One stone,three birds:up-conversion,photothermal and p-n heterojunction to boost BiOBr:Yb^(3+),Er^(3+)/Cu_(3)Mo_(2)O_(9) full spectrum photodegradation

Broadening spectral response range to realize the full spectrum photocatalysis is crucial to develop photocatalysts with satisfactory light-energy conversion ability.A full-spectrum driven p-n heterojunction photocatalytic system was rationally designed through introducing the Er^(3+)/Yb^(3+)co-doped BiOBr with up-conversion effect as the collector of near infrared light and photocatalysts substrate.Meanwhile,Cu_(3)Mo_(2)O_(9) with the photothermal effect as a heat source to accelerate the reaction at the surface through absorbing the near infrared light.The photocatalytic activity of BiOBr:Yb^(3+),Er^(3+)/Cu3Mo2O9 composite was markedly strengthened under visible and near infrared light irradiation,and the BiOBr:Yb^(3+),Er^(3+)/Cu_(3)Mo_(2)O_(9)-5 composite displayed the optimal photodegradation activities for 0.03372 min^(-1) and 0.058 h^(-1),being 2.3-folds and 2.4-folds than that of pure BiOBr:Yb^(3+),Er^(3+)under the visible and near infrared light,respectively.The position of doped ions(Yb^(3+)and Er^(3+))in BiOBr:Yb^(3+),Er^(3+)was determined from the X-ray absorption fine structure spectra.And the reasonable mechanism of p-n heterojunction was proposed base on the results of experimental and density functional theory calculation.This work provides a rational strategy for the design and development of full-spectrum heterojunction photocatalysts with the up-conversion and photothermal effects to increase the photocatalytic performance.

Self-Stabilized Precipitation Polymerization and Its Application

An efective,value-added use of the large amounts of olefnic compounds produced in the processing of petroleum,aside from ethylene and propylene,has been a long outstanding challenge.Here,we developed a novel heterogeneous polymerization method,beyond emulsion/dispersion/suspension,termed self-stabilized precipitation(2SP)polymerization,which involves the nucleation and growth of nanoparticles(NPs)of a well-defned size without the use of any stabilizers and multifunctional monomers(crosslinker).Tis technique leads to two revolutionary advances:(1)the generation of functional copolymer particles from single olefnic monomer or complex olefnic mixtures(including C4/C5/C9 fractions)in large quantities,which open a new way to transform huge amount of unused olefnic compounds in C4/C5/C9 fractions into valuable copolymers,and(2)the resultant polymeric NPs possess a self-limiting size and narrow size distribution,therefore being one of the most simple,efcient,and green strategies to produce uniform,size-tunable,and functional polymeric nanoparticles.More importantly,the separation of the NPs from the reaction medium is simple and the supernatant liquid can be reused;hence this new synthetic strategy has great potential for industrial production.