氮化物、氧氮化物光阳极性能改善及其稳定性提高

An ideal strategy to conversion and storage of solar energy is photocatalytic water splitting into hydrogen or reducing CO2 into carbon-containing fuels, which exhibits the potential applications in solving energy and environment problems. Water oxidation reaction is the most important half-reaction process for water splitting and CO2 reduction. To achieve the efficient water oxidation reaction, this project was proposed to construct the efficient Ta3N5, LaTiO2N and LaTaON2 photoanodes, which can achieve the theoretical solar-to-hydrogen efficiency of 16% and have the ability in water splitting without applied bias. Here, we will focus on the following research contents: (1)Exploring the preparation methods of high-quality films of nitrides and oxynitrides ; (2) Finding the fabrication routes of Ti-based protective layer and its function in stability improvement of nitrides and oxynitrides photoabsorbing layer; and (3) Developing the low-cost Co, Fe or Ni based bulk electrocatalytic materials with low crystallinity for improving the photocatalytic performance of nitrides and oxynitrides. It is expected that the research results can be the experimental basis and scientific guide for the applications of nitrides and oxynitrides photocatalysts in water splitting and CO2 reduction.

光催化分解水制氢或还原CO2为碳基燃料是一步实现太阳能转换与存储的理想方案，在解决能源与环境问题方面具有潜在的应用。水氧化是这两种能源光催化反应途径中最重要的半反应。本项目以理论太阳能转换效率达16%（按水分解产氢反应计算）、具有无偏压分解水能力的Ta3N5、LaTiO2N和LaTaON2三种材料构建高效稳定的光阳极，实现高效水氧化反应。主要研究：(1)高质量氮化物、氧氮化物光吸收薄膜制备方法；(2)高导电率、透明、稳定的Ti基保护层的制备方法及其对氧氮化物、氮化物光吸收层稳定性的改善机制；(3)廉价的Co、Fe、Ni基低结晶度体相电催化材料的制备方法及其对氧氮化物、氮化物光催化材料催化性能的改善机制。旨在为氧氮化物、氮化物光催化材料在高效分解水和还原CO2方面应用提供实验基础和科学指导。

项目重点发展了熔盐法制备氮化物、氧氮化物薄膜电极，揭示了载流子传输各向异性、表面态对光催化反应电荷分离、传输、分子活化等影响机制，提出了一种基于光腐蚀的直接分解气体分子的新方法，在密闭空间CO2移除供氧具有重要的应用前景。本项目在执行期间共计发表SCI论文40篇，其中影响因子大于10的论文17篇。在氧氮化物制备方面发表论文7篇，在界面调控和电荷传输机制方面发表论文33篇。申请发明专利4项。获得江苏省科学技术一等奖一项（项目负责人排名第三）。