Synthesis And Improved Photocatalytic Performances Of One-dimensional High-quality Interface Bismuth Oxide Heterojunction

Rapidly growing industries and the rising global population in recent years are key factors that cause energy shortages and environmental pollution.Therefore,in order to ensure the long-term and sustainable development of human society,there is an urgent need to develop environmentally friendly and renewable technologies for green energy production and environmental remediation.Among various proposed technologies,photocatalytic technology is considered as one of the most promising technologies for eliminating organic contaminations from aqueous solutions.Heterojunctions can facilitate the effective separation of electrons and holes.They can perfectly combine the functions of different semiconductors,broaden the absorption range of light,and further improve the performance of the catalyst.However,in practical applications,the catalytic activity is deactivated after the heterojunction is used several times.The reason is that the quality of the interface is too low.Therefore,this paper mainly studies the synthesis of High-quality Interface Bismuth oxide Heterojunction.The specific contents is presented below:1.Via calcining the Bi?OHC₂O₄?·2H₂O-Bi₂VO_5.5 precursor in air at 350oC for 3 h,the target product of 1 D high-qulity interface Bi₂O₃-Bi₄V₂O₁₁ was obtained.Bi₄V₂O₁₁ is epitaxially grown on Bi₂O₃ porous rods,which not only improves the quality of the interface,but also provides the minimum penetrative barrier for the transfer of electron-hole pairs between Bi₂O₃-Bi₄V₂O₁₁ interfaces.The obtained Bi₂O₃-Bi₄V₂O₁₁heterojunction is superior to pure Bi₂O₃ and Bi₄V₂O₁₁ for degradation of high concentrations of phenol?and MO?under visible light irradiation.Using Bi₂O₃-Bi₄V₂O₁₁?DS-2?heterostructure as photocatalyst,40 mg/L phenol can be completely degraded in 30min under the irradiation of visible light.The reason for the enhanced photocatalytic activity is the synergistic effect of suitable band alignmentof Bi₂O₃ and Bi₄V₂O₁₁,high interface quality,and one-dimensionally ordered nanostructures.The results of the free radical trapping experiments show that?h⁺?and·O₂^-are the main active substances for the degradation of phenol?and MO?in the photocatalytic process.This work will provide a simple and effective strategy for the design and manufacture of heterojunction photocatalysts with high quality interfaces.2.In the first place,Bi?OHC₂O₄?·2H₂O was selected as the precursor to synthesize Bi?OHC₂O₄?·2H₂O-BiOI through hydrothermal method.The Bi?OHC₂O₄?·2H₂O-BiOI precursor was calcined in air at 350oC for 3 h to prepare 1 D high-quality interface Bi₂O₃-Bi₅O₇I composite.Bi₅O₇I nanosheets were epitaxially grown on Bi₂O₃ porous rods,which improve the interface quality and provide a minimal penetrative barrier for the transfer of electron-hole pairs between Bi₂O₃-Bi₅O₇I interfaces.The photocatalytic performance of the product was measured by means of degrading MO?and phenol?under visible light irradiation.The experimental results show that the photocatalytic activity of Bi₂O₃-Bi₅O₇I heterostructure is higher than that of pure Bi₂O₃ and Bi₅O₇I.Bi₂O₃-Bi₅O₇I?DS-2?heterojunction can completely degrade 30 mg/L MO in 60 min under visible light irradiation.The capture experiments show that the holes?h⁺?and superoxide radicals?·O₂^-?are the main active substances for the degradation of MO?and phenol?in the photocatalytic process.This work will provide a simple and effective strategy for the design and manufacture of heterojunction photocatalysts with high quality interfaces.3.One-dimensional Bi₂O₃-Bi₂O₂CO₃ heterostructures with enhanced photocatalytic properties of sunlight were synthesized by high-temperature calcination of Bi₂O₂CO₃precursors.The morphology of the Bi₂O₃-Bi₂O₂CO₃ heterostructure is a one-dimensional rod-like structure composed of many nanoplatelets.The catalytic degradation experiments show that Bi₂O₃-Bi₂O₂CO₃ heterojunction is superior to pure Bi₂O₃ and Bi₂O₂CO₃ in the degradation of MO and phenol under sunlight irradiation.Under sunlight irradiation,10mg/L methyl orange?MO?and 20 mg/L phenol can be completely degraded within 15 min and 50 min,respectively.The increase in photocatalytic activity is due to the interaction between the interface of Bi₂O₂CO₃ and Bi₂O₃ and the effective transfer and separation of charge carriers.The capture experiments show that the holes?h⁺?and superoxide radicals?·O₂^-?are the main active substances for the degradation of MO?and phenol?in the photocatalytic process.This work provides a simple and effective strategy for the preparation of heterojunctions with high catalytic activity.