Modifying surface frustrated Lewis pairs of BiOBr by La3+ replacing Bi3+ for expediting CO2 photoreduction

Abstract

Photocatalytic reduction of carbon dioxide has attracted remarkable attention. However, the photocatalytic efficiency is restricted to the poor capacity of adsorption and activation for CO2 molecules on the surface of catalyst. Herein, La isomorphous substituted BiOBr is prepared by a convenient chemical method with La3+ replacing Bi3+. For CO2 photoreduction, the La-substituted BiOBr shows CO yield of 154.4 μmol·g−1·h−1, being 7.1-fold as higher as original BiOBr. Experimental and calculation results manifest that surface frustrated Lewis acid and base sites of La3+-O2− pairs are formed on the surface of BiOBr with adulteration of La and increased oxygen vacancies, which could be conductive to the adsorption and activation for CO2 molecules. This work not only suggests a possible mechanism for photocatalytic reduction of CO2, but also opens up a new opportunity for the preparation of efficient catalysts for CO2 reduction.