Efficient photocatalytic dechlorination of chlorophenols over a nonlinear optical material Na3VO2B6O11 under UV-visible light irradiation
Efficient photocatalytic dechlorination of chlorophenols over a nonlinear optical material Na3VO2B6O11 under UV-visible light irradiation
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非线性光学材料Na3VO2B6O11在紫外-可见光照射下高效光催化脱氯氯酚
DOI：
10.1039/c5ta01814e
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发表时间：
2015-01-01
影响因子：
11.9
通讯作者：
Wang, Chuanyi
中科院分区：
文献类型：
--
作者：
Fan, Xiaoyun;Lai, Kangrong;Wang, Chuanyi
合成了一种具有非中心对称性的非线性光学晶体Na 3VO 2B 6 O 11（NVB），并在紫外可见光（λ> 320 nm）照射下对2，4-DCP的脱氯反应显示出优异的光催化活性。在相同条件下，该催化剂的脱氯效率比商业P25 TiO 2催化剂高90倍。NVB的非中心对称结构引起了一个内在的大极化效应证明了开尔文探针力显微镜，和极化促进光生电子-空穴对的分离，导致有效的裂解氯酚酚系列片段和解离的Cl-阴离子。提出了紫外可见光照射下NVB对2，4-DCP脱氯的可能反应途径。发现2，4-DCP脱氯的主要反应途径是加氢脱氯，与羟基自由基反应生成1，4-苯醌和邻苯二酚。本工作进一步加深了对非线性光学材料的理解，为利用非线性光学材料设计和合成高效光催化剂开辟了一条新的途径。
One type of nonlinear optical crystal Na3VO2B6O11 (NVB) with noncentrosymmetry was synthesized and shows extraordinary UV-visible light driven photocatalytic activity in the dechlorination of 2,4-DCP under UV-vis (lambda > 320 nm) light irradiation. The obtained dechlorination efficiency is 90 times higher than that of the commercial P25 TiO2 catalyst under the same conditions. The noncentrosymmetric structure of NVB gives rise to an intrinsic large polarization effect as evidenced by Kelvin probe force microscopy, and the polarization promotes separation of photogenerated electron-hole pairs, leading to efficient cleavage of chlorophenols into phenol series fragments and dissociative Cl- anions. A possible reaction pathway for 2,4-DCP dechlorination by NVB upon UV-vis light irradiation is proposed. Hydrodechlorination was found to be the major reaction pathway for 2,4-DCP dechlorination which could react with hydroxyl radicals to produce 1,4-benzoquinone and ocatechol. This work further advances the understanding of nonlinear optical materials, which opens up a new route to the design and synthesis of highly efficient photocatalysts by using nonlinear optical materials.