Hydrogen evolution reaction (HER) based-on MoS2 and rolled-up nanomembranes

Date

Aug 28, 2018

Time

1:00 PM - 2:00 PM

Speaker

Jiang Qu

Affiliation

IFW Dresden

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Kristina Krummer-Meier

Description

Electrocatalysts play a key role in energy conversion technologies towards sustainable, fossil-free pathways to produce fuels and chemicals of global importance, because they can increase the reaction rate, efficiency, and selectivity of the chemical transformations involved.[1] One prospective goal is to develop electrochemical conversion processes that can convert water (H2O) in the atmosphere into higher-value products (H2). Active catalysts are required to minimize the overpotential which is necessary to drive the hydrogen evolution reaction (HER; 2H+ + 2e- -> H2)[2-3]. MoS2, a star 2D material, has been proved its promising application in HER and once it was the most active non-precious metal HER catalyst.[4-5] A geometric area-normalized current density of 10 mA.cm-2 has been achieved at from 150 to 200 mV overpotential by doping, strain-vacancy, and phase transition.[6-8] In order to further improve HER based on MoS2, hetero-material systems, e.g. MoS2/MoP, have drawn much attention due to their higher HER performance. However, to date the results of MoS2/MoP systems from chemists and material scientists are confused by a puzzle, i.e., which form of the material leads to the excellent HER performance, MoS2(1-x)Px compounds or MoS2@MoP heterojunctions?[9-11] Therefore, it is of vital importance to develop on-chip micro chemical reactors to reveal the fundamental nanoscale mechanisms of 2D materials in HER. Furthermore, such prototype of on-chip HER setup will provide an efficient platform for developing microengine based on HER. In this seminar, I will introduce my research progress on on-chip HER. An integrated micro chemical reactor platform has been built up and a series of devices with different structure (MoS2(1-x)Px compounds or MoS2@MoP heterojunctions) have been fabricated. By smartly combining microfabrication and chemical process, the puzzle of MoS2/MoP material in HER field was disentangled. The geometric area-normalized current density of 10mA.cm-2 with an overpotential of 40 mV, a world leading value for all non-precious metal catalysts, has been achieved in a micro reactor of HER which was treated with O2 plasma and phosphorization. It is proved that the excellent HER performance of MoS2/MoP is ascribed to the structure of MoS2(1-x)Px compounds. Moreover, by integrating with rolled-up metal nanomembranes,[12] the vacancies in 2D materials which are critical for HER can be tuned by the curling of 2D materials in rolled-up microtubes. The investigation of HER with 2D materials in integrated tubular reactors and the exploration of applying 2D materials in microengines will be performed during the next steps of works. References [1] Seh et al., Science, 355, 4998–5009 (2017). [2] Y. Jiao, et al. Chem. Soc. Rev. 44, 2060–2086 (2015). [3] J. D. Benck, et al ACS Catal. 4, 3957–3971 (2014). [4] G. Li, et al. J. Am. Chem. Soc. 138, 16632–16638 (2016). [5] H. Jin, et al. Chem. Rev., 118 (13), pp 6337–6408 (2018). [6] J. Deng, et al. Energy Environ. Sci., 8, 1594 (2015). [7] H. Li, et al. Nature Materials, 15, 48–53 (2016). [8] Y. Yu, et al. Nature Chemistry 10, 638–643(2018). [9] J Kibsgaard, et al. Angew. Chem. Int. Ed. 53, 14433–14437 (2014). [10] R. Ye, et al. Adv. Mater. 28, 1427–1432 (2016). [11] A. Wu, et al. Nanoscale, 8, 11052-11059 (2016). [12] Mei, Y. , Huang, G. , Solovev, A. A., Ureña, E. B., Mönch, I. , Ding, F. , Reindl, T., Fu, R. K., Chu, P. K. and Schmidt, O. G. Adv. Mater., 2008, 20: 4085-4090.

Links

• Seminars at the IFW

Last modified: Aug 28, 2018, 2:06:07 AM