| Antibiotics discharging from agriculture and animal husbandry entered into water and caused serious pollution.Reuse of reclaimed water is the recovery and treatment of polluted water sources,which is used to irrigate farmland and can effectively alleviate the shortage of water resources for farmland irrigation.As an advanced oxidation technology,photocatalysis technology can effectively eliminate antibiotic pollution with a low cost.Black phosphorus(BP)has attracted more and more attention as a photocatalyst because of its anisotropy,high carrier mobility and adjustable band gap.Therefore,using BP nanosheets as photocatalysts for antibiotic degradation has good application prospects.However,the instability and high carrier recombination rate of BP limit its application in the degradation of antibiotics.How to construct a stable functionalized BP nanosheet and form a good interface with other semiconductors is a crucial issue.In this paper,tetracycline hydrochloride and ciprofloxacin are used as target pollutants.The interface interaction and coupled effect bewteen BP and other semiconductors have been studied.The environmental fate of the photodegradation of antibiotics was evaluated and the mechanism of photocatalysis also was summarized.The main findings are as follows:(1)PDDA functionalized BP nanosheets can improve the stability of BP and change its surface properties,then a Z-scheme heterostructure with Bi OI was constructed.Through the construction of Z-scheme,functionalized BP and Bi OI formed a favorable interface effect.After excitation,the electrons generated on the Bi OI valence band migrated to the conduction band,and then transferred to the valence band of BP to combine with holes.Holes on Bi OI and electrons on BP were spatially separated,which effectively improved the separation efficiency of photogenerated carriers.Bi OI enhanced light absorption capacity by combining with functionalized BP.The Bi OI and BP composite photocatalytic material showed good removal efficiency for tetracycline hydrochloride under visible light,and the removal rate of the composite sample reached90% when the BP addition amount was 5 m L.(2)A heterogeneous structure was constructed using two-dimensional functionalized BP nanosheets and CdS of different dimensions.The results showed that the 2D-2D composite structure of 2D BP nanosheets and 2D CdS showed the best degradation efficiency for both tetracycline hydrochloride and ciprofloxacin.Compared with the 2D-1D and 2D-3D composite catalytic structure,the 2D-2D heterostructure forms face-to-face contact,resulting in larger contact interface and stronger electrostatic coupling,which promotes the rapid interface crossing of electrons through the surface tunneling effect.As a result,the photogenerated electrons and holes can separated efficiency.At the same time,the doping amount of BP also had a certain effect on the composite catalytic material.When the addition amount of black phosphorus nanosheets in 2D CdS was adjusted to 5 m L,the degradation rates of tetracycline hydrochloride and ciprofloxacin reached to 91.5% and 92.7%,respectively.(3)One of the difficulties in putting the photocatalyst into practical use was the recovery of the catalyst.In response to this issue,this study constructed a macroscopic three dimensional graphene-black phosphorus-cadmium sulfide foam structure.The three-dimensional structure showed a good synergy of catalysis and adsorption,and the introduction of graphene and BP improved carrier mobility.After five times cycle test,the results showed that the structure of composite material maintained good stability.The stable structure can effectively solve the problem of material recycling.The method provids a way for the practical application of photocatalytic materials. |
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