Preparation And Application Of Biomass Waste Derived Carbon Nanomaterials Based Electrochemical Sensors

Due to the relatively low-cost and excellent electrocatalytic performance,carbon-based nanomaterials have been widely used in electrochemistry.In recent years,based on the advantages of biomass（such as environment-friendly,renewable,low-costandabundant）,the biomass was used as carbon source to prepare carbon nanomaterials,which has been widely used in the fields of electrochemical sensor,lithium-ion battery and supercapacitor.In this paper,two kinds of new carbon nanomaterials were prepared by using waste shaddock peels andokara as raw materials,and based on the excellent electrocatalytic properties of the materials,electrochemical sensors were constructed.（1）We reported the synthesis of carbon nanoballs aggregation networks-based aerogels（CNANAs）from the biomass waste of shaddock（Citrus maxima）peels for electrochemical sensor fabrication.On the basis of the unique nanostructure of CNANAs with large surface area(446.39 m² g^-1),hierarchical pores（centered at 2,12and 87 nm）and high density of edge-plane-like defective sites（EPDSs）,the CNANAs was used as an electrode material to modify the surface of the glassy carbon electrode（GCE）and constructed an electrochemical sensor（CNANAs/GCE）.Compared to carbon nanotubes（CNTs）modified GCE（CNTs/GCE）and GCE,the CNANAs modified GCE（CNANAs/GCE）showed higher electrocatalytic activities towards some elelctrochemical activity molecules,such as potassium ferricyanide,hydrogen peroxide（H₂O₂）,dopamine（DA）,ascorbic acid（AA）and uric acid（UA）.Compared to CNTs/GCE and GCE,the CNANAs/GCE exhibited a wider linear range（5–1760μM）,a higher sensitivity(42.4μA mM cm^-2)and a lower detection limit（3.53μM）for H₂O₂ detection.Especially,the CNANAs/GCE was used to detect the H₂O₂in human urine and serum samples by spiked recovery test.The calculated recovery was in the range of 99-102%,indicating that CNANAs/GCE has the ability to detect H₂O₂content in human body fluids.（2）The low-cost nitrogen-doped graphene-like mesoporous nanosheets（N-GMNs）were synthesized by using the biomass waste of okara and used to construct a nonenzymatic amperometric AA sensor.Compared to CNTs/GCE and GCE,N-GMNs-modified GCE（N-GMNs/GCE）for the electrooxidation of AA showed a lower overpotential,a wider linear range（10-5640μM）,a lower detection limit（0.51μM）,and a higher sensitivity(144.65μA mM cm^-2).Especially,the AA concentration in real samples（such as commercial beverage,commercial fruit drink and AA injection）could be determined by the proposed N-GMNs/GCE with satisfied results.Therefore,the utilization of okara as the raw material for the synthesis of nanostructured carbon of N-GMNs is a kind of green method to fabricate an advanced and low-cost electrode material for developing the nonenzymatic electrochemical sensor for AA detection.