RESUMO
In this study, TiO2 powder was used as the additive to directly blend with raw bituminous coal and coking coal for preparing modified activated carbon (Ti/AC) by one-step carbonization-activation method. The Ti/AC samples were prepared through blending with different ratios of TiO2 (0-12â wt%) and their desulphurization performance was evaluated. The results show that the desulphurization activity of all Ti/AC samples was higher than that of the blank one, and the highest breakthrough sulphur capacity was obtained at 200.55â mg/g C when the blending ratio of TiO2 was 6â wt%. The Brunauer-Emmett-Temer results show that the micropores were dominant in the Ti/AC samples, and their textual properties did not change evidently compared with the blank one. The X-ray photoelectron spectroscopy results show that the loaded TiO2 could influence the relative content of surface functional groups, with slightly higher content of π-π* transitions groups on the Ti/AC samples, and the relative contents of C=O and π-π* transitions groups decreased evidently after the desulphurization process. The X-ray diffraction results show that the anatase TiO2 and rutile TiO2 co-existed on the surface of the Ti/AC samples. After the desulphurization process, TiO2 phases did not change and Ti(SO4)2 was not observed on the Ti/AC samples, while sulphate was the main desulphurization product. It can be assumed that SO2 could be catalytically oxidized into SO3 by TiO2 indirectly, rather than TiO2 directly reacted with SO2 to Ti(SO4)2.
Assuntos
Poluentes Atmosféricos/química , Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Dióxido de Enxofre/química , Titânio/química , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/isolamento & purificação , Dióxido de Enxofre/análise , Dióxido de Enxofre/isolamento & purificação , Propriedades de SuperfícieRESUMO
Cu2ZnSnS4 thin films with thicknesses ranging from 0.35 to 1.85 µm and micron-sized grains (0.5-1.5 µm) were synthesized using co-electrodeposited Cu-Zn-Sn-S precursors with different deposition times. Here we have introduced a sputtered CdS buffer layer for the development of CZTS solar cells for the first time, which enables breakthrough efficiencies up to 6.6%.