Towards a comprehensive insight into efficient hydrogen production by self-assembled Ru(bpy)(3)(2+)-polymer-Pt artificial photosystems
Towards a comprehensive insight into efficient hydrogen production by self-assembled Ru(bpy)(3)(2+)-polymer-Pt artificial photosystems
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通过自组装Ru(bpy)(3)(2)-聚合物-Pt人工光系统全面了解高效产氢
DOI：
10.1039/c5cp00720h
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发表时间：
2015
影响因子：
3.3
通讯作者：
Wang Xuxu
中科院分区：
文献类型：
--
作者：
Lin Huan;Liu Dan;Long Jinlin;Zhang Zizhong;Zhuang Huaqiang;Zheng Yi;Wang Xuxu
聚合物在人工光系统中的作用已被详细研究。该光系统由三（2，2 ′-联吡啶）氯化钌（II）作为光敏剂（PS）、聚合物稳定的胶体Pt作为放氢催化剂和抗坏血酸钠作为电子给体组成，不添加传统的分子电子介体。实现了对可见光照射下氢气生产的全面了解。几种聚合物，包括中性聚乙烯吡咯烷酮，阴离子聚（4-苯乙烯磺酸钠）和聚（丙烯酸）不仅稳定的纳米粒子，但也有效地在生产氢气。在最佳条件下，获得了12.8%的析氢表观量子效率。通过PS和聚合物-Pt之间的非共价分子间相互作用形成的自组装和空间分离的供体-受体复合物是太阳能高效转化为氢燃料的关键。利用纳秒瞬态吸收光谱和时间分辨荧光光谱研究了自组装人工光系统中光诱导电子和能量传递过程的重要细节。光催化制氢的初始步骤是通过抗坏血酸钠还原猝灭PS的三重激发态，得到还原形式的PS，然后其可以被聚合物快速猝灭。速率控制步骤是电子通过聚合物桥从PS转移到催化剂。
The role of polymers in artificial photosystems has been studied in detail. The photosystems were composed of tris(2,2′-bipyridyl) ruthenium(II) chloride as a photosensitizer (PS), colloidal Pt stabilized by polymer as a hydrogen-evolving catalyst and sodium ascorbate as an electron donor, without the addition of a traditional molecular electron mediator. Comprehensive insights into the production of hydrogen on irradiation with visible light were achieved. Several polymers, including neutral polyvinyl pyrrolidone, anionic poly(sodium 4-styrene sulfonate) and poly(acrylic acid) not only stabilized the nanoparticles, but were also effective in the production of hydrogen. Under the optimum conditions, an outstanding apparent quantum efficiency of 12.8% for the evolution of hydrogen was achieved. The formation of self-assembled and spatially separated donor–acceptor complexes via the non-covalent intermolecular interaction between PS and the polymer–Pt was pivotal in the efficient conversion of solar energy to hydrogen fuel. Important details of the photo-induced electron and energy transfer processes in the self-assembled artificial photosystems were determined by nanosecond transient absorption spectrometry and time-resolved fluorescence spectrometry. The initial step in the photo-catalytic production of hydrogen was a reductive quenching of the triplet excited state of the PS by sodium ascorbate, leading to a reduced form of PS, which could then be quickly quenched by the polymer. The rate-determining step was the electron transfer from PS to the catalyst via the polymer bridge.