Highly efficient and recyclable nanocomplexed photocatalysts of AgBr/N-doped and amine-functionalized reduced graphene oxide.
Highly efficient and recyclable nanocomplexed photocatalysts of AgBr/N-doped and amine-functionalized reduced graphene oxide.
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DOI：
10.1021/am5051422
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发表时间：
2014-11
影响因子：
9.5
通讯作者：
Md. Selim Arif Sher Shah;Woo-Jae Kim;Juhyun Park;Do Kyung Rhee;I. Jang;N. Park;J. Y. Lee;P. Yoo-P
中科院分区：
文献类型：
--
作者：
Md. Selim Arif Sher Shah;Woo-Jae Kim;Juhyun Park;Do Kyung Rhee;I. Jang;N. Park;J. Y. Lee;P. Yoo-P
尽管银由于其高的光催化活性而近来引起了相当大的关注，但其在可见光照射下倾向于形成团聚的金属银。因此，光催化活性随时间而降低，不能重复使用。为了克服这一限制，在本工作中，我们将AgBr与氮掺杂（N掺杂）和胺官能化的还原氧化石墨烯（GN）络合。N掺杂和/或胺官能化的石墨烯显示出固有的良好催化活性。此外，胺基可以与银离子发生络合，从而抑制其还原成金属Ag。结果表明，这些复合催化剂在可见光照射下对亚甲基蓝（MB）染料的降解表现出优异的光催化活性。光催化降解亚甲基蓝的实验结果表明，在GN质量分数为0.5%的条件下，光催化降解亚甲基蓝的效果最好，可见光照射50 min，亚甲基蓝的降解率可达99%以上。值得注意的是，络合的催化剂相当稳定，甚至在大于10次重复循环后仍保留其几乎所有的催化活性。此外，该催化剂还可以在可见光照射下有效地分解无色有机污染物2-氯苯酚。详细的实验研究表明，羟基（·OH）自由基在染料降解反应中起着重要的作用。还提出了染料降解的相关机制。
Although silver bromide has recently drawn considerable attention because of its high photocatalytic activity, it tends to form agglomerated metallic silver under the irradiation of visible light. Therefore, photocatalytic activity decreases with time and cannot be applied for repeated uses. To overcome this limitation, in the present work, we complexed AgBr with nitrogen doped (N-doped) and amine functionalized reduced graphene oxide (GN). N-doped and/or amine functionalized graphene shows intrinsically good catalytic activity. Besides, amine groups can undergo complexation with silver ions to suppress its reduction to metallic Ag. As a result, these complexed catalysts show excellent photocatalytic activity for the degradation of methylene blue (MB) dye under the irradiation of visible light. Photocatalytic degradation of MB shows that the catalytic activity is optimized at a condition of 0.5 wt % GN, under which ∼99% of MB was degraded only after 50 min of visible light irradiation. Notably, the complexed catalyst is quite stable and retained almost all of its catalytic activity even after greater than 10 repeated cycles. Moreover, the catalyst can also efficiently decompose 2-chlorophenol, a colorless organic contaminant, under visible light exposure. Detailed experimental investigation reveals that hydroxyl (·OH) radicals play an important role for dye degradation reactions. A relevant mechanism for dye degradation has also been proposed.