• Sfirloaga, Paula

Abstract

<jats:p>In this study series of CdxZn1-xS solid solutions with different amounts ofCd and Zn were synthesized by the hydrothermal treatment of aqueoussolutions containing CdCl2, Na2S ? 9H2O and ZnSO4 ? 7H2O. The aim was toexamine the influence of Zn concentration and processing conditions(hydrothermal temperature and duration) on the structure of the obtainedpowders and their photocatalytic activity (in water splitting process). Theobtained photocatalysts (with and without Pd co-catalyst) were analysed byX-ray diffraction (XRD), atomic absorption spectroscopy (AAS),ultraviolet-visible spectroscopy (UV-VIS), scanning electron microscopy(SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET)method and gas chromatography (GC). The XRD results confirmed thecrystallinity of the compounds and transition from hexagonal to cubic phasewith increasing Zn content. Complete transformation from hexagonal to cubicphase did not take place, and both phases were present in almost allsamples. BET analysis showed the importance of the pore distribution andpore size, especially in the case of photocatalysts with different durationtreatment. GC measurements of the photocatalysts without and with Pdco-catalyst confirmed the production of hydrogen for all tested compounds.The best photocatalytic performance was achieved by the sample Zn50230/72-Pdprepared at 230?C, for 72 hours, with 50% Zn and in the presence of Pdco-catalyst. The synthesis implied neither stabilizer nor organic compound.</jats:p>

Topics

• pore
• compound
• phase
• scanning electron microscopy
• x-ray diffraction
• organic compound
• Hydrogen
• transmission electron microscopy
• gas chromatography
• atomic absorpion spectrometry