2D Ti3C2Tx flakes prepared by in-situ HF etchant for simultaneous screening of carbamate pesticides

Ankita Sinha; Kaixin Ma; Huimin Zhao

doi:10.1016/j.jcis.2021.01.063

2D Ti₃C₂T_x flakes prepared by in-situ HF etchant for simultaneous screening of carbamate pesticides

J Colloid Interface Sci. 2021 May 15:590:365-374. doi: 10.1016/j.jcis.2021.01.063. Epub 2021 Jan 27.

Authors

Ankita Sinha¹, Kaixin Ma¹, Huimin Zhao²

Affiliations

¹ Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China.
² Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, PR China. Electronic address: zhaohuim@dlut.edu.cn.

PMID: 33549895
DOI: 10.1016/j.jcis.2021.01.063

Abstract

Present work reports preparation of colloidal single/few layer Ti₃C₂T_x MXene flakes using minimally intensive layer delamination (MILD) method for rapid electroanalytical screening of carbamate pesticides. Lithium fluoride salt and hydrochloric acid (7.5 M LiF/9M HCl) was used to produce in-situ generated HF as etchant to remove Al successfully from Ti₃AlC₂ MAX phase. Unlike the clay method (5 M LiF/6M HCl), this methodology simplified Ti₃C₂T_x synthesis protocol resulting in Li⁺ ions intercalated Ti₃C₂T_x which was delaminated without further sonication. The delaminated Ti₃C₂T_x flakes were found to be single/few layered sheets with mostly -OH and -O terminated surface groups. The characteristic 002 peak observed in X-ray diffraction (XRD) at 2θ = 6.4° with interplaner distance of 1.1137 nm suggested broadening of the peak attributed to the presence of Li⁺ ions between Ti₃C₂T_x flakes. Delaminated Ti₃C₂T_x flakes were utilized as working electrode which demonstrated simultaneous and selective detection of carbamate pesticides methiocarb and diethofencarb by voltammetry. The oxidation peaks of the two pesticides were well separated by a potential difference of 0.35 V in 0.5 M H₂SO₄ and DPV detection limits were calculated as 0.19 μg mL^-1 and 0.46 μg mL^-1 for methiocarb and diethofencarb respectively. Ti₃C₂T_x flakes as electrochemical sensor exhibited long term stability and acceptable recoveries in real sample for environmental applications.

Keywords: Delamination; Diethofencarb; Layered materials; Methiocarb; Ti(3)C(2)T(x); Voltammetry.