Font Size: a A A

Laser Etched Graphene-based Sensor And Its Application In Trace Heavy Metal Detection

Posted on:2020-02-16Degree:MasterType:Thesis
Country:ChinaCandidate:X N LinFull Text:PDF
GTID:2381330590984700Subject:Analytical Chemistry
Abstract/Summary:PDF Full Text Request
With the rapid development of China's industrialization,heavy metal pollution has seriously jeopardized people's health due to its high toxicity and non-biodegradability.Therefore,finding a simple,efficient and sensitive detection method is one of the prerequisites for the treatment of heavy metal pollution.Electrochemical methods,especially anodic stripping voltammetry,have attracted extensive attention in the field of heavy metal detection because of their fast response,easy operation,high sensitivity,and the ability to achieve on-site monitoring.In this paper,a new method,namely laser etching method,was used to prepare graphene-based carbon nanomaterials and a novel heavy metal sensor was constructed.It provided an effective method for the determination of trace heavy metal ions in water.The main research work is as follows:?1?A new method was provided to prepare laser-etched graphene-based carbon nanomaterials?LEGCNs?by laser etching polyimide?PI?films directly.By scanning electron microscopy?SEM?,X-ray diffraction?XRD?and Raman spectroscopy confirmed that LEGCNs have stacked multilayer graphene nanosheet structures.Herein,they were modified on the surface of GCE,and combined with in-situ bismuth film modification?BF?to successfully prepare the bismuth film-laser etched grapheme-based carbon nanomaterials modified glassy carbon electrode?BF-LEGCNs/GCE?.Then the detection parameters were optimized by SWASV and showed satisfactory responses for the simultaneous determination of cadmium?Cd?II??and lead?Pb?II??.For Cd?II?,its wide linear range from 7 to 120?g?L-1 and the detection limit is 0.47?g?L-1.For Pb?II?,the linear range is 5 to 120?g?L-1 and the detection limit is 0.41?g?L-1.In addition,the electrochemical properties of BF-LEGCNs/GCE,such as repeatability,reproducibility,selectivity and stability,were also evaluated.Finally,BF-LEGCNs/GCE was successfully applied to the simultaneous determination of Cd?II?and Pb?II?in water.The results showed that the laser etching technology is an effective tool for preparing graphene-based carbon nanomaterials with excellent electrochemical performance.?2?An approach based on laser etching technique was established to fabricate high-quality3D porous nitrogen-doped laser etched graphene-based carbon nanomaterials?N@LEG?with quite wide detection ranges via introducing of polyaniline?PANI?and polyvinylpyrrolidone?PVP?as N-dopant.The N@LEG combines the advantages of the unique electrochemical properties and the 3D porous framework structure with large electrochemical active surface areas of LEG with the strong metal ions affinity of N atoms.After optimizing conditions by SWASV,N@LEG modified glassy carbon electrode?N@LEG/GCE?with an in-situ plated bismuth film,exhibited fairly wide linear detection ranges varying from 5 to 380?g?L-1 and the detection limits is 1.08?g?L-1 for Cd?II?;and for Pb?II?is 0.5 to 380?g?L-1 and the detection limit is 0.16?g?L-1,respectively.At the same time,the sensitivity,selectivity,anti-interference,reproducibility,reproducibility and stability of N@LEG/GCE were also studied.
Keywords/Search Tags:Electrochemical detection, Cyclic voltammetry (CV), Electrochemical impedance spectroscopy(EIS), Raman, Modified electrode
PDF Full Text Request
Related items