基于非贵金属二硫化钼/卟啉锌体系的光催化制氢研究

The conversion of solar energy to hydrogen fuel is an opportunity as well as a challenge to solve both energy crisis and environmental pollution. Multicomponent photocatalytic systems for H2 generation typically consist of an organometallic complex as a photosensitizer and inorganic colloid particles as a water reduction catalyst, which has drawn much attention because of it promising potential for robust photocatalytic H2 production. However, most of the efficient photosensitizers and catalysts are both based on noble metal compounds, it is thus important to develop low-cost photosensitizers and catalysts. In this project, photocatalytic hydrogen evolution system is constructed by using zinc porphyrin complexes as photosensitizers and MoS2 nanoparticles as catalyst. The zinc porphyrin complexes have strong light-harvesting ability in visible region, and the carboxyl groups as in zinc porphyrin complexes makes photosensitizers anchor to the MoS2 surface, which enhances the electron transfer from the photosensitizer to MoS2, these factors may make for obtaining high efficient hydrogen production system. This project will involve the following parts: (1) studying of the relationship between structure and photocatalytic properties of MoS2; (2) illuminating of the relationship between structure and photocatalytic properties of porphyrin zinc complexes; (3) revealing of the reaction mechanism of water reduction system and the electron transfer between photosensitizer and catalyst. This project is proposing novel experimental and theoretical basic for develop of noble-metal-free, efficient and stable photocatalytic hydrogen production system that based on MoS2 catalyst and zinc porphyrin photosensitizers.

光催化制氢将太阳能转换为氢能是解决能源危机和环境污染的一个重要机遇和挑战。基于无机纳米粒子胶体催化剂和配合物光敏剂的光催化制氢体系可以快速地将水还原为氢气，但这类体系使用的光敏剂和催化剂通常都是贵金属化合物，开发基于过渡金属的光催化材料对降低体系的成本具有重要的研究意义。本项目在前期研究基础上，构建由二硫化钼催化剂和卟啉锌光敏剂组成的非贵金属光催化制氢体系。由于卟啉锌光敏剂在可见光区域具有强的吸收能力，同时在卟啉锌配合物结构设计上引入羧基，使卟啉锌吸附在二硫化钼纳米粒子表面，加强光敏剂与二硫化钼之间的电荷传输，有利于获得高效的光致产氢体系。本项目主要的研究内容为：(1) 阐明二硫化钼、卟啉锌结构与性能的构效关系；(2) 揭示二硫化钼与卟啉锌之间的电荷传输机制；(3) 探讨该体系产氢的反应机理。项目的成功实施将为构建由过渡金属化合物组成的光催化制氢体系提供实验依据和理论依据。

光催化太阳能制氢技术将太阳能转换为氢能是解决当前能源危机和环境污染的一个重要机遇和挑战。然而，目前光催化制氢体系主要使用贵金属化合物为催化剂材料，开发基于低成本的过渡金属的光催化材料对降低体系的成本具有重要的研究意义。本项目构建了以MoS2为催化剂、卟啉锌配合物为光敏剂的高效光催化制氢体系，研究了它们结构与光催化性能的构效关系；通过荧光光谱仪，光电流和荧光衰减等表征手段研究了MoS2催化剂与卟啉锌光敏剂之间的电荷传输机制，探讨光催化制氢体系的反应机理。我们的研究结果表明在卟啉锌光敏剂和MoS2催化剂之间引入石墨烯，ZnO等载流子传输材料可以有效地加速卟啉锌光生电子向MoS2的传输，增强了体系的光催化制氢性能。本项目优化的基于卟啉锌和MoS2的光催化制氢体系在420 nm单色光下的表观量子效率达到了15.2%。此外，我们还拓展了MoS2基的光催化体系，使用无机半导体染料为光敏剂，构建了无机半导体染料与MoS2的光催化体系。本项目的成功实施具有重要的研究意义和应用前景，为构建基于过渡金属化合物的高效、稳定、环境友好、低成本的太阳能制氢体系提供重要的借鉴和参考价值。