Simple and Large Scale Construction of MoS2-g-C3N4 Heterostructures Using Mechanochemistry for High Performance Electrochemical Supercapacitor and Visible Light Photocatalytic Applications

Sajid Ali Ansari,Moo Hwan Cho

doi:10.1038/srep43055

Abstract

The design of heterojunctions for efficient electrochemical energy storage and environmental remediation are promising for future energy and environment applications. In this study, a molybdenum disulfide-graphitic carbon nitride (MoS2-g-C3N4) heterojunction was designed by applying simple mechanochemistry, which can be scaled up for mass production. The physical-chemical and photophysical properties of the as-prepared MoS2-g-C3N4 heterojunction were analyzed using a range of characterization techniques. The supercapacitance performance was determined by electrochemical half-cell measurements, and visible light-induced photoelectrochemical and photocatalytic performance was studied using photocurrent and model organic pollutant degradation experiments. The resulting MoS2-g-C3N4 under the optimized experimental conditions showed significantly higher photocatalytic activity and photoelectrochemical performance under similar visible photoirradiation conditions compared to the bare materials. The resulting heterostructure electrode delivered a higher capacitance of 240.85 F/g than the bare material (48.77 F/g) with good capacitance retention. The superior performance was attributed mainly to the robust light harvesting ability, improved charge separation, high surface area, increased mass transfer, and capacitive and conductive behavior. The convenient and mass production of heterojunctions using a simple and cost-effective method will provide a good example for the efficient design of visible light active photocatalysts and capacitor electrode materials for environmental remediation and energy storage device applications.

Highlights

(TiO2), have been reported to be photoactive catalysts for the degradation of organic pollutants, but their photocatalytic applications in the visible light region have been hindered by their wide band gap and high rate of photoinduced electron/hole recombination[1,2,3,4,5]
Two-dimensional molybdenum disulfide (MoS2) dichalcogenide, which is comprised of Mo metal layers sandwiched between two sulfur layers and stacked together by weak van der Waals interactions has attracted a great deal of attention in the field of photocatalytic and energy storage applications owing to its excellent electrocatalytic performance, strong absorption ability in the visible region, narrow band gap, good conductivity, high theoretical specific capacitance, and good cycling stability[18,19]
The characteristic X-ray diffraction (XRD) peaks of MoS2 and g-C3N4 were visible in the XRD pattern of the MoS2-g-C3N4 heterostructure, which suggests that the content and reaction time are suitable for the successful formation of MoS2-g-C3N4 heterostructures

Summary

Introduction

(TiO2), have been reported to be photoactive catalysts for the degradation of organic pollutants, but their photocatalytic applications in the visible light region have been hindered by their wide band gap and high rate of photoinduced electron/hole recombination[1,2,3,4,5]. The impressive characteristics of supercapacitors, such as the immediate delivery of a higher power density with simultaneously shorter charging times, have attracted considerable attention in portable electronic device applications Owing to these characteristics, tremendous research efforts have been carried out to develop new www.nature.com/scientificreports/. Two-dimensional molybdenum disulfide (MoS2) dichalcogenide, which is comprised of Mo metal layers sandwiched between two sulfur layers and stacked together by weak van der Waals interactions has attracted a great deal of attention in the field of photocatalytic and energy storage applications owing to its excellent electrocatalytic performance, strong absorption ability in the visible region, narrow band gap, good conductivity, high theoretical specific capacitance, and good cycling stability[18,19]. Simple mechanochemistry-based methods are considered to be a good energy-saving technology and a highly efficient method for the design of heterostructures because of its potential to strengthen the interfacial interaction between the materials, reduce the layered thickness of the layered materials, lower the activation energy, and improve the material performance

Methods

Results

Conclusion