[electrochemistry] Professor Yan Jiawei of Xiamen University and his collaborators have made new progress in the field of ionic liquid electrochemical interface research

Professor Yan Jiawei, School of chemistry and chemical engineering, Xiamen University, cooperated with Professor Feng Guang, School of energy, Huazhong University of science and technology, and Professor Alexei a kornyshev, Imperial College of technology, UK From the perspective of experiment and theoretical simulation, the electrochemical method and molecular dynamics simulation were used to study the electrochemical interface of ionic liquids, and important progress was made Relevant achievements were published in nature communications (DOI: 10.1038 / s41467-018-07674-0) under the title of "mining the electricity of water from human ionic liquids ones" Reducing the negative effect of water in the damped ionic liquid is the key problem to be solved Using molecular dynamics simulation, Professor Feng Guang found that the electrode materials have no obvious effect on the water adsorption, but the hydrophobic properties of ionic liquids can greatly change the water adsorption behavior on the electrode surface Professor Yan Jiawei used electrochemical method to confirm that for hydrophobic ionic liquids, even the presence of a small amount of water (3815 ppm) will significantly reduce the electrochemical window of the ionic liquid; for hydrophilic ionic liquids, even if the water content is as high as 22800 ppm, the electrochemical window of the ionic liquid is still not significantly reduced Carbon electrode and gold electrode show the same trend A variety of ionic liquids made up of different anions and cations all conform to this law In a word, the hydrophilicity / hydrophobicity of ionic liquid is the breakthrough point in this work It is found that the hydrophilicity ionic liquid can effectively prevent the water in the damped ionic liquid from adsorbing on the negative electrode surface The results show that the micro mechanism is that the van der Waals and electrostatic interactions from the electrodes and ionic liquids determine the existing state of water The above research results provide a new design idea for the application of ionic liquids in practical devices such as energy storage devices The research work was supported by NSFC projects (51876072, 21673193, 21533006, 21621091 and 21727807) The electrochemical experiment was completed by Liu Shuai, a master student.