/   Home   /   Newsroom   /   Research News

Researchers Reveal Ultrahigh Electrochemical Sensing of Heavy Metal Ions via Defect and Phase-Engineering

Aug 27, 2018     Email"> PrintText Size

In a paper published in Chemical Communications, the research group jointly led by Prof. HUANG Xingjiu from Institute of Intelligent Machines, Hefei Institutes of Physical Science prepared Mn-MoS2 Nanosheets for ultrasensitive electrochemical detection of heavy metal ions.

The team found for the first time that chemical interactions between Pb(II) and actived S atoms in Mn-MoS2 facilitate the electron transfer and in situ catalytic redox reactions.

Using nanomaterials to modify the electrochemical electrode is an effective method to improve the electrochemical-sensing performance. There is no doubt that adsorption capability plays a significant role in electrochemical detection.

However, previous work mostly focused on enhancing the electrochemical-sensing performance via increasing the adsorption capability while ignoring the interaction mechanism between active sites and analyte. The mechanism remains unclear—particularly the difference in effect on electron transfer and catalysis between physical and chemical interactions, which limits the development of electrochemical sensing.

In this work, the team reported an ultrahigh Pb(II) electrochemical sensing via Mn-mediated MoS2 nanosheets.

The chemical interaction between Pb(II) and S atoms was caused by defect- and phase-engineering—these were significant factors. The EXAFS results demonstrated that single Mn atoms were successfully doped into the MoS2 nanosheets via substitution of Mo sites.

A new phase, 1T-MoS2, emerged after Mn-mediating in pure 2H-MoS2. The heteroatom Mn could destabilize the lattice and introduce S vacancy defects, accompanied by an S plane that might glide due to the electron-donating nature of Mn.

The rich S vacancy and distinct 1T-phase-embedding give Mn-MoS2 good electronic properties. Due to the stimulated activity of S atoms, chemical interactions (Pb-S bonding) were found between Pb(II) and Mn-MoS2.

This suggested that the stronger chemical effects facilitate the electron transfer and significantly promote in situ reduction and re-oxidation relative to the weak physical adsorption interactions.

These findings stimulate new opportunities for enhancing the electrochemical sensitivity and for investigating the atomic-level electrochemical behavior by defect- and phase-engineering.


Fig. 1 The influence of physical and chemical interaction on electron transfer. (Image by ZHOU Wenyi) 


(Editor: ZHANG Nannan)

Related Articles

anopattern;self-assembly;vacancy;ion irradiation;surface facets

Nano-dunes with the Ion Beam: New Method for Self-organized Nanostructures

Sep 09, 2015

Dr. Stefan Facsko from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Dr. Xin Ou from the Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, have now demonstrated a method for self-organization of na...

electrochemical detection;As(III);drinking water;nanocube;monolayer;nanoparticle

IIM Researchers Reveal the Surface Defects Enhancing Electrochemical Detection of As(III)

Dec 18, 2017

Recently, the study team jointly led by Prof. HUANG Xingjiu from Institute of Intelligent Machines, Hefei Institutes of Physical Science, designed highly sensitive electrochemical detection of As(III) in drinking water by Co 0.6 Fe2.4

electrochemical detection; surface-electronic-state-modulation; semiconductor; TiO2 Nanosheet; oxygen vacancy

New Discovery: Synergetic Catalysis of Oxygen Vacancy at Single-Crystalline (001) TiO2 Nanosheets

Mar 14, 2017

A research group led by Prof. LIU Jinhuai and Prof. HUANG Xingjiu at Institute of Intelligent Machines, Hefei Institutes of Physical Science reported their discovery in detecting Hg(II) through TiO2-based electrode without other modification...

Contact Us

Copyright © 2002 - Chinese Academy of Sciences