Fabrication of novel immobilized and forced Z-scheme Ag|AgNbO3/Ag/Er3+:YAlO3@Nb2O5 nanocomposite film photocatalyst for enhanced degradation of auramine O with synchronous evolution of pure hydrogen

An immobilized and forced Z-scheme Ag|AgNbO3/Ag/Er3+:YAlO3@Nb2O5 nanocomposite film photocatalyst is prepared via sol–gel spin coating and photoreduction technologies, and applied in solar photocatalytic removal of auramine O and synchronous evolution of pure hydrogen. An immobilized reactor with the nanocomposite film is designed to realize the photocatalytic oxidation and reduction on both sides of the Ag foil as carrier, respectively. The mechanism on the immobilized and forced Z-scheme Ag|AgNbO3/Ag/Er3+:YAlO3@Nb2O5 photocatalytic system is proposed. The results indicate that pure hydrogen can be directly produced on the surface of the Ag foil. The 318.37 μmol pure hydrogen can be collected at 84.90 mmol/h·m2, and 92.72 % degradation of 10 mg/L auramine O can be obtained under 180 min sunlight irradiation. Ag|AgNbO3/Ag/Er3+:YAlO3@Nb2O5 nanocomposite film also possesses high recycling capacity. This photocatalytic technology performs good application prospects in organic wastewater purification and hydrogen energy development.