Visible-light-activated N-doped CQDs/g-C3N4/Bi2WO6 nanocomposites with different component arrangements for the promoted degradation of hazardous vapors

To investigate whether the arrangement of componentsin multi-composite photocatalysts may affect their photocatalytic properties,due to different charge-transfer routes,two ternary-nanocomposite photocatalysts with different component arrangements,comprising N-doped carbon quantum dots(NCQDs),g-C3N4(CN),and Bi2WO6(BWO)(hereafter referred to as NCQDs/CN/BWO),were developed,and the photocatalytic degradation of model hazardous vapors under visible-light illumination was investigated.Type I NCQDs/CN/BWO,which was developed by the combination of NCQDs/BWO and CN,exhibited photocatalytic ability superior to that of type II NCQDs/CN/BWO,which was developed by the combination of CN/BWO and NCQDs;the superior photocatalytic ability corresponded to the dual properties of NCQDs:charge mediation and upconversion photoluminescence.Moreover,the photocatalytic ability of NCQDs/CN/BWO was greater than those of the reference catalysts;in addition,this photocatalyst exhibited outstanding photochemical stability.Additionally,the effects of CN/(BWO+CN)weight ratio of the CN/BWO dual nanocomposites and the NCQDs/(BWO+CN+NCQDs)weight percentage of NCQDs/CN/BWO ternary nanocomposites on the pollutant removal efficiency were investigated.The plausible mechanisms over the two NCQDs/CN/BWO photocatalysts for the degradation of hazardous vapors were discussed.The component arrangement approach proposed herein afforded a technique toward the perceptive development of novel multi-component heterostructures for the photocatalytic degradation of hazardous vapors.