Growing and Etching MoS₂ on Carbon Nanotube Film for Enhanced Electrochemical Performance.

In this work we directly synthesized molybdenum disulfide (MoS₂) nanosheets on carbon nanotube film (MoS₂@CNT) via a two-step chemical vapor deposition method (CVD). By etching the obtained MoS₂@CNT into 10% wt HNO₃, the morphology of MoS₂ decorated on CNT bundles was modulated, resulting in more catalytic active MoS₂ edges being exposed for significantly enhanced electrochemical performance. Our results revealed that an 8 h acid etching sample exhibited the best performance for the oxygen evolution reaction, i.e., the current density reached 10 mA/cm² under 375 mV over-potential, and the tafel slope was as low as 94 mV/dec. The enhanced behavior was mainly originated from the more catalytic sites in MoS₂ induced by the acid etching treatment and the higher conductivity from the supporting CNT films. Our study provides a new route to produce two-dimensional layers on CNT films with tunable morphology, and thus may open a window for exploring its promising applications in the fields of catalytic-, electronic-, and electrochemical-related fields.