Photoelectrochemical sensor based on Bi2S3 @g-C3N4 heterojunction for the detection of chlorpyrifos

In this study, a simple wet chemical method was used to prepare p-n heterojunction photoelectric composites (Bi2S3@g-C3N4). The p-n junctions were formed to facilitate charge transfer as well as strongly suppress electron-hole pair recombination, thus enhancing the photoelectrochemical (PEC) characteristics. Particularly, according to the transient surface photocurrent response, the photocurrent intensity of the prepared composites was 2.98 times higher relative to the pristine g-C3N4 material. The photocurrent signal revealed the prepared novel PEC sensor composed of Bi2S3@g-C3N4 composite material, which can be used for sensitively and selectively detecting chlorpyrifos. This method presented a linear change from 50 ng/mL to 0.1 mg/mL of chlorpyrifos under the optimal conditions. The linear regression equation was I(μA)=0.8546-0.1558lgC(mg/mL) (R2=0.9758) and the detection limit was 0.03 ng/mL (S/N=3). In addition, the novel sensing platform with high selectivity could assist in rapidly and effectively detecting chlorpyrifos in environmental analysis.