Layered materials and derived 2D material couples such as graphite/graphene, layered and single layer pnictogens (i.e., black phosphorus and phosphorene) and transition metal dichalcogenides (TMDs) have gained a lot of attention due to their electrocatalytic properties and as potential materials for energy storage. Previous studies have shown that electrochemical reactions at graphite, MoS2 and pnictogens mainly occur at the edges and steps of crystals rather than on the basal plane. The persisting question is if this is a general trend in nature within bulk crystals of 2D materials. To come closer to the answer to this question, we studied the surface of artificially grown TiS2 and TiSe2 crystals regarding their local electrochemical activity via scanning electrochemical microscopy (SECM). Both TMDs have shown increased electrochemical activity near crystal steps/edges. For correlation, optical and topographical analysis were performed via scanning electron microscopy (SEM) and atomic force microscopy (AFM). We show that the increased electrochemical activity at edges is persistent for these layered crystalline materials, thus expanding the knowledge their properties, which is important for future application in the energy sector.
Bibliographical noteFunding Information:
M.P. acknowledges the financial support of Grant Agency of the Czech Republic (EXPRO: 19-26896X ). S.W. would like to thank the Bayerisch-Tschechische Hochschulagentur for financial support (Project: BTHA-MOB-2020-10 ). C.I. acknowledges the financial support by the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 888797 . K.A.N. acknowledge the financial support from Quality Internal Grants of BUT (KInG BUT) (Reg.No. CZ.02.2.69/0.0/0.0/19_073/0016948 ), financed from the OP RDE. The authors gratefully acknowledge the CzechNanoLab project LM2018110 funded by MEYS CR for the financial support of the measurements/sample fabrication at CEITEC Nano Research Infrastructure.
© 2021 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Materials Science(all)