Dye-sensitized photoanode decorated with pyridine additives for efficient solar water oxidation  

修饰吡啶衍生物的染料敏化光阳极水氧化性能的研究

作　　者：Jiayuan Li Yong Zhu Fei Li Guoquan Liu Suxian Xu Licheng Sun 李佳原;朱勇;李斐;刘国权;许素显;孙立成(大连理工大学精细化工国家重点实验室,大连理工大学-瑞典皇家工学院分子器件联合中心,中国辽宁大连116024;瑞典皇家工学院化学系,瑞典斯德哥尔摩;西湖大学理学院,人工光合作用与太阳能燃料中心,中国浙江杭州310024)

机构地区：[1]State Key Laboratory of Fine Chemicals,DUT-KTH Joint Education and Research Center on Molecular Devices,Dalian University of Technology(DUT),Dalian 116024,Liaoning,China [2]Department of Chemistry,School of Engineering Sciences in Chemistry,Biotechnology and Health,KTH Royal Institute of Technology,Stockholm 10044,Sweden [3]Center of Artificial Photosynthesis for Solar Fuels,School of Science,Westlake University,Hangzhou 310024,Zhejiang,China

出　　处：《Chinese Journal of Catalysis》2021年第8期1352-1359,共8页催化学报（英文）

基　　金：国家自然科学基金(21872016);辽宁省兴辽英才计划(XLYC1807125);瑞典能源部.

摘　　要：Splitting water into hydrogen and oxygen by dye-sensitized photoelectrochemical cell(DSPEC)is a promising approach to solar fuels production.In this study,a series of pyridine derivatives as surface additives were modified on a molecular chromophore and water oxidation catalyst co-loaded TiO_(2)photoanode,TiO_(2)|RuP,1(RuP=Ru(4,4′-(PO3H2)2-2,2′-bipyridine)(2,2′-bipyridine)2,1=Ru(bda)(L)2,(bda=2,2′-bipyridine-6,6′-dicarboxylate,L=10-(pyridin-4-yloxy)decyl)phosphonic acid).The addition of pyridine additives was found to result in up to 42%increase in photocurrent.Under simulated sun-light irradiation,TiO_(2)|RuP,1,P1(P1=4-Hydroxypyridine)produced a photocurrent density of 1 mA/cm2 at a bias of 0.4 V vs.NHE in acetate buffer.Moreover,the observed photocurrents are correlated with the electron-donating ability of the substituent groups on pyridine ring.Transient absorption measurements and electrochemical impedance spectroscopy revealed that surface-bound pyridine can effectively retard the back-electron transfer from the TiO_(2)conduction band to the oxidized dye,which is a major process responsible for energy loss in DSPECs.染料敏化光电化学电池(DSPECs)是构建人工光合作用体系的潜在方式,其优势在于可通过优化染料结构来拓展可见光吸收范围,从根本上提高太阳能利用效率.染料敏化光阳极在受激发产生电荷分离之后,激发电子注入TiO_(2)半导体导带,由于其导带位置比传统的可见光半导体,如BiVO4和Fe3O4等相比较负,因此理论上可以在较小的偏压下取得较大的光电转换效率,也更有利于和光阴极相耦合实现无偏压分解水.电荷传输动力学研究表明,注入到TiO_(2)导带的电子向氧化态光敏剂和催化剂的回传是造成体系能量损失的主要原因,集中体现在光电流密度和效率的降低.目前,已经报道了多种手段来减少DSPECs光阳极表面的电子回传,包括使用带有长烷基链的锚定基团对水氧化催化剂进行修饰,在半导体表面引入电子中介体以及使用核-壳结构的基底等.其中,SnO2/TiO_(2)基底被广泛应用在染料敏化光阳极中,这种基底可以提高光生电子的注入效率,同时两种金属氧化物之间的异质结有效抑制了电子回传,从而提高了DSPECs的光电活性.然而,核-壳结构基底需要使用原子层沉积技术来制备,所以操作相对复杂.本文基于Ru-bda(bda=2,2'-联吡啶-6,6'-二羧酸)结构的分子水氧化催化剂和带有磷酸修饰基团的三联吡啶钌通过共吸附的方式制备染料敏化光阳极,在不使用核-壳结构基底的情况下,利用吡啶衍生物对TiO_(2)电极表面的修饰来减少电子回传.本文利用一系列吡啶衍生物作修饰负载在TiO_(2)光阳极上(TiO_(2)|RuP,1;RuP=Ru(4,4'-(PO3H2)2-2,2'-联吡啶)(2,2'-联吡啶)2;1=Ru(bda)(L)2,bda=2,2'-联吡啶-6,6'-二羧酸,L=(10-吡啶-4-基氧基)癸基)膦酸.在100 mW/cm2的白光照射下(λ>400 nm),TiO_(2)|RuP,1,P1(P1=4-羟基吡啶)光阳极在0.4 V(vs.NHE)的外加偏压下获得了1 mA/cm2的光电流密度,其光电流比未修饰吡啶的光阳极增加了42%.同时,其入射光子-电�

关 键 词：DYE-SENSITIZED photoelectrochemical cell Water splitting PHOTOANODE Surface modification Pyridine derivatives 

分 类 号：TM91[电气工程—电力电子与电力传动] TQ610.1[化学工程—精细化工]