Synthesis, structure and electrochemical properties of an inorganic–organic hybrid CuII[sbnd]CeIII heterometallic germanotungstate

Abstract

A new 1:2-type inorganic–organic hybrid CuIICeIII heterometallic germanotungstate (GT) derivative KNa2H9[enH2]2 [Cu(en)2(H2O)]2[Cu(en)2]2{Cu(en)2[Ce(α-GeW11O39)2]2}·14H2O (1) (en=ethylenediamine) was obtained by simultaneously introducing Cu2+ and Ce4+ cations to the trivacant Keggin-type [A-α-GeW9O34]10− system in the help of extra Na2WO4·2H2O and en ligand under hydrothermal conditions and was further characterized by elemental analyses, IR spectrum, thermogravimetric (TG) analysis and single-crystal X-ray diffraction. 1 exhibits a 1-D CuIICeIII heterometallic chain architecture by tetrameric {Cu(en)2[Ce(α-GeW11O39)2]2}24− units via K+ cations. Moreover, its solid-state electrochemical and electrocatalytic properties have been measured in 0.5molL−1 Na2SO4+H2SO4 aqueous solution by entrapping them in a carbon paste electrode, indicating that 1 displays apparent electrocatalytic activities for nitrite, bromate and hydrogen peroxide reduction.