Enhanced photocatalytic hydrogen production by introducing the carboxylic acid group into cobaloxime catalysts.
Enhanced photocatalytic hydrogen production by introducing the carboxylic acid group into cobaloxime catalysts.
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DOI：
10.1039/c5dt02645h
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发表时间：
2015-10
影响因子：
4
通讯作者：
Junfei Wang;Chao Li;Qianxiong Zhou;Weibo Wang;Yuan-jun Hou;Bao-wen Zhang;Xuesong Wang
中科院分区：
文献类型：
--
作者：
Junfei Wang;Chao Li;Qianxiong Zhou;Weibo Wang;Yuan-jun Hou;Bao-wen Zhang;Xuesong Wang
一系列钴胺配合物，[Co(iii)(dmgH)2(py-m-X)Cl] (dmgH =二甲基甲氧基肟，py-m-X =元取代吡啶，X = COOH (2), COOCH3 (3), CH2CH2COOH （6), CH2CH2COOCH3(7)）和[Co(iii)(dmgH)2(py-p-X)Cl], (py-p-X =对取代吡啶，X = COOH(4)和COOCH3 (5))，在以杂蒽染料伊红Y为光敏剂（PS）和三乙醇胺（TEOA）为牺牲还原剂（SR）的CH3CN/H2O （1:1, pH = 7.5）人工光合作用体系中，比较了它们的光催化产氢活性。无论是否被供电子基或吸电子基取代，2-7的光催化产氢活性均高于[Co(iii)(dmgH)2(py)Cl](1)。重要的是，在增强光催化活性方面，元取代比对取代更有效，COOH比COOCH3更有效。6的活性最高。连接COOH和吡啶的- ch2ch2 -链可能在6的良好性能中发挥了作用，这使得COOH和dmgH之间通过相互作用实现质子接力成为可能。这项工作为开发更高效的钴肟基析氢催化剂（HERs）开辟了新的途径。
A series of cobaloxime complexes, [Co(iii)(dmgH)2(py-m-X)Cl] (dmgH = dimethylglyoxime, py-m-X = meta-substituted pyridine, X = COOH (2), COOCH3 (3), CH2CH2COOH (6), and CH2CH2COOCH3 (7)), and [Co(iii)(dmgH)2(py-p-X)Cl], (py-p-X = para-substituted pyridine, X = COOH (4) and COOCH3 (5)), were synthesized and their photocatalytic H2 production activities were compared in an artificial photosynthesis system containing a xanthene dye Eosin Y as the photosensitizer (PS) and triethanolamine (TEOA) as the sacrificial reductant (SR) in CH3CN/H2O (1 : 1, pH = 7.5). Irrespective of substitution by an electron-donating or electron withdrawing group, the photocatalytic H2 production activities of 2-7 are all higher than that of [Co(iii)(dmgH)2(py)Cl] (1). Importantly, meta-substitution is more efficient than para-substitution, and COOH is more efficient than COOCH3, in enhancing the photocatalytic activities. 6 showed the highest activity among the examined complexes. The -CH2CH2- chain linking COOH and pyridine might play a role in the promising performance of 6, which makes the proton relay via interaction between COOH and dmgH possible. This work may open new avenues for developing more efficient cobaloxime-based H2 evolution catalysts (HERs).