Development of catalysts, namely manganese oxides and molybdenum sulphides, for an implementation in a light-driven water-splitting device using a multi-junction solar cell

该项目的目标是无贵金属催化剂，适用于光驱动装置，用于从水中生产氢气，作为“太阳能燃料”。设想的装置包括：a）用于水氧化催化的无定形Mn氧化物，B）用于质子还原催化的Mo硫化物，和c）用于光诱导产生电势差的多结半导体系统。结构和功能的调查将促进知识引导的催化剂，这是金属酶的功能模拟物和高的兴趣也为就业在其他水裂解系统的优化。我们的目标是生物启发的，因此不含贵金属的催化剂，这可以促进大规模应用，而不受原材料稀缺的阻碍。阳极和阴极催化剂分别进行了研究，结合电化学和光谱。用X射线吸收光谱（XAS）研究了大部分非晶态催化剂的原子结构和氧化态。作为原理证明，将组装和研究一个完整的混合电池。我们在第一个资助期的主要重点是对沉积在惰性电极上的Mn基OER（析氧反应）和MoSx基HER（析氢反应）电催化剂的结构-活性关系的基本见解。在第二个资助期内，我们计划继续使用现在建立的（i）催化剂合成，（ii）功能表征，（iii）原子结构研究和（iv）光伏测试系统中的催化剂操作的组合。我们将继续采取一种研究策略，旨在获得基本的见解，而不仅仅是经验性的催化剂和设备优化，但将把重点转移到匹配催化剂材料的要求与太阳能电池的要求。我们在第二个资助期的主要目标是：（1）对Mn基OER和MoSx基HER催化剂进行知识指导的催化剂改性，以改善与辐照多结太阳能电池的电流-电压特性的兼容性;（2）改进稳定固定方法，- 将电催化剂（沉积）在太阳能电池组件的接触层上;（3）深入了解有效OER和HER电催化的电解质要求，重点关注pH制度、质子接受离子和与光伏系统的兼容性的作用;（4）用于光驱动的H2形成的测试系统的操作，所述测试系统包括三结PV电池和基于锰和钼的地球上丰富的催化剂材料。

This project aims at precious-metal-free catalysts suitable for implementation in a light-driven device for producing H2, as a 'solar fuel', from water. The envisioned device comprises: a) amorphous Mn oxides for water oxidation catalysis, b) Mo sulphides for catalysis of proton reduction, and c) a multi-junction semiconductor system for light-induced generation of an electrical potential difference. Structural and functional investigations will facilitate a knowledge-guided optimisation of the catalysts, which are functional mimics of metalloenzymes and of high interest also for employment in other water-splitting systems. We are aiming at bio-inspired and thus precious-metal-free catalysts, which could facilitate large-scale application unhindered by raw-material scarcity. The anodic and cathodic catalysts are investigated separately by combining electrochemistry with spectroscopy. Atomic structures and oxidation states of the mostly amorphous catalysts are investigated X-ray absorption spectroscopy (XAS). As a proof-of-principle, a complete hybrid cell will be assembled and studied. Our main focus of the first funding period has been basic insights in structure-activity relations of Mn-based OER (oxygen evolution reaction) and MoSx-based HER (hydrogen evolution reaction) electrocatalysts deposited on inert electrodes. In the second funding period, we plan to go ahead using the now established combination of (i) catalyst synthesis, (ii) functional characterisation, (iii) investigation of the atomic structure, and (iv) catalyst operation in a photovoltaic test system. We will continue with a research strategy that aims at basic insights rather than merely empirical catalyst and device optimisation, but will shift focus towards matching the requirements of the catalyst materials with those of the solar-cell. Our central objectives for the second funding period are: (1) knowledge-guided catalyst modification of Mn-based OER and MoSx-based HER catalysts for improved compatibility with the current-voltage properties of an irradiated multi-junction solar cell; (2) improved methods for the stable immobilisation (deposition) of the electrocatalysts on the contact layers of the solar cell assembly; (3) insights into the electrolyte requirements for efficient OER and HER electrocatalysis with focus on the role of pH regime, proton-accepting ions, and compatibility with the photovoltaic system; (4) operation of test systems for light-driven H2-formation comprising triple-junction PV cells and earth-abundant catalyst materials based on manganese and molybdenum.