| CsPbBr3 perovskite is a p-type semiconductor material with low synthesis cost and simple synthesis method.Compared with traditional semiconductor materials,perovskite with excellent optical and electrical properties is the best photoactive material,and it has great application potential in the fields of photoelectrochemical biosensing and photocatalysis.Due to the low formation energy and inherent ionic crystal properties of CsPbBr3 perovskite,it has extremely high sensitivity to moisture,ultraviolet rays,heat and oxygen,which limits its practical application in photoelectrochemical biosensing.The photoelectrochemical stability of perovskite needs to be solved urgently.NiO is a p-type semiconductor with large band gap（3.6-4.0 eV）,which is rich in resources,environmentally friendly and low in manufacturing cost,it mainly absorbs ultraviolet light in the spectral range.NiO can improve the charge carrier transfer efficiency of CsPb Br3,due to its suitable band gap,has become a research hotspot in perovskite solar cells.Three-dimensional nanoporous structure of NiO has a large specific surface area,which is beneficial to the large amount of photosensitizer loading and improves the photoelectrochemical stability of the photosensitizer in aqueous solution.Firstly,one high-efficiency photocathode based on surface ligand carbonized CsPbBr3 quantum dots（QDs）and NiO was constructed,using dissolved oxygen as an electron acceptor.Under simulated sunlight,the hybrid photocathode showed a sensitive photocurrent response at a 0 V bias potential.Due to the heat treatment at 300℃in the inert atmosphere,a hydrophobic carbon film was formed on the surface of CsPbBr3.By heat treatment at 300℃in an inert atmosphere,a hydrophobic carbon film was formed on the surface of CsPbBr3.Compared with heat-treated electrodes at 100℃,200℃and 400℃,the photocathode showed a stable photoelectric response for 7 min in the aqueous electrolyte solution at300℃.Through XPS characterization and carbonization verification experiments,it can be determined that the carbon ligand of CsPbBr3surface carbonized at 300℃,and the photoelectrochemical stability of the composite electrode was improved.Secondly,the glucose oxidase was successfully modified on the C/CsPbBr3/NiO/ITO electrode through the cross-linking of EDC and NHS,and photoelectrochemical glucose sensing was performed.These findings are expected to provide a certain reference value for the research of all-inorganic perovskites in the field of photoelectrochemical biosensing.Finally,the photoelectrochemical properties of C/CsPbBrx I3-x/NiO/ITO（x=2.5,2,1.5,0）electrodes with different iodine doping concentrations in water were compared.As the iodine doping concentration increases,the photocurrent intensity of the electrode increases.The composition and photoelectrochemical stability of C/CsPbBr1.5I1.5/NiO/ITO electrode were investigated by XRD,XPS and PEC characterization. |
