One-step hydrothermal synthesis of high-performance visible-light-driven SnS2/SnO2 nanoheterojunction photocatalyst for the reduction of aqueous Cr(VI)
One-step hydrothermal synthesis of high-performance visible-light-driven SnS2/SnO2 nanoheterojunction photocatalyst for the reduction of aqueous Cr(VI)
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DOI：
10.1016/j.apcatb.2013.08.006
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发表时间：
2014
影响因子：
22.1
通讯作者：
Y. Zhang;L. Yao;Geshan Zhang;D. Dionysiou;Jing Li;Xi-hua Du
中科院分区：
文献类型：
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作者：
Y. Zhang;L. Yao;Geshan Zhang;D. Dionysiou;Jing Li;Xi-hua Du
一种简单且具有成本效益的一步水热方法，其基于五水合氯化锡（IV）和不同剂量的硫代乙酰胺在水中在190 °C下反应6小时，用于合成组成可调的SnS 2/SnO 2纳米异质结（例如，SnS 2/SnO 2-A、SnS 2/SnO 2-B和SnS 2/SnO 2-C）。在可见光（λ> 420 nm）照射下，以Cr（VI）水溶液为反应物，研究了SnS 2/SnO 2纳米异质结的光催化性能。此外，还比较了SnS 2/SnO 2-B与PM-SnS 2/SnO 2（表示与SnS 2/SnO 2-B组成相同的物理混合SnS 2/SnO 2纳米复合材料）和SnS 2纳米片在不同光催化剂用量下的光催化效率。结果表明：（i）SnS 2/SnO 2纳米异质结的光催化活性与其组成有关，其中SnS 2含量为70 mol%的SnS 2/SnO 2-B具有最高的光催化活性，（ii）在不同的光催化剂用量下，SnS 2/SnO 2-B的光催化活性均高于PM-SnS 2/SnO 2和SnS 2纳米片; 1 mol/L HNO 3洗涤可有效地使光催化剂再生; 4）SnS 2/SnO 2-B在重复使用中表现出良好的光催化稳定性，每次光催化使用后可通过1 mol/L HNO 3-洗涤进行再生; 5）Cr（VI）被还原为Cr（III）。并对SnS 2/SnO 2纳米异质结的形成机理和光催化效果的原因进行了讨论。
A simple and cost-effective one-step hydrothermal method, which was based on the reactions of tin(IV) chloride pentahydrate and different dosages of thioacetamide in water at 190 °C for 6 h, was employed for the synthesis of composition-tunable SnS2/SnO2nanoheterojunctions (e.g., SnS2/SnO2-A, SnS2/SnO2-B and SnS2/SnO2-C). The photocatalytic properties of the as-synthesized SnS2/SnO2nanoheterojunctions were tested by the reduction of aqueous Cr(VI) under visible-light (λ> 420 nm) irradiation. Furthermore, the photocatalytic efficiency of SnS2/SnO2-B was compared with those of PM-SnS2/SnO2(which denotes the physically mixed SnS2/SnO2nanocomposite with the same composition as SnS2/SnO2-B) and SnS2nanoflakes at different dosages of photocatalysts. It was observed that (i) the photocatalytic activities of the as-synthesized SnS2/SnO2nanoheterojunctions depended on their compositions, and SnS2/SnO2-B with 70 mol% SnS2displayed the highest photocatalytic activity; (ii) SnS2/SnO2-B invariably exhibited higher photocatalytic efficiencies than PM-SnS2/SnO2and SnS2nanoflakes at different dosages of photocatalysts; (iii) the washing with 1 mol/L HNO3can effectively regenerate the used photocatalyst; (iv) SnS2/SnO2-B exhibited good photocatalytic stability in reuses, with regeneration by 1 mol/L HNO3-washing after each cycle of photocatalytic use; and (v) Cr(VI) was reduced to Cr(III). The possible formation mechanism of SnS2/SnO2nanoheterojunctions and the reasons accounting for the photocatalytic results were also discussed.