I-III-VI2族半导体纳米晶的可控制备及其光解水制氢性能研究

The conversion of inexhaustible solar energy into hydrogen energy through photocatalysis is the most effective means which to get rid of the dependence on fossil fuels, solve the two problems of energy crisis and environment pollution, and the development of high-efficiency photocatalyst is the key technology in this field. We consider the I-III-VI2 family semiconductors possess huge potential application in the field of photocatalytic hydrogen evolution because of their low-toxicity, high light capture capability and suited band gaps. With the help of nanomaterials preparation technology, this project intends to establish the synthetic strategy of several new I-III-VI2 family semiconductor nanocrystals with high-quality，and investigate their photocatalytic performance. Simultaneously, we will explore systematically the effects of different reaction conditions on the formation of final phase structures of I-III-VI2 family semiconductor nanocrystals, and then emphatically discuss the relationship between their phase structures and photocatalytic performance. On the basis of the above research, the I-III-VI2 family semiconductor nanocrystals which exhibited excellent performance are screened out, and recombined with non-noble metal cocatalys and carrier, and the analysis results of their synergetic mechanism further guide the optimization and modification of the surface structure of such materials. We consider this project could provide scientific basis and technical support for the application of I-III-VI2 family semiconductor in the field of photocatalytic hydrogen evolution.

利用廉价的太阳能通过光催化作用将水分解制得清洁的氢能是人类摆脱对化石燃料的依赖，解决能源危机和环境污染两大问题的最有效手段，而这其中的关键就是高效光催化剂的研发。I-III-VI2族半导体以其毒性低、光捕获能力强且带隙值匹配，在可见光解水制氢领域极具潜在应用价值。借助纳米合成技术，本项目拟开展建立高质量新型I-III-VI2族半导体纳米晶的制备方法学研究，并对其光催化性能进行考察和比较；同时系统探索不同反应条件对于I-III-VI2族半导体纳米晶最终相结构形成的影响规律，并据此深入讨论其相结构与光催化性能间的构效关系。在此基础上，筛选出性能优异的I-III-VI2族半导体纳米晶光催化剂，并选择非贵金属助催化剂或载体与之复合，分析它们之间的协同催化机制，进而指导对此类材料表面结构的优化改性研究。该项目的开展可为I-III-VI2族半导体在光解水制氢领域的应用提供重要的科学依据和技术支撑。

I-III-VI2族半导体材料由于具有毒性低、光捕获能力强、带隙值匹配且调节手段多样等优势，在光催化应用领域极具潜在应用价值。本课题借助纳米材料合成技术，开展了基于Ag-Ga-VI2类半导体纳米材料的制备路线的优化研究；初步考察了物相结构对其光催化性能的影响规律；系统研究了一种分子级一维无机金属卤化物，并将其作为助催化剂或载体用于I-III-VI2族纳米晶复合材料的设计。项目取得的主演研究成果包括：1）开发出简单的合成路线，能够在2 min内快速制备出高质量AgGaS2及AgGaS2/ZnS量子点，并且其带隙值能够在1.90 eV到2.98 eV的整个可见光区范围内被有效调控；2）实现了对AgGa(S1-xSex)2合金纳米晶在四方相及正交相间的可控制备，具有四方相结构及适宜带隙值的AgGa(S0.7Se0.3)2在90分钟内对甲基紫的可见光降解率达88.48%；3）采用胶体化学法快速制备出具有分子级一维结构的Cs3Cu2Cl5，理论计算结果表明其荧光发射机制可归因于激发态结构弛豫及缺陷态诱导的共同作用，微秒级的荧光寿命表明载流子在沿一维[Cu2Cl5]3-阵列具有快速的迁移率，使其有望作为电子转移材料，实现I-III-VI2光生电子-空穴的有效分离。本课题属于纳米光电材料类基础研究，开发出的高质量Ag-Ga-VI2类半导体纳米晶的可控快速合成路线，为此类材料的工业化生产提供了新的技术途径，具有十分重要的现实意义。此外，将无机金属卤化物引入基于I-III-VI2族纳米晶复合物的设计，为进一步提高其光催化性能提供了新策略，具有十分重要的科学意义。