Preparation Of Bi₂S₃based Composites And Their Application In Photoelectrochemical Sensing

Photoelectrochemical sensing technology,as an analysis and detection technology emerging in recent years,has the advantages of simple equipment,low cost,and fast detection.It uses light as excitation source.After a semiconductor material is irradiated with light,it absorbs photons and generate photo-current signal.When it is combined with a recognition element to construct sensor,the interaction between the target and the recognition element will cause electrical signal change,which can be used for the detection of target analyte.In this study,the narrow-bandgap semiconductor material bismuth sulfide is used as a photoelectric material.It is combined with other materials to improve its photoelectric performance,and then combined with molecularly imprinted polymers with molecular recognition functions to build sensors and use them in environmental water samples and food.Wait for the measurement of the sample.The specific research content and results are as follows.1.A type I Bi₂S₃@Zn S core–shell structured photocatalyst for the selective photoelectrochemical sensing of Cu²⁺A type I core/shell structured Bi₂S₃@Zn S photocatalyst was synthesized by an electrostatic interaction mechanism and used for the photoelectrochemical detection of Cu²⁺.The Bi₂S₃@Zn S composite showed excellent photoelectrochemical activity and stability due to the high photoelectrochemical activity of Bi₂S₃ and the anti-photocorrosion function of the Zn S shell.In addition,the Zn S shell also provided a transfer platform for the photogenerated holes through its acceptor states(i.e.V_Zn and I_S)and suppressed the recombination of photogenerated carriers.The photocurrent signal of the obtained Bi₂S₃@Zn S/ITO electrode was much higher than that of pure Bi₂S₃ under visible-light irradiation.When it was used for the photoelectrochemical sensing of Cu²⁺,a wide detection range（0.003–30.0 m M）and a low detection limit（0.001 m M）were observed.The sensor also displayed high stability and acceptable selectivity.It was applied to detect real samples and good results were achieved.2.Novel molecularly imprinted photoelectrochemical sensor for rutin based on Bi₂S₃/Zn In₂S₄heterojunction.An MIP/Bi₂S₃/Zn In₂S₄/ITO sensor was fabricated and used for the photoelectrochemical detection of rutin.The Bi₂S₃/Zn In₂S₄ composite was synthesized by solvothermal method and it owned pretty good photoelectrochemical property because of the matched energy level of Bi₂S₃ and Zn In₂S₄.In addition,Zn In₂S₄ also enhanced the stability of the composite material and avoided photocorrosion.The photocurrent signal of the obtained Bi₂S₃/Zn In₂S₄ composite was much lager than that of sole Bi₂S₃ and Zn In₂S₄ under visible-light irradiation.The template rutin was imprinted into chitosan skeleton by hydrogen-bond interaction,followed by simple cross-linking reaction with glutaraldehyde at room temperature.The molecularly imprinted material was combined with Bi₂S₃/Zn In₂S₄/ITO,and the resulting photoelectrochemical sensor showed a low detection limit（0.003μM）and a wide detection range（0.01-100.0μM）for rutin.It also displayed high stability and selectivity.It was sucessfully applied for the detection of rutin in real samples.