A new visible-light driving nanocomposite photocatalyst Er3+:Y3Al5O12/MoS2–NaTaO3–PdS for photocatalytic degradation of a refractory pollutant with potentially simultaneous hydrogen evolution

Abstract

A new visible-light-sensitive photocatalyst, Er³⁺:Y₃Al₅O₁₂/MoS₂–NaTaO₃–PdS, was prepared by hydrothermal, liquid boiling and deposition methods. The prepared photocatalysts were all characterized using an X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The photocatalytic activity of the prepared photocatalysts was evaluated via photocatalytic degradation of amaranth as a refractory pollutant with simultaneous hydrogen evolution under visible-light irradiation. Moreover, the effects of the visible-light irradiation time and molar ratio of Er³⁺:Y₃Al₅O₁₂ and NaTaO₃ on the photocatalytic capability of Er³⁺:Y₃Al₅O₁₂/MoS₂–NaTaO₃–PdS were studied. The results show that the use of Er³⁺:Y₃Al₅O₁₂ can improve the utilization ratio of visible light (solar light) for NaTaO₃. The optimum ratio of Er³⁺:Y₃Al₅O₁₂ and NaTaO₃ is 0.45 : 1.00. In addition, a study of extended reusability shows that the prepared photocatalyst can be effectively recycled for three repetitive cycles without an apparent deactivation of the photocatalytic activity. A visible-light photocatalytic degradation mechanism of amaranth with simultaneous hydrogen evolution is also proposed.