Fabrication of loaded Ag sensitized round-the-clock highly active Z-scheme BiFeO3/Ag/Sr2MgSi2O7:Eu2+,Dy3+/Ag photocatalyst for metronidazole degradation and hydrogen production

To achieve efficient round-the-clock photocatalytic degradation of organic pollutants with simultaneous hydrogen production, Sr2MgSi2O7:Eu2+,Dy3+ with long-afterglow luminescence property and photocatalytic activity was selected to combine with BiFeO3 to construct a novel Z-scheme photocatalytic system. The luminescence intensity of Sr2MgSi2O7:Eu2+,Dy3+ and round-the-clock photocatalytic activity of the Z-scheme BiFeO3/ Ag/Sr2MgSi2O7:Eu2+,Dy3+/Ag photocatalyst were enhanced by loading Ag nanoparticles. In the presence of BiFeO3/Ag/Sr2MgSi2O7:Eu2+,Dy3+/Ag photocatalyst, the metronidazole degradation rate and hydrogen production amount were 63.85% and 444.64 & mu;mol/g, respectively, under sunlight irradiation for 240 min, which were approximately 3.39 and 3.63 times as high as ones of BiFeO3 and Sr2MgSi2O7:Eu2+,Dy3+. When the external light was removed for 240 min, the metronidazole degradation rate and hydrogen production amount increased by 9.08% and 57.07 & mu;mol/g, which were 4.12 and 3.15 times as high as ones of BiFeO3 and Sr2MgSi2O7:Eu2+, Dy3+ photocatalysts. This work provides a new research orientation for the design of a highly active Z-scheme photocatalyst for round-the-clock photocatalytic organic pollutants degradation with simultaneous hydrogen production.