学　术

　　为搭建我校博士后之间的学术交流平台，促进学术水平提升，学校博士后管理办公室组织开展博士后学术沙龙活动。本次沙龙由我校博士后Raziq Fazal、Hussain Sajjad、黎波和Nasir Ilyas分享其研究成果，诚挚邀请感兴趣的师生参加。

　　一、时　间：2021年5月21日（周五）14：30

　　二、地　点：清水河校区经管楼宾诺咖啡

　　三、主办单位：电子科技大学博士后管理办公室

　　四、承办单位：物理学院

　　五、活动安排：

　　报告一：

　　（1）主题：Synthesis of Efficient Photocatalysts for Solar Fuels Production and Mechanism Discussion

　　（2）主讲人：Raziq Fazal  物理学院博士后

　　（3）交流内容：

　　The increasing challenges in energy and environmental concerns due to the consumption of fossil fuels have invigorated growing awareness in the past few decades. With industrialization and rapid growth of population, it is projected that the globe will require two-time current energy supply in near future. At present, the world’s energy demand largely depends on fossil fuels, such as petroleum, coal, and natural gas, which are rapidly being depleted. The consumption of fossil fuels inevitably leads to harmful gases emission that is detriment to the environment. As a result, novel discoveries and frontlines in material science and engineering have been pursued to overcome the obstacle for effective energy conversion and for environmental protection. Among various renewable energy projects, semiconductor based photocatalysis as a feasible technology, in which the inexhaustible and clean solar energy can be harvested, has gained considerable interdisciplinary attention. Therefore, it is of great significance to improve activities of semiconductor for efficient photocatalysis.

　　Here, we report the discovery of a photocatalyst composed of copper/gold (Cu-Au) nanoalloy grown on the organic polymeric g-C3N4 surface. The newly designed Cu-Au/g-C3N4 functional composite is extremely stable and displays unprecedented selectivity as well as productivity for CO2 conversion to CH4. Interestingly, the sample-optimized selectivity for CO2 conversion to CH4 is recorded to be 95% under visible light irradiation (360 µmol.g-1h-1).

　　Moreover, we have fabricated Au-modified reduced graphene oxide coupled with carbon nitride (Au/rGO/g-C3N4) as novel 0D/2D/2D photocatalytic nanocomposites. The optimized sample 2Au/0.6rGO/g-C3N4 exhibits exceptional visible-light activity for water splitting and CO2 reduction with quantum efficiency of 3.82 % and 1.98 %, respectively.

　　In addition, here we also successful synthesis of CdSe quantum dots (QDs) modified phosphorus doped g-C3N4 (P-CN) for advanced photocatalytic applications. Phosphorus doping and structural coupling with CdSe QDs are shown to significantly extend visible-light response of g-C3N4 up to 700 nm.

　　The current work provide a new strategy to design low-cost and sustainable photocatalysis with wide visible-light activity for practical overall water splitting and CO2 reduction applications

　　（4）主讲人简介：

　　Raziq Fazal was born in Pakistan in 1985. He has received his Ph.D. degree in Materials Science/Chemistry from Heilongjiang University in 2017. He joined School of Physics as a post-doctoral researcher in 2018, and promoted to research associate recently. Since 2018, he has led a photocatalysis research group of M.S. and Ph.D. students. His expertise is focused on photophysics and photochemistry of nanostructured materials. His current research interest is to develop efficient photocatalytic approaches to solar energy conversion (Water splitting/CO2 conversion) and utilization by harnessing solar energy to produce molecular fuels and to degrade environmental pollutants. As a first and co-author, he has published over 50 professional papers in the international SCI journals, such as “Adv Energy Mater”, “Chem Commun”, “Appl Catal B”, ACS Energy. Let, ACS Environ. Sci. Tech, Chem. Eng. J, J Hazard. Mater.  and “J Phys Chem C”. These papers have been positively cited for more than 1800 times. Since 2019, he has accepted the invitation from OAP Publishing House to join in the Editorial Board as part of the journal’s Advances in materials area of the Scientific World Journal.

　　报告二：

　　（1）主题：Wideband phased array antennas

　　（2）主讲人：Hussain Sajjad 物理学院博士后

　　（3）交流内容：

　　Over the past couple of decades, the wireless communication has become a critical part of our life, and the use of a range of mobile services is reaching incredible levels of demand. Therefore, communication systems are rapidly changing, with wideband antenna arrays considered as a key ingredient to realize high performance future wireless communications. Thus, the radio front-ends need to be smarter and cost effective to penetrate the commercial markets.

　　This seminar looks at an innovative approach to design wideband, wide-scan phased arrays based on current sheet array (CSA) technique. The talk briefly introduces the CSA concept and highlights associated design challenges. The major portion of seminar focuses on the design implementation of wideband phased arrays namely: Metasurface loaded dual-polarized phased array for 5G millimeter wave applications，A low-profile, wide-scan, cylindrically conformal X-band phased array, 6:1 all-metallic phased array

　　（4）主讲人简介：

　　Hussain Sajjad was born in Punjab, Pakistan, in 1986. He received the B.E. degree in electronic engineering from Air University (AU), Islamabad, Pakistan in 2008, and M.S. in wireless communications from University of Engineering and Technology (UET), Taxila, Pakistan in 2013. He earned PhD degree from school of electronic science and engineering UESTC in 2020. Currently he is working as post-doc research fellow at school of physics, UESTC, Chengdu, China. His research interests include phased array antennas with emphasis on terminal antenna, base station antenna.

　　报告三：

　　（1）主题：Improvement of laser damage resistance of fused silica by oxygen ion implantation

　　（2）主讲人：黎波 物理学院博士后

　　（3）交流内容：

　　Under ultraviolet (UV) laser irradiation, oxygen loss occurs in the fused silica optics used in the high power laser facility for the research of inertial confinement fusion (ICF), which will lead to the significantly increased number of structural defects in fused silica surface such as oxygen vacancy. As a result, the initial damage threshold and damage growth threshold of fused silica will reduce and the damage growth coefficient will increase. This has become the bottleneck problem that restricts the high-flux output of the laser facility and there is no effective solution at present. Ion implantation technique can be utilized to provide oxygen ions in the surface of fused silica, which will recombine the oxygen-deficiency defects and compensate for the oxygen deficiency. As a result, the laser damage resistance of fused silica will be improved. Firstly, the influence of ion implantation parameters on the chemical composition and defect distribution of fused silica surface is calculated theoretically to obtain optimized parameters. Then the oxygen ion implantation is carried out on fused silica. The effects of ion implantation parameters on the Si/O stoichiometric ratio, structural defects, optical properties and laser damage performance of fused silica are investigated systematically. Therefore, appropriate concentration of oxygen can be obtained by adjusting the process parameters to recombine the oxygen-deficiency defects and compensate for the oxygen deficiency under the laser irradiation. This will provide theoretical and technical support to improve the laser damage resistance performance of fused silica and extend its lifetime.

　　（4）主讲人简介：

　　Bo Li obtained the Ph.D. degree from the University of Electronic Science and Technology of China in 2019. He currently works as a postdoctoral researcher in the School of Physics, UESTC. His main research interest is the interaction between laser, ion beam and materials.

　　报告四：

　　（1）主题：Resistive Switching Devices for Information Sensing and Memory Processing

　　（2）主讲人：Hussain Sajjad 物理学院博士后

　　（3）交流内容：

　　The continued growth in data storage and processing demand has spurred the development of high-performance storage technologies and brain-inspired neuromorphic hardware. Moreover, unlike the algorithm-based methodologies, hardware-type neuronal networks (HNNs) can be a better option for implementing the next-generation artificial intelligent computing processor, possibly due to low power consumption and efficient space usage. Resistive random-access memory (RRAM) is a promising technology to develop nonvolatile memory and artificial synaptic devices for brain-inspired neuromorphic computing. Here, I present the electrically, optical, and electrically/optically triggered synaptic devices that were developed for intelligent and energy-efficient neuromorphic computing. Our newly fabricated memory devices may enable the development of nonvolatile memory and realize controllable resistance/weight modulation when applied as an artificial synapse for neuromorphic computing.

　　（4）主讲人简介：

　　In 2020, Nasir Ilyas received his Ph.D. from the School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China. Following that, he joined School of Physics as a postdoctoral fellow. His current research interests include designing, fabrication, and investigating novel properties of electronic and optoelectronic devices, emphasizing memory and neuromorphic applications.

　　　　　　　　　　　　　　　　　电子科技大学博士后管理办公室

　　　　　　　　　　　　　　　　　　　　　2021年5月18日