| As a kind of n-type semiconductor metal sulfide,Tin disulfide（Sn S2）has been widelystudied for a long time due to its unique advantages such as low toxicity,ease of preparation and good chemical stability.Various morphologies of Sn S2 nanomaterials,such as nanoflowers,nanosheets and nanorods,have been successfully prepared and empolyed in the fields of solar cells,photocatalysis,electrocatalysis,lithium ion batteries,sodium ion batteries and gas sensors.Due to its larger specific surface area and excellent biocompatibility,Sn S2 based nanomaterials also show great potential as electrode modification materials in electrochemical sensing.However,the conductivity of pure Sn S2 is poor,resulting in lower electrochemical activity.Researcheres found that the electrochemical properties of metal sulfide could be greatly improved by doping metal atoms,combining with carbon-based nanomaterials and designing special nanostructure.Therefore,this paper explored three modification strategies of Sn S2 and approached the application value of tin-based sulfides in electrochemical sensors.Three sensing platforms were constructed for the sensitive detection of paracetamol,ascorbic acid and nitrite.The specific research work is as follows:1.In our research,the transition metal element Fe alone,Fe and Co in coordination,and rare metal element In alone were successfully doped with Sn S2 by simple hydrothermal method to obtain Fe-Sn S2,Fe Co-Sn S2,and In-Sn S2 nanocomposites.After the exploration of experimental conditions,when the total amount of metal doping is 5%,the obtained Sn S2nanosheet has uniform and minimum microstructure.These nanocomposites were further used to modify glassy carbon electrode and construct a sensing platform for the oxidation of acetaminophen.The results show that bimetallic Fe and Co co-doped Sn S2 nanosheets have the best electrochemical sensing performance,which is due to the bimetallic synergistic effect.Through electrochemical test,the oxidation current of paracetamol catalyzed by Fe Co-Sn S2 nanosheets is proportional to its concentration,so the detection of paracetamol can be realized.The electrochemical sensor based on Fe Co-Sn S2 nanosheets exhibit excellent sensing properties for the oxidation of acetaminophen,such as wide linear range（1-1320μM）,low detection limit（0.14μM）,good selectivity and long-term stability.Finally,the modified electrode was applied to the determination of acetaminophen sustained-release tablets,a practical sample containing acetaminophen,and satisfactory results were obtained.2.In this paper,three biomass carbon nanomaterials were synthesized at first through activation and carbonization by using black fungus,orange peel and walnut shell as carbon sources,and then the three biomass carbons were compounded with Sn S2 via one-step hydrothermal method.The SEM characterization technology showed that the three Sn S2 based nanocomposites retained the flake structure of pure Sn S2.However,thinner nanosheets than pure Sn S2 were obtained,so they had larger specific surface area,improved electrical conductivity,accelerated electron transport,and thus improved their electrochemical sensing activity.Finally,we achieved the electrochemical detection of ascorbic acid based on the Sn S2nanosheets of agaric biomass carbon composite.The linear range of the sensor is 10-8000μM,and the detection limit is as low as 0.027μM（S/N=3）.3.Hollow micron cubic Zn Sn（OH）6 was prepared by self-template co-precipitation method and alkali etching method.Furthermore,the complexing agent EDTA was introduced to extract Zn2+under hydrothermal conditions,and the sulfurization reaction was conducted at the same time to prepare Sn S2 microncubes.The Sn S2 cubic surface is nanosheet structure with high specific surface area and more surface active sites,which can obtain better catalytic activity.Further characterization proves that this hierarchical structure has excellent electronic transmission capability.The Sn S2 microcube hierarchical structure was modified on glassy carbon electrode to construct an electrochemical sensor for nitrite.Sn S2 showed excellent catalytic oxidation activity for nitrite,and the increase of oxidation current was proportional to the concentration of nitrite,thus realizing the quantitative detection of nitrite.The electrochemical sensor show excellent catalytic oxidation activity for nitrite,with a good linear relationship in the range of 10-5040μM and with a detection limit of 0.16μM. |
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