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

Weiyu Xu,Muhammad Habib,Daobin Liu,Qi Fang,Shuangming Chen,Hengjie Liu,Xusheng Zheng,Ke Zhang,Li Song,Chuanqiang Wu

doi:10.3390/molecules21101318

Abstract

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.

Highlights

Growing industrialization and the immense use of energy which is usually obtained from fossil fuels create a significant harmful impact on the climate and human health
3, and MoO3 further reacted with HNO3 and was dissolved into the with HNO
3 and formed MoO3, and MoO3 further reacted with HNO3 and was dissolved into the solution

Summary

Introduction

Growing industrialization and the immense use of energy which is usually obtained from fossil fuels create a significant harmful impact on the climate and human health. The water splitting process can be divided into two half-processes [13], the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Because of the energy and dynamic barrier, to drive the reaction on, a potential higher than 1.23 V is essential. Between these two half-processes, OER is the bottleneck because of the multi-proton transfer process [14]. Iridium oxidate is the best catalyst for OER [13] but its practical uses suffers from high price and low earth abundance, while transition metal compounds can overcome these two disadvantages and can be a good substitution to catalyze the OER reaction according to the volcano plot [13]

Methods

Discussion

Conclusion