2D materials for sustainable word: electrocatalysis, low-power device and machine learning
二维材料：构筑清洁能源和低能耗的美丽新世界
Zeng Liu（刘政）
ABSRACT
Using green energy or increase energy efficiency is the key to a sustainable world. I will introduce the potentials of 2D materials to build a sustainable world in terms of low-cost H2 generation, low-power-consuming devices, and IA enabled optimization of novel materials. Semiconducting catalysts are great candidates to replace noble metal to make green energy such as H2 due to their low cost. Using 2D materials as the model system, we have revisited the semiconductor-electrolyte interface and unraveled a universal self-gating phenomenon through micro-cell based measurements [1]. We unveiled a surface conductance mechanism that dominates the charge transport in semiconductor electrocatalysts. Based on this, we provided a guideline on how to design high-performance semiconductor electrocatalyst. Apart from the generation of green energy, we are also using 2D materials to build next-generation CMOS architecture, such as negative capacitance field-effect transistors, which may dramatically reduce the consumption of energy [2]. Finally, I will discuss our recent progress on the machine learning guided materials synthesis, as well as the novel design of neural networks hardware based on 2D materials [3].
方面，展现二维材料在此过程中发挥的独特的作用：
1) 在清洁能源方面，氢能源一直备受青睐。由于传统贵金属，比如Pt制氢的成本高昂，基于半导体材料的电化学析氢被广泛研究。利用二维半导体材料作为模型催化体系，以及自制的微电化学系统，我们对其电解液和半导体催化剂界面的电荷输运做了细致研究，发现电催化过程自发诱导的表面电导是制约半导体催化剂性能的重要因素，此过程依赖于催化剂载流子类型以及厚度。基于此，针对不同催化反应，我们提出半导体材料的筛选策略，以此获得高性能半导体催化剂。
2) 在能效方面，信息与通讯行业成为全球第五大耗能产业，其能耗及碳排放数量占全球总量的2%- 4%，其中主要用于硅基晶体管的运算。我们利用二维材料构建了新型的二维负电容晶体管，希望突破传统硅基电子器件的热力学极限，提升电子器件的能源利用效率。除此之外，人工智能的发展也为解决能效问题提供了新的思路。最近，我们将其应用于材料合成，发现 人工智能可以显著的降低新材料合成和优化周期，大大提升材料生产效率。
BIOGRAPHY
Associate Professor Liu Zheng is an associate professor at MSE and EEE, NTU. He works on the synthesis of high-quality and large-size novel 2D monolayers, especially transition metal dichalcogenides (TMDs) and their applications in electronics and catalysis.
Dr. Liu is the recipient of the finalist of the World Technology Award in Energy category, Singapore NRF Fellowship, NTU Nanyang Assistant Professorship, ICON-2DMAT Young Scientist Award, Singapore Young Scientist Award (YSA), Asia’s Rising Scientists, Nano Research Young Star Editors, Nanyang Research Award and Highly Cited researcher. He held the Materials Research Society of Singapore Chair Professorship at NTU.
刘政教授于2005 年本科毕业于南开大学，2010 博士毕业于中科院国家纳米中心，之后在美国Rice 大学进行博士研究。2013年年底，入职新加坡南洋理工大学材料科学与工程学院和电子电气工程学院。现任南洋理工大学材料科学与工程学院副教授、新加坡材料学会讲席教授。目前的主要研究方向为二维材料的合成以及器件和能源方面的应用。
所获奖项包括：世界科技奖能源类最终提名，新加坡国立基金会会士， 南洋助理教授，新加坡青年科学家奖，ICON-2DMAT青年科学家，Asia’s Rising Scientists, Nano Research Young Star Editors，南洋研究奖，高被引科学家等。