石墨烯复合结构的太阳能光伏电解水制氢性能研究

发布时间：2019-05-28 12:58

【摘要】：开发利用清洁可再生能源,是解决能源与环境问题的有效途径。太阳能是重要的可再生能源,太阳能光伏电解水制氢系统可实现其高效充分的利用,太阳电池单元将光能转换为电能,直接使用;富余电能驱动电解水制氢单元,使电能转换为氢能存储利用。基于石墨烯的新型纳米材料具有优异的光学、电学及力学等性能,合理利用有望进一步提升该技术中的光电转换效率,降低电解水制氢的能耗与成本。本论文以开发太阳能光伏电解水制氢系统为目标,首先,将石墨烯与固态电解质复合,优化石墨烯/硅太阳电池模型结构,实现了光能至电能的高效转换。其次,将石墨烯与过渡族金属化合物复合,降低了电解水制氢中贵金属的使用量,并实现了电能至氢能高效且稳定的转换。将太阳电池与电解水单元串联,构建光伏电解水制氢系统,最终实现了太阳能的直接利用与转换利用。为了开发系统中的太阳电池单元,从优化石墨烯/硅太阳电池的模型结构出发,组装网状石墨烯/硅-固态电解质太阳电池,研究并探讨了固态电解质在其中的多重工作机制。该器件中异质结与光电化学通道协同作用,共同提升转换效率至11%,保证了光能至电能的高效转换与利用。为了降低电解水过程中催化剂铂的使用量,将石墨烯与过渡族金属硫化物复合,制备了石墨烯/二硫化钼层片复合结构。研究了该结构在酸性电解质中的制氢性能。为进一步提升催化活性,在其上沉积少量铂纳米粒子,并对光诱导铂负载的机制进行了探讨与分析。在石墨烯/二硫化钼-铂纳米粒子催化剂中,二硫化钼可以部分替代铂,制氢过电势低至56 m V,作为电解水单元的阴极催化剂,实现了电能至氢能的高效转换。为了合成非贵金属全分解水催化剂,将石墨烯与过渡族金属硒化物复合。通过形貌调控,合成石墨烯-硒化钴/镍垂直纳米层片复合结构,其在碱性电解质中具有优异的制氢及制氧双功能,可同时作为电解水单元阴极及阳极催化剂,取代了贵金属铂。与网状石墨烯/硅-固态电解质太阳电池串联,搭建了光伏电解水制氢系统,实现了电能至氢能高效且稳定的转换。
[Abstract]:The development and utilization of clean and renewable energy is an effective way to solve the problems of energy and environment. Solar energy is an important renewable energy. Solar photovoltaic electrolytic water hydrogen production system can make full use of it efficiently and fully. Solar cell unit converts light energy into electric energy and uses it directly. The surplus electric energy drives the hydrogen production unit of electrolytic water, which converts the electric energy into hydrogen energy storage and utilization. The new graphene based nanomaterials have excellent optical, electrical and mechanical properties. Reasonable utilization is expected to further improve the photoelectric conversion efficiency of this technology and reduce the energy consumption and cost of hydrogen production from electrolytic water. In this paper, the hydrogen production system of solar photovoltaic electrolytic water is developed. Firstly, graphene and solid electrolyte are combined to optimize the model structure of graphene / silicon solar cell, and the efficient conversion from light energy to electric energy is realized. Secondly, graphene is combined with transition metal compounds to reduce the use of precious metals in hydrogen production from electrolytic water, and the efficient and stable conversion from electric energy to hydrogen energy is realized. The solar cell is connected with the electrolytic water unit to construct the photovoltaic electrolytic water hydrogen production system, and finally the direct utilization and conversion and utilization of solar energy are realized. In order to develop the solar cell unit in the system, the reticulated graphene / silicon-solid electrolyte solar cell was assembled from optimizing the model structure of graphene / silicon solar cell, and the multiple working mechanism of solid electrolyte in it was studied and discussed. In this device, the Heterojunction and photochemical channel work together to improve the conversion efficiency to 11%, which ensures the efficient conversion and utilization of light energy to electric energy. In order to reduce the amount of platinum used as catalyst in electrolytic water, graphene / Mo disulfide lamellar composite structure was prepared by combining graphene with transition metal sulfides. The hydrogen production performance of the structure in acidic electrolytes was studied. In order to further improve the catalytic activity, a small amount of platinum nanoparticles were deposited on it, and the mechanism of photoinduced platinum loading was discussed and analyzed. In graphene / molybdenum disulfide platinum nanoparticles catalyst, Mo disulfide can partly replace platinum and the overpotential of hydrogen production is as low as 56 MV. As the cathode catalyst of electrolytic water unit, the high efficiency conversion from electric energy to hydrogen energy can be realized. In order to synthesize non-precious metal fully decomposed water catalyst, graphene was combined with transition metal selenide. Graphene-cobalt selenide / nickel vertical nanolamellar composite structure was synthesized by morphology control. It has excellent functions of hydrogen production and oxygen production in alkaline electrolytes, and can be used as cathode and anode catalyst of electrolytic water at the same time. Replaced precious metal platinum. In series with reticulated graphene / silicon-solid electrolyte solar cell, a photovoltaic electrolytic water hydrogen production system was built to realize the efficient and stable conversion from electric energy to hydrogen energy.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ116.2;O643.36

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