Synthesis and characterization of cauliflower-like ZnS microspheres by simple self-assembly method

Cauliflower-like ZnS microspheres comprising ZnS nanoblock-like structures were fabricated by a simple one-step self-assembly method involving a hydrothermal process at 150 C-circle for 10 h using Zn(CH3COO)(2) and Na2S2O3. 5H(2)O starting materials in an aqueous solution. The synthesized samples were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), and Brunauer-Emmett-Teller (BET) analysis. The photocatalysts were evaluated using the photodecomposition of methylene blue under UV light. The aqueous solutions had a pH 7, and exhibited the presence of a suspension of cauliflower-like ZnS microspheres, about 3-5 mu m in diameter constructed of ZnS nanoblocks < 100 nm size. These cauliflower-like ZnS microspheres have a surface area of 22.82 m(2)/g, a pore volume of 0.0252 cm(3)/g, and a pore diameter of 3.77 nm, as determined by BET analysis. The photocatalytic degradation rate followed a pseudo-first-order equation. The kinetic constant (k(1)) of the cauliflower-like ZnS microspheres was 5.11 x 10(-2) min(-1). (C)2014 Elsevier B.V. All rights reserved.