缺陷态石墨烯负载CdS复合材料结构与分解水制氢性能的第一性原理研究

Two biggest problems for the modern human beings are the energy crisis and environmental pollution. The research indicates that graphene as a substrate could improve the photoelectrochemical activity of semiconductor materials under the visible light significantly. However, The mechanism of the high photoelectrochemical activity of semiconductor catalysts caused by graphene is still under debate. Inheritting from experience of computing simulation and employing the Molecular Dynamics (MD) and density functional theory (DFT) from the first principles, we are going to investigate the surface and interface effects between graphene and CdS semiconductor caused by the defect states in graphene. We analyze the structural stability and electronic properties between the two. It allows us to reveal the nature of the interaction between π electrons from carbon materials with the outer most electrons from CdS clusters. Additionally, the caltalytic activity of CdS/Graphene will be investigated by using the H2O reduction as a benchmark probe. By this way, it will open a new avenue to establish low cost and highly efficient catalytic system theoretically.

能源危机和环境污染是现代人类面临的两大难题。实验研究发现石墨烯作为载体能够显著改进半导体材料可见光下的光电化学活性，然而对其物理机制尚不清楚。该项目采用第一性原理的密度泛函理论和分子动力学方法，研究缺陷态石墨烯负载半导体催化剂CdS复合材料的结构与分解水制氢性能关系；分析石墨烯片层数与CdS团簇尺寸对复合材料结构稳定性的影响，揭示碳材料中π电子与CdS外层电子间的相互作用规律；通过优化复合材料结构，模拟其表面催化还原H2O生成H2的反应过程。从而揭示CdS-石墨烯复合材料高效催化机理,为开发新型高效催化材料奠定理论基础。

运用第一性原理方法研究缺陷态石墨烯负载半导体催化剂复合材料结构与性能，揭示催化反应机理，为新型高效催化剂的合成提供理论依据。在研究过程中，基本遵循原计划的研究方案、技术路线和研究计划，模拟研究石墨烯负载半导体材料的纳米复合结构，阐明半导体材料，以及在各种缺陷杂质存在下石墨烯衬底上的稳定吸附规律；深入分析了复合催化材料电子结构，模拟不同尺寸CdS团簇间相互作用的电子结构特征以及高效催化活性机理；以H2O还原反应为测试平台，搭建纳米缺陷态结构CdS表面和CdS/Graphene复合材料催化反应理论模型，研究室温下不同CdS表面和复合材料催化分解H2O产生氢气的反应机理，该研究为项目难点，仍需进一步深入细致研究。研究过程中同时也遇到了一系列的实际问题，比如：衬底各种缺陷以及杂质的存在对半导体催化剂CdS的吸附性能、电子结构等有着不同的影响，对此尝试类比研究了杂质缺陷对Bi2O3、TiO2等半导体催化剂催化性能的影响，以及碱式碳酸铜在加压情况下材料的电磁特性。在项目执行期间，发表SCI论文3篇，提交受理发明专利一项，近期接收一篇SCI论文，部分相关结果仍需细致分析，将另有两篇SCI论文待投，基本上完成了项目预期的研究目标。