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

Abstract

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 (·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 μmol 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.