Preparation And Photocatalytic Performance Of ZnS/ESM Composites

In this paper, we investigate the synthesis process and photocatalytic performance ofthe ZnS/ESM (eggshell membrane) composites, and study the effects of operationconditions on the photocatalytic activity of ZnS/ESM composites, which will provide atheoretical basis and experiment foundation for ZnS materials to be practically used in thephotocatalytic fields. The main research contents and conclusions are as follows:ZnS/ESM composites were synthesized using ESM from kitchens and industry assupporter and template through liquid impregnation method. The composites werecharacterized by XRD, SEM, EDS, FT-IR and UV-DRS, and the factors influencing on thephotocatalytic performance of ZnS such as raw materials (zinc sources and sulfur sources),cycle indexes of the impregnation, temperature of the impregnation solution andconcentration of the sulfur source solution were studied. Furthermore, the formationmechanism and photocatalytic mechanism of as-obtained ZnS/ESM composites were alsoanalyzed.The research results showed that the formed ZnS nanoparticles with the average sizeabout40nm uniformly distributed on the surface of the egg membrane fibers and were ofcubic zinc blend structure. The crystallinity and the amount of the ZnS loaded on the ESMfibers were lower with the thioacetamide as sulfur source; the crystallinity and the amountof the ZnS loaded on the ESM fibers were significantly improved with the cycle indexes ofthe impregnation increasing; the temperature of the impregnation solution andconcentration of the sulfur source solution had effect on the crystallinity and the amount ofthe ZnS loaded on the ESM fibers, and the loss of ingredient of ESM were increased withthe the temperature of the impregnation solution and concentration of the sulfur sourcesolution increasing; the results showed that the ESM played a role not only as a supporter,but also as a template to participate in the whole process of synthesis of ZnS/ESMcomposites and had significant effect on the nucleation and growth of ZnS nanoparticles;the introduction of ESM enhanced the intensity of light absorption and the stability of theZnS/ESM composites as photocatalyst. Furthermore, the introduction of ESM also made iteasily to recover the photocatalytic nanoparticles. The crystallinity and the amount of the ZnS loaded on the ESM fibers affected significantly on the photocatalytic activity of theZnS/ESM composites.