极性半导体的表面改性及其光催化降解空气中甲烷的性能与机理研究

The approach on how to reduce the photon energy required for the activation of methane in the adsorption state by the interaction of methane molecules with special photocatalysts, and achieve high-efficiency photocatalytic activation of C-H bonds in methane, is a key scientific issue in the development of methane photocatalytic conversion and oxidation research. In this project, we propose to conduct a study to make use of polar semiconductors with good optoelectronic properties as raw photocatalysts, by means of surface regulation to realize the synergistic effect of built-in electric field, surface plasmon resonance, adsorption site and active site on catalytic activation of C-H bond in methane. Simultaneously, the anomalous photovoltaic effect of polar semiconductors provides strong redox capability for photocatalytic oxidation of methane will be explored. Accordingly, we could comprehensively investigate the performance and mechanism of photocatalytic degradation of methane in air by polar semiconductors. To begin with, the polar semiconductors will be synthesized by suitable methods and their surface will be modified by some surface treatment techniques. Then, after finishing the characterization and photocatalytic activity tests of photocatalysts, the underlying mechanism will be unraveled with the aid of in-situ spectroscopic characterizations and theoretical modeling. Finally, high efficient photocatalytic materials with broad solar spectrum response will be prepared by optimizing the synthetic approach. Projects from this proposed research will be very useful for the environmental remediation of atmospheric hydrocarbons, photocatalytic conversion and oxidation of methane, and photocatalytic reduction of CO2 to methane.

如何通过甲烷分子与特殊光催化剂的相互作用，降低吸附态甲烷活化所需光子能量，实现甲烷C―H键的高效光催化活化，是推进甲烷光催化转化及氧化研究领域发展的关键科学问题。本项目拟在引入具有良好光电性能的极性半导体的基础上，通过其表面改性，实现内建电场、表面等离子共振、吸附位点、活性位点对光催化活化甲烷C―H键的协同增效，同时利用极性半导体的反常光伏效应为光催化氧化甲烷提供强氧化还原能力，从而开展极性半导体光催化降解空气中甲烷的性能与机理研究。首先，采用合适的材料制备方法及表面改性技术实现极性半导体的可控制备及其表面调控；然后，在进行结构表征和光催化性能测试的基础上，借助原位谱学表征和理论计算模拟开展机理研究；最后，通过优化反应体系和工艺参数获得高效宽广光谱响应的光催化材料，为空气中碳氢污染物的治理、甲烷的光催化转化及氧化、光催化还原CO2制甲烷提供理论支持与借鉴。

如何通过甲烷分子与特殊光催化剂的相互作用，降低吸附态甲烷活化所需光子能量，实现甲烷C―H键的高效光催化活化，是推进甲烷光催化转化及氧化研究领域发展的关键科学问题。本项目在具有良好光电性能的极性半导体的基础上，通过其表面改性，实现内建电场、表面等离子共振、吸附位点、活性位点对光催化活化甲烷C―H键的协同增效，同时利用极性半导体的反常光伏效应为光催化氧化甲烷提供强氧化还原能力，从而开展了极性半导体光催化降解空气中甲烷的性能与机理研究，实现了利用太阳光高效光催化降解空气中的甲烷，为空气中碳氢污染物的治理、甲烷的光催化转化及氧化、光催化还原CO2制甲烷提供理论支持与借鉴。.目前通过各种材料合成方法制备了一系列极性半导体，如：Bi2WO6、Bi2MoO6、CdS、ZnS、ZnIn2S4、ZnO等，并通过光催化降解甲烷性能测试发现极性最强的ZnO具有最佳的光催化性能，证实了利用极性半导体内建电场来活化甲烷中C-H键是一种有效的途径。在此基础上，我们利用单原子负载、表面氧空位调控、自旋极化调控等手段进一步提升了ZnO光催化降解甲烷的性能，并探索了甲烷中C-H键活化的机制以及提升光催化材料催化活性、稳定的方法。本项目经过三年的执行期，发表了7篇高水平SCI论文，其中包括Chemical Engineering Journal、Journal of Hazardous Materials、Separation and Purification Technology等具有国际影响力期刊，3篇中文期刊，申请9件发明专利，授权5件，指导学生荣获第十五届全国三维数字化创新设计大赛湖北省赛区特等奖、全国总决赛三等奖，培养毕业硕士生4人、博士1人、本科毕业生12人。