Soft template inducted hydrothermal BiYO3 catalysts for enhanced formic acid formation from the photocatalytic reduction of carbon dioxide

Bismuth yttrium oxide (BiYO3) photocatalysts were hydrothermally prepared using sodium dodecyl benzene sulfonate (SDBS), disodium ethylenediamine tetraacetate (EDTA), and citric acid (CA) as soft templates. The effects of templates on the formed BiYO3 nanostructures were revealed. The BiYO3 nanostructures prepared without the existing template and with the existence of SDBS, EDTA, and CA as templates had flaked structures, sliced, rectangular lath structures with fine particles, and scaly uniform particles, respectively. The photocatalytic reduction of CO2 under visible-light irradiation with these synthesized BiYO3 nanostructures was studied and compared. Due to the larger specific surface area, higher adsorbed edge, and lower band gap, BiYO3 prepared using EDTA as a template produced fewer hydroxyl free radicals (center dot OH) to give a higher yield of formic acid (HCOOH) in the process of the photocatalytic reduction of CO2. The HCOOH yield from the photocatalytic reduction of CO2 by the EDTA synthesized BiYO3 was 1.68 mu mol L-1, which was 1.9 times higher than that produced from BiYO3 prepared without a template, and 2.6 times higher than that of BiYO3 prepared by a solid-state reaction.