level at room temperature operations. Considering the importance of purity of D 2 O in nuclear reactors, these results are of remarkable importance.