Efficient visible-light photocatalytic hydrogen evolution over platinum supported titanium dioxide nanocomposites coating up-conversion luminescence agent (Er~(3+):Y_3Al_5O_(12)/Pt-TiO_2)

摘要

In this work, a novel up-conversion luminescence agent (Er~(3+):Y_3Al_5O_(12)) was synthesized by sol-gel method and then for visible-light photocatalytic hydrogen evolution a corresponding visible-light photocatalyst, platinum supported titanium dioxide nanocomposites coating up-conversion luminescence agent (Er~(3+):Y_3Al_5O_(12)/Pt-TiO_2 nanocomposite particles), was successfully prepared by sol-gel and calcination methods. Er~(3+):Y_3Al_5O_(12) Pt-TiO_2 and Er~(3+):Y_3Al_5O_(12)/Pt-TiO_2 were all characterized by X-ray diffrac-tometer (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectroscopy (EDX). The visible-light photocatalytic activity of Er~(3+):Y_3Al_5O_(12)/Pt-TiO_2 nanocomposites was examined through photocatalytic hydrogen evolution from methanol splitting under visible-light irradiation. The influence factors such as Er~(3+):Y_3Al_5O_(12) and Pt-TiO_2 mole ratio, heat-treated temperature and heat-treated time on the visible-light photocatalytic hydrogen evolution activity of Er~(3+):Y_3Al_5O_(12)/Pt-TiO_2 nanocomposites were also studied. Particularly, Er~(3+):Y_3Al_5O_(12)/Pt -TiO_2 nanocomposites with 1.5:1.0 M ratio heat-treated at 500 ℃ for 60 min showed the highest visible-light photocatalytic activity in hydrogen evolution from methanol splitting.