Activated-Carbon-Templated Crystalline Tantalates for Photocatalytic Water Splitting

Herein, we report a facile nanocasting route for the preparation of crystalline mesoporous Ta2O5 and NaTaO3 with a high surface area using activated carbon as the structure-directing hard template. The crystalline particles of Ta2O5 and NaTaO3 have mean sizes of 6 and 9 nm, constructing mesoporous networks with surface areas of 91 and 75 m(2)g(-1), respectively. The photocatalytic performances of the tantalum-based replicas were investigated for the water splitting reaction by using methanol as sacrificial agent and better photocatalytic performances were observed in comparison with bulk and amorphous counterparts. Loading the templated Ta2O5 and NaTaO3 with 1 wt% NiOx boosted their photocatalytic activity. The most-active sample, NaTaO3/ NiOx, was also tested for overall water splitting and it produced hydrogen and oxygen in stoichiometric ratios at rates of 129 and 66 mu molh(-1), respectively.