Cd-doped SnO2/CdS heterostructures for efficient application in photocatalytic reforming of glycerol to produce hydrogen under visible light irradiation

A series of mixed oxide (CdySn(1-y) O-2) were synthesized by Pechini method followed by ion exchange with sulfide ions and heat treatment in nitrogen atmosphere to reach Cd-doped SnO2 and binary (CdSnO2/ CdS) and ternary (Cd-SnO2/CdO/CdS and SnO2/CdO/CdS) composites. These materials have demonstrated able to absorb visible light and some of them are actives in photocatalytic reforming reaction of glycerol aqueous solution to produce hydrogen. The materials obtained in each step of the synthesis were characterized using different techniques (XRD, Raman, DRS, SEM and EDX). The influence of the calcination temperature in the ion exchange step, as well as the cadmium content in the formation of oxides and composites were investigated. A type II heterostructure, Cd(7%)-SnO2/(CdS)(0.3), was obtained when the start solution had the same amount of cadmium and tin and this composite has demonstrated the best photocatalytic activity in hydrogen production, around 290 mmol g(-1) h(-1). This value is very close to the obtained with commercial CdS, but with a great advantage, it has a lower content of cadmium, being less toxic. (C) 2017 Elsevier B.V. All rights reserved.