三维1T相MoS2/g-CN/石墨烯气凝胶独立光阳极的制备及其光电催化机理研究

Photoelectrocatalytic water splitting is an ideal method for the evolution of hydrogen, one of the world’s most important clean energy. The development of effective photoanode is the most essential yet challenging part in this research field. Graphitic carbon nitride (g-CN) is a relative novel non-metal semiconductor, which is low-cost and easily-obtainable. However, photoanodes based on g-CN usually showed low efficiency for the poor conductivity and high recombination rate of photo-excited charge carriers on g-CN. Tightly combining 2D g-CN with 2D graphene could enhance the conductivity of g-CN and the separation and transfer of electrons. Besides, MoS2 with 1T phase has been very popular recently for its special properties and has shown promoting effect for photoanodes. But the underlying mechanism has not been elucidated. Therefore, in this project, we planned to fabricate a new 3D 1T-MoS2/g-CN/graphene aerogel through a simple and green hydrothermal rought. The sample will be optimized by adjusting the synthesis conditions including the content of precursors, time, temperature, microwave intensity, etc. Subsequently, the photoelectrocatalytic mechanism, especially the role of 1T-MoS2 would be studied and discussed with the characterization results, Quantum chemical calculation and additional control experiments. The fulfilment of this project is expected to provide valid experimental and theoretical support for the further development of novel low-cost and advanced photoanode for high-efficiency photoelectrocatalytic water splitting.

光电解水是开发清洁能源氢气的理想途径之一，高效光阳极的开发是该领域的研究重点与难点。类石墨相氮化碳（g-CN）是较新型的非金属半导体材料，其经济易得，但于由于其导电性差、光生电荷分离效率低，g-CN基光阳极效率普遍较低；将二维的g-CN与二维的石墨烯紧密结合，将有效增强g-CN的电子传输性能，降低其光生电子和空穴的复合率；1T金属相MoS2性能特殊，近年来受到广泛研究关注，最近研究发现其亦能够促进光阳极材料光电催化性能，但相关的作用机理尚不明晰。本项目计划通过绿色便捷的水热法制备新型的三维1T相MoS2/g-CN/石墨烯气凝胶独立电极，通过调控前驱体、时间、温度、微波强度等水热合成条件，优化样品性能，并结合材料表征分析、对照试验、量子化学理论计算等手段，深入研究所得样品的光电催化机理，尤其是1T相MoS2在其中的作用，以期为新型的经济高效的光阳极材料的开发提供有效的实验与理论支持。

氢气是重要的清洁能源，通过光或电等绿色手段分解水是清洁制氢有效途径，而开发高效、实用的电极材料对实现电/光电解水制氢技术的广泛应用尤为关键。1T金属相硫化钼（MoS2）等廉价过渡金属硫属化合物，因其较突出的电化学性能，近年来受到广泛的研究关注，被认为有望替代当前贵金属Pt等材料用于高效电解水产氢。但是，当前开发的过渡金属硫属化合物电极材料多为粉体，需在经过加工成型才有可能投入到实际应用，而在此过程中，难以避免性能的损失，且后续面临着电极稳定性的问题。针对上述问题，本项目选定机械性能稳定、表面富含狭缝结构、且未受研究关注的石墨棒为三维基底，开发了一系列过渡金属硫属化合物独立三维电极，不仅优化了合成工艺，并对所得三维电极进行深入的构效分析，且为确保电极稳定性提出了针对性方案。本研究将为三维独立电极开发提供有效的新思路，并为廉价高效电解水电极的实现提供有力的理论与技术支撑。