Efficient photocatalytic hydrogen evolution from methanol/water splitting over Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12/MoS2–NaTaO3 nanocomposite particles under infrared–visible light irradiation

Abstract

In this paper, two efficient up-conversion luminescence agents, Tm3+,Yb3+:NaYF4 (from infrared light to ultravoilet light) and Er3+:Y3Al5O12 (from visible light to ultravoilet light), were synthesized by hydrothermal and sol–gel methods, respectively. And then, a novel photocatalyst, Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12/MoS2–NaTaO3 nanocomposite particles, were successfully prepared by hydrothermal and calcination methods for infrared–visible light photocatalytic hydrogen evolution. For comparison and confirmation, Tm3+,Yb3+:NaYF4, Er3+:Y3Al5O12, MoS2–NaTaO3, Tm3+,Yb3+:NaYF4/MoS2–NaTaO3, Er3+:Y3Al5O12/MoS2–NaTaO3, and Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12/MoS2–NaTaO3 were all characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The photocatalytic activity of Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12/MoS2–NaTaO3 nanocomposite particles was examined through photocatalytic hydrogen evolution from methanol splitting under infrared–visible light irradiation. The influence factors such as mass ratio of Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12 and NaTaO3, calcination temperature, solution acidity (pH) and used time on the infrared–visible light photocatalytic hydrogen evolution activity of Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12/MoS2–NaTaO3 nanocomposite particles were studied. Particularly, the prepared Tm3+,Yb3+:NaYF4–Er3+:Y3Al5O12/MoS2–NaTaO3 nanocomposite particles with the mass ratio of 0.3:1.0 heat-treated at 500°C for 120min in pH=6.0 solution with 10.0wt % methanol displayed a high infrared–visible light photocatalytic activity in hydrogen production from water solution.