Titania supported MOF-199 derived Cu-Cu2O nanoparticles: Highly efficient non-noble metal photocatalysts for hydrogen production from alcohol-water mixtures

Abstract

Fabrication of cheap and efficient photocatalysts is pivotal for practical applications of solar energy devices. Here, we illustrate a novel trend in generating Cu-Cu2O nanoparticles over TiO2 for water splitting systems. Titanium(IV) isopropoxide was hydrolysed in the presence of various wt% of MOF-199 ([Cu3(BTC)2(H2O)3]n) to obtain TiO2-MOF-199 composite materials. These composite materials are then calcined at various temperatures in air to produce highly dispersed Cu-Cu2O nanoparticles over TiO2; these nanoparticles were tested as photocatalyts for hydrogen generation from alcohol-water mixtures. The photocatalyst 1 wt% Cu/TiO2-400 was found to exhibit a hydrogen production rate some 2.5 times higher than that of CuO prepared by conventional precipitation methods. The calcination temperature of the TiO2-MOF composite was found to affect the oxidation state of Cu and the photocatalytic activity, with an optimum performance achieved at 400°C. Calcination beyond this temperature led to oxidation and agglomeration of Cu-Cu2O nanoparticles into larger CuO deposits, which reduce the H2 production activity (ca. 80%).