N,N-dibenzyl dithiocarbamato silver(I) as precursor for silver sulfide nanophotocatalysts for photocatalytic degradation of rhodamine 6G and trypan blue dyes

Abstract

N,N-dibenzyl dithiocarbamate silver(I) was synthesized and characterized by spectroscopic techniques and single crystal X-ray crystallography. The complex crystallizes in the trigonal space group P31 to form a one-dimensional, chain-like polymeric structure connected by Ag-Ag argentophilic and Ag-S interactions. The complex was used as single source precursor and thermolyzed at 120, 160 and 200 °C in 1-dodecanethiol to prepare silver sulfide nanoparticles (AgS-120, AgS-160 and AgS-200). TEM images showed quasi-spherical nanoparticles with average particle sizes of 4.0, 5.4 and 5.5 nm for nanoparticles prepared at 120, 160 and 200 °C, respectively, with optical band gaps of 3.76, 3.81 and 3.71 eV. The as-prepared silver sulfide nanoparticles potential as photocatalysts were evaluated using rhodamine 6G and trypan blue under irradiation. The photocatalytic degradation efficiency of 42.4% (k = 3.03 × 10−3), 41.9% (k = 2.73 × 10−3) and 56.7% (k = 4.16 × 10−3) for rhodamine 6G dye and 35.4% (2.94 × 10−3), 49.7% (3.87 × 10−3) and 16.9% (9.0 × 10−4) for trypan blue dye were obtained in the presence of AgS-120, AgS-160 and AgS-200, respectively. The kinetics and mechanism of photocatalytic reaction show that the dye degradation in the presence of the as-prepared nanoparticles follow pseudo-first order kinetics.