基于Cu2O三维纳米结构的高效光解水太阳能电池研究

Development and utilization of new energy is the foundation and strong guarantee for maintaining sustained and rapid increase of China's economy. Solar energy as a clean and renewable energy, is undoubtedly one of the most hot areas of research. This project focuses on fabrication of high efficiency photoelectrochemical cell on the basis of novel three-dimensional branched Cu2O nanostructure. We are planning to use the way of chemical etch to realize control synthesis of Cu2O with the nanostructure of nanowire, nanoflake, nanobelt and three-dimensional branch, breaking through the bottleneck that three-dimensional branched Cu2O nanostructure is hard to be obtained at present. The methods of electrochemical impedance, time-correlated single-photon counting, intensity-modulated photocurrent/photovoltaic spectroscopy will be utilized to analyze working principle of photoelectrochemical cell with Cu2O/ZnFe2O4/C/metal phosphide as photocathode. By discussing effects of p-n junction, protective layer and co-catalysts on the performance of electrodes, factors restricting the efficiency of p-type electrode materials will be obtained and the way for fabrication of high efficiency electrode will be set up. The strategy utilized to synthesize three-dimensional branched Cu2O/ZnFe2O4/C/metal phosphide composite electrode and the idea for assembling photoelectrochemical cell by using composite electrode prepared in this project are pioneering, which will, we believe, provide useful theoretical basis and technical support for the development of new materials and high efficiency photoelectrochemical cells.

新型能源的开发利用是维持我国经济持续快速发展的基础和有力保障。太阳能作为清洁的可再生能源，无疑成为了目前最活跃的研究领域之一。本项目着眼于利用新颖的三维枝状Cu2O纳米结构制备高效的太阳能光解水电池。拟利用化学腐蚀法实现Cu2O纳米线、纳米片、纳米带及三维枝状Cu2O纳米结构的可控合成，突破目前三维枝状Cu2O结构难以合成的技术瓶颈。组装Cu2O/ZnFe2O4/C/金属磷化物复合电极，利用电化学阻抗、时间相关单光子计数、瞬态光电流/电压技术分析电池工作原理，明确p-n结、保护层、催化剂对电极性能的影响，挖掘制约p型电极材料性能的内在因素，建立制备高效复合电极的方法。本项目提出的制备三维枝状Cu2O/ZnFe2O4/C/金属磷化物复合电极的策略及以其组装太阳能光解水电池的设想具有一定的开拓性，有望为新材料的制备和高效太阳能光解水电池的开发提供积极的理论指导和技术支持。

通过深入研究化学腐蚀法反应机制，晶体形成规律及后续晶相转变过程，在透明导电基底上制备了三维枝状氧化铜纳米线。将化学腐蚀法延伸到其它金属前驱体及一维材料的合成当中，实现了由点到面的扩展研究，证明了该方法制备不同一维半导体材料的普适性规律。以磷化氢气相反应为手段，对半导体电极体相和表面实现了原位掺杂和共催化剂修饰，达到了从能带结构/组成调控，界面修饰方面提高光电性能的目的。设计搭建了强度调节光电流测试技术，成功得到了表面电荷传递和复合的动力学数据。有效区分了界面电荷转移行为所包括的转移和复合两种不同过程，克服了常规手段分辨率不足的缺点。本项目提出的合成和改性半导体的方法及测试表征技术具有一定的创新性，对发展高性能催化剂及界面表面态特征的识别和电荷转移动力学定量测量提供了强有力的手段和工具。