时间：2018年11月30日（周五）中午12点30分
地点：北洋园校区化工学院50楼A333教工之家(咖啡厅)
报告题目：主题研讨：水变油居然不是惊天骗局
主讲人：王拓于一夫
【个人简介】
王拓，天津大学化工学院教授，博士生导师，国家优青，天津市杰青。王拓以“薄膜沉积的化工基础及应用”为研究主线，建立了载气流型、前驱体传质等因素与薄膜性质、结构之间的关系，实现了薄膜的可控掺杂和纳米结构精细构筑，形成了一套基于化学气相沉积的薄膜可控制备方法。近年来将薄膜沉积应用于光解水制氢电极的制备，构建了光生电荷的高效传输通道，拓宽了电极的吸光范围，发展了表面反应的调控方法。共发表SCI论文71篇，他引3000余次。以第一/通讯作者在JACS、EES、Angew Chem Int Ed、Adv Mater、Chem Sci、Chem Soc Rev等重要SCI期刊发表论文30篇，平均影响影子10.85，4篇入选ESI高被引论文。研究成果4次被Materials Views等学术媒体报道。获授权中国专利25项，美国专利1项。
于一夫，天津大学理学院副教授，博士生导师。于一夫以“可控化学转化构筑新型催化材料”为研究主线，发展了离子交换、界面反应、原位自组装等转化手段，实现了催化材料微观结构的精细调控，构筑了一系列具有可控单一变量的模型催化剂，揭示了目标结构参数与催化性能之间构效关系。已在Nature Chem.（2篇）、Acc. Chem. Res.、J. Am. Chem. Soc.（3篇）、Angew. Chem. Int. Ed.（5篇）、Adv. Mater.（4篇）、ACS Catal.（2篇）等期刊上共发表论文40余篇，他引1700余次，6篇论文入选ESI高被引论文（2篇ESI热点论文）。研究成果获得Science、Inorg. Chem. Front.等期刊的highlight评述。
【报告内容简介】
【王拓报告：水变油居然不是惊天骗局】“水变油”似乎一直让人想到“骗局”。从美国人Stanley Meyer（1996被起诉，1998年离奇死亡），到我国的王洪成（1997年获刑十年），再到1996年基努·里维斯主演的科幻惊悚影片《连锁反应》，“水变油”的话题从来不缺乏争议。然而，基于半导体的光电化学（PEC）水分解制氢技术，却实实在在是获得氢能的理想途径之之一。但是，该过程的效率距离大规模应用仍有较大的差距。导致光解水效率低下的原因，主要是由于光电极材料（如Fe2O3）中的电荷分离效率较低，以及一些高性能光电材料（如Si、CIGS）自身固有的易腐蚀特性。本研究以原子层沉积（ALD）为表面调控手段，提升窄禁带Fe2O3基光解水阳极的电荷分离效率，并增CIGS、Si等窄禁带阴极半导体材料的耐腐蚀性能。基于ALD在三维纳米棒表面沉积共形包覆薄膜的特点，制备了Fe2O3/ZnFe2O4和Fe2O3/Fe2TiO5三维异质结，并形成了高质量的界面，有效增强了Fe2O3中的光生电子-空穴分离效率。另一方面，基于ALD可以沉积高质量无孔洞薄膜的特点，提升CIGS和Si电极的抗腐蚀能力，并对其界面缺陷进行有效修复。其中，CIGS电极的光能转化效率可达9.3%。本研究展示了通过半导体电极来高效获得“太阳能燃料”的可能性。
【于一夫报告：如何分解水获取新能源？】通过太阳能或可再生能源转化得到的电能催化水分解，被认为是获得氢能的最理想途径之一。目前，光/电催化水分解制氢的能量转化效率较低，距离大规模应用仍有较大差距。催化材料的性能是由其电子结构、原子结构、微观结构和宏观结构等多级结构参数决定。理解不同结构参数与催化性能之间构效关系对发展新型催化材料、进一步提高光/电水分解制氢效率至关重要。但是，传统“自下而上”和“自上而下”合成方法在调节催化材料某一结构参数的同时不可避免会引起其它结构参数的变化，从而干扰了目标结构参数研究。化学转化策略采用固体材料为起始材料，通过化学反应将其转化为目标材料。由于其独特的制备路径，允许我们调控特定结构参数，为针对性的研究目标参数与催化性能之间构效关系提供可能。于一夫等人发展了离子交换、界面反应、原位自组装等化学转化手段，构筑了一系列具有可控单一变量的模型催化剂，揭示了晶相、带隙、缺陷、电子结构等因素与催化性能之间关系。
【相关学科】化学、化学工程与工艺、材料科学与工程、可再生能源以及相关研究领域
【主办单位】校工会、图书馆、科研院、校青年教师联谊会、学生创新实践协会
Lecture:
When: 12:30 p.m., Friday, 11/30/2018
Where: A333, 50 Building, School of Chemical Engineering and Technology, Beiyang campus.
About the Lecture:
A common myth about water fuel is the fraud of Stanley Meyer (sued 1996, died suddenly 1998) and the 1996 sci-fi movie Chain Reaction starring Keanu Reeves. However, solar water splitting based on photoelectrochemical (PEC) cells is indeed one of the ideal routes to obtain sustainable hydrogen as the energy for the future. But the efficiency of this process is far below what is expected for real application. The reason for this includes 1) the carrier transport efficiency is very low for stable narrow bandgap semiconductors, mainly oxides such as Fe2O3, while those with high charge carrier transport efficiency (such as Si, CIGS, etc.) suffer from severe corrosion issues in aqueous electrolytes. In this study, we use atomic layer deposition (ALD) as an enabling tool to improve the charge separation efficiency for narrow bandgap Fe2O3, and improve the anti-corrosion ability of CIGS and Si photoelectrodes. Based on the conformal coating ability of ALD, 3D heterojunction of Fe2O3/ZnFe2O4 and Fe2O3/Fe2TiO5 have been fabricated, forming high quality interfaces for effective separation of electron-hole pairs. On the other hand, enabled by the pin-hole free layer deposited by ALD, protective layers for CIGS and Si photoelectrodes have been fabricated for stable PEC water splitting operations, where the ALD films could also serve as the passivation layer to remove interfacial defects. An applied bias photon-to-current conversion efficiency (ABPE) of 9.3% could be obtained with TiO2 protected CIGS photocathodes. This work demonstrates the great potential of semiconductor photoelectrodes for effective solar-to-fuel energy conversion.
The properties of inorganic catalysts are determined by their multilevel structure, including electronic structure, atomic structure, microstructure and macrostructure. The understanding of function of each structure parameter is fundamental to revealing catalysis mechanism and then developing high efficient catalysts. However, different structural parameters in inorganic catalysts obtained by conventional synthesis methods usually simultaneously alter with the change of preparation conditions, increasing the difficulty to establish the precise relationship between target parameter and catalysis property. Hence, the development of novel synthesis strategy to control single variable in catalysts is of crucial importance. Of note, chemical transformation strategy, which makes use of various chemical processes to transform starting materials into target materials, shows promising potential in producing ideal model catalysts with well-defined single structural variable. Yifu Yu et al. have been focused on chemical transformation synthesis of advanced inorganic catalysts with single structural variable and understanding their structure-property relationships. They have developed several transformation strategies to prepare a series of model catalysts, in which the function of composition, defect, crystal phase, band gap and electronic density is clearly revealed.
Relevant Discipline: Chemistry, Chemical Engineering and Technology, Materials Science and Engineering, Renewable energy and other related research areas
Organizers: Trade Unions, Library, Office of Science and Technology, Young Teachers Association, Student Association of Innovation and Practicums
All students and staff of Tianjin University are welcome.
