Enhanced visible-light photocatalytic hydrogen evolution activity of Er3+:Y3Al5O12/PdS–ZnS by conduction band co-catalysts (MoO2, MoS2 and MoSe2)

Several conduction band co-catalysts (CBCOs), MoO 2 , MoS 2 and MoSe 2 , were prepared to improve the visible-light photocatalytic hydrogen evolution activity of Er 3+ :Y 3 Al 5 O 12 /PdS–ZnS from water splitting, in which the PdS is a valence band co-catalyst (VBCO) used to facilitate the photo-generated hole transfer and the Er 3+ :Y 3 Al 5 O 12 is an up-conversion luminescence agent from visible light to ultraviolet light used to provide the ultraviolet light satisfying the energy demands of wide band-gap ZnS photocatalyst . XRD , SEM, TEM and EDX analyses were employed to confirm the morphology, microstructure and composition of the prepared photocatalysts. UV–vis absorption and PL spectra were also determined to explore luminescence effect of the Er 3+ :Y 3 Al 5 O 12 . The visible-light photocatalytic hydrogen evolution activity of the prepared photocatalysts was evaluated by using Na 2 S and Na 2 SO 3 as sacrificial reagents in aqueous solution under visible light irradiation . The influential factors such as contents of CBCOs (MoO 2 , MoS 2 and MoSe 2 ) and visible-light irradiation time on visible-light photocatalytic hydrogen evolution of Er 3+ :Y 3 Al 5 O 12 /PdS–ZnS–MoX 2 (X = O, S and Se) were investigated in detail. Particularly, Er 3+ :Y 3 Al 5 O 12 /PdS–ZnS–MoSe 2 with 0.30 wt% MoSe 2 shows the highest photocatalytic hydrogen evolution activity.