Crystal facets engineering and rGO hybridizing for synergistic enhancement of photocatalytic activity of nickel disulfide.
Crystal facets engineering and rGO hybridizing for synergistic enhancement of photocatalytic activity of nickel disulfide.
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DOI：
10.1016/j.jhazmat.2019.121402
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发表时间：
2020-02
影响因子：
13.6
通讯作者：
Yan Liang;Yong Yang;Keng Xu;Ting Yu;Qing Yang;Pengyuan Shi;C. Yuan
中科院分区：
文献类型：
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作者：
Yan Liang;Yong Yang;Keng Xu;Ting Yu;Qing Yang;Pengyuan Shi;C. Yuan
晶面工程和石墨烯杂化是近年来提高半导体光催化剂光催化活性的有效手段。然而，这些努力大多集中在金属氧化物上。本文首次研究了金属硫化物NiS 2的晶面对光催化活性的影响。结果表明，与{100}-faceted NiS 2纳米晶相比，{111}-faceted NiS 2纳米晶在降解水中各种典型污染物时表现出更好的光催化活性.此外，通过与rGO纳米片杂化，{111}面NiS 2纳米晶的光催化活性得到进一步提高，从而使重金属六价铬和有机染料完全降解。通过理论计算和实验表征，对光催化机理进行了详细的研究。结果表明，Ni端和S端的{111}晶面的表面能均远高于{100}晶面，表明{111}晶面更活跃。此外，rGO杂化可以实现光生电子和空穴的有效分离。研究结果为进一步开发高效金属硫化物光催化剂提供了重要指导。
Crystal facets engineering and graphene hybridizing have been proved to be effective means to improve the photocatalytic activities of semiconductor photocatalysts in recent years. However, most of these efforts are concentrated in metal oxides. In the present study, crystal facets effect on the photocatalytic activity of metal sulfide NiS2was studied for the first time. It was found that the {111}-faceted NiS2nanocrystals showed improved photocatalytic activity in the degradation of various typical pollutants in water compared with {100}-faceted NiS2nanocrystals. Moreover, through hybridizing with rGO nanosheets, the photocatalytic activity of the {111}-faceted NiS2nanocrystals can be further improved, resulting in the complete degradation of heavy metal hexavalent chromium and organic dyes. The photocatalytic mechanism was studied in detail through theory calculation and experimental characterization. It was found that both the surface energies of Ni-terminated and S-terminated {111} facets were much higher than that of {100} facets, indicating that {111} facets were more active. Besides, rGO hybridizing can realize the effective separation of photogenerated electrons and holes. The results provide important guidance for the further development of efficient metal sulfide photocatalysts.