2017 | "Non-stoichiometric SnS microspheres with highly enhanced photoreducti…
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작성자 관리자 / 작성일2018-02-21 / 조회872회본문
Title : Non-stoichiometric SnS microspheres with highly enhanced photoreduction efficiency for Cr(VI) ions
Authors : Ali Rauf, Md. Selim Arif Sher Shah, Jun Young Lee, Chan-Hwa Chung, Jong Wook Bae and Pil J. Yoo
Journal : RSC Advances
Vol/No/Page : 49/7/30533-30541
DOI : 10.1039/C7RA03854B
Abstract :
Self-doped semiconductors have recently attracted extensive interest as highly efficient photocatalytic materials because the electronic properties can be modulated without sacrificing the chemical stability of the parent material. In this report, we report the facile synthesis of Sn2+ self-doped SnS microparticles via a simple template-free hydrothermal route. Because of the ability to successfully tune the band structure while minimizing defect generation, self-doped SnS could potentially serve as an efficient photocatalyst of wastewater. Here, Sn2+ self-doping results in insertion of an energy level slightly below the conduction band of SnS, thereby decreasing the photoexcitation energy. Furthermore, dopant sites can act as charge trapping sites, which can consequently minimize problematic charge recombination. Synthesized materials were characterized by various spectroscopic, microscopic, and surface characterization techniques, all of which confirmed the formation of self-doped SnS. The Sn2+ selfdoped SnS photocatalyst successfully reduced carcinogenic Cr(VI) to the water-insoluble Cr(III) form under visible light illumination. The best photocatalytic efficiency was obtained from an optimal balance between increased numbers of trapping sites leading to longer charge carrier lifetime, and decreased distance between trapping sites, favoring charge recombination. We anticipate that similar methodologies can be applied to other non-stoichiometric semiconducting photocatalysts with tunable electronic properties and enhanced photocatalytic efficiency.
Authors : Ali Rauf, Md. Selim Arif Sher Shah, Jun Young Lee, Chan-Hwa Chung, Jong Wook Bae and Pil J. Yoo
Journal : RSC Advances
Vol/No/Page : 49/7/30533-30541
DOI : 10.1039/C7RA03854B
Abstract :
Self-doped semiconductors have recently attracted extensive interest as highly efficient photocatalytic materials because the electronic properties can be modulated without sacrificing the chemical stability of the parent material. In this report, we report the facile synthesis of Sn2+ self-doped SnS microparticles via a simple template-free hydrothermal route. Because of the ability to successfully tune the band structure while minimizing defect generation, self-doped SnS could potentially serve as an efficient photocatalyst of wastewater. Here, Sn2+ self-doping results in insertion of an energy level slightly below the conduction band of SnS, thereby decreasing the photoexcitation energy. Furthermore, dopant sites can act as charge trapping sites, which can consequently minimize problematic charge recombination. Synthesized materials were characterized by various spectroscopic, microscopic, and surface characterization techniques, all of which confirmed the formation of self-doped SnS. The Sn2+ selfdoped SnS photocatalyst successfully reduced carcinogenic Cr(VI) to the water-insoluble Cr(III) form under visible light illumination. The best photocatalytic efficiency was obtained from an optimal balance between increased numbers of trapping sites leading to longer charge carrier lifetime, and decreased distance between trapping sites, favoring charge recombination. We anticipate that similar methodologies can be applied to other non-stoichiometric semiconducting photocatalysts with tunable electronic properties and enhanced photocatalytic efficiency.
