HYDROGEN GENERATION BY VISIBLE-LIGHT IRRADIATION OF AQUEOUS-SOLUTIONS OF METAL-COMPLEXES - APPROACH TO THE PHOTO-CHEMICAL CONVERSION AND STORAGE OF SOLAR-ENERGY
HYDROGEN GENERATION BY VISIBLE-LIGHT IRRADIATION OF AQUEOUS-SOLUTIONS OF METAL-COMPLEXES - APPROACH TO THE PHOTO-CHEMICAL CONVERSION AND STORAGE OF SOLAR-ENERGY
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DOI：
10.1002/hlca.19790620449
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发表时间：
1979-01-01
影响因子：
1.8
通讯作者：
SAUVAGE, JP
中科院分区：
文献类型：
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作者：
KIRCH, M;LEHN, JM;SAUVAGE, JP
本文描述了一种在可见光或太阳光照射下，水溶液还原产生氢的光化学体系，该体系包括：光敏剂Ru（bipy）配合物，用于可见光吸收，中继物种Rh（bipy）配合物，通过还原态中间储存电子介导水还原;电子供体三乙醇胺（TEOA），其为还原过程提供电子;以及氧化还原催化剂胶体铂，其促进氢的形成。研究了高效产氢的条件和组分浓度的影响;金属配合物作为催化剂具有高的转化数;过量的联吡啶有利于反应。该过程包括两个催化循环：钌循环和铑循环。Ru循环涉及Rh（bipy）对 *Ru（bipy）激发态的氧化淬灭，形成Ru（bipy），其通过电子供体TEOA的氧化转化回Ru（bipy），从而消耗。Rh循环包括初始Rh（bipy）络合物的一组复杂的转变。在淬灭过程中形成的还原铑络合物经历了一系列涉及Rh（bipy）络合物和铑-联吡啶物质的转化，通过与水的质子反应产生氢气。考虑到在还原的铑物种中储存了两个电子，该过程在形式上是非电子水还原。研究了[Rh（III）（bipy）2LL′]n+（L，L′ = H2O，OH−）物种的性质和最终参与.它的结论是，在中性pH值在过量的联吡啶的存在下，涉及Rh（bipy）配合物的再生的循环是占主导地位的。已经用改进的系统进行了许多实验。在其他光敏剂（如原黄素）、其他中继物质（如Rh（二甲基联吡啶）或Co（II）-联吡啶络合物）、其他供体物质或不存在铂催化剂的情况下观察到析氢。它也发生在没有光敏剂的情况下，由紫外线的阳光。通过Rh（bipy）照射或通过铱（III）-联吡啶络合物的可见光照射来制备。这些系统值得进一步研究。本发明的光化学制氢系统代表了完整的水裂解过程的还原组分。它在太阳能转换和光化学燃料生产中的作用进行了讨论。
We describe a photochemical system for the generation of hydrogen by water reduction under visible light or sunlight irradiation of aqueous solutions containing the following components: a photosensitizer, the Ru (bipy) complex, for visible light absorption; a relay species, the Rh (bipy) complex, which mediates water reduction by intermediate storage of electronsviaa reduced state; an electron donor, triethanolamine (TEOA) which provides the electrons for the reduction process and a redox catalyst, colloïdal platinum, which facilitates hydrogen formation. The conditions for efficient hydrogen production and the influence of the concentration of the components have been investigated; the metal complexes act ascatalystswith high turnover numbers; excess bipyridine facilitates the reaction. The process contains two catalytic cycles: aruthenium cycleand arhodium cycle. The Ru cycle involves oxidative quenching of the *Ru(bipy) excited state by Rh(bipy) forming Ru(bipy) which is converted back to Ru(bipy) by oxidation of the electron donor TEOA, which is thus consumed. The Rh cycle comprises a complicated set of transformations of the initial Rh(bipy) complex. The reduced rhodium complex formed in the quenching process undergoes a series of transformations involving the Rh(bipy) complex and hydridorhodium‐bipyridine species, from which hydrogen is generated by reaction with the protons of water. In view of the storage of two electrons in the reduced rhodium species, the process is formally adielectronic water reduction. The properties and eventual participation of [Rh(III)(bipy)2LL′]n+(L,L′ = H2O, OH−) species are investigated. It is concluded that at neutral pH in presence of excess bipyridine, the cycle involving regeneration of the Rh(bipy) complex is predominant. A number of experiments have been performed with modified systems. Hydrogen evolution is observed with other photosensitizers (like proflavin), other relay species (like Rh(dimethylbipy) or Co(II)‐bipyridine complexes), other donor species, orin absenceof the platinum catalyst. It also occurs in absence of photosensitizer by sunlight of UV. irradiation of Rh(bipy) or by visible light irradiation of iridium (III)‐bibyridine complexes. These systems deserve further investigations. The present photochemical hydrogen generating system represents the reductive component of a complete water splitting process. Its role in solar energy conversion and in photochemical fuel production is discussed.