Metal-doped polyoxometalates with dual-ligand for efficient CO2 photoreduction

Abstract

The design of highly active photocatalysts for carbon dioxide reduction is of far-reaching significance for the mitigation of industrial exhaust pollution and sustainable development. In this work, three catalysts containing dual ligands and doped metal V, [Co(DAPSC)(H2O)2]2[Co(H2O)5]0.5[PW11CoO39(Hdatrz)]‧3.5H2O (1), (H2bim)[ Co(DAPSC)(bim)( H3PW10VIV2O40)]‧4H2O (2), and [Co(DAPSC)(bbi)(H2O)]2(PW11.5VIV0.5O40)‧4H2O (3) [DAPSC = 2,6-diacetylpyridine bis-(semicarbazone), Hdatrz = 3,5-diamino-1,2,4-triazole, bim = bis(1-imidazolyl)methane, bbi = 1,1’-(1,4-butanediyl)bis(imidazole)], have been successfully synthesized under hydrothermal condition. A systematic exploration was undertaken to characterise the structures and photocatalytic transformations. Among that the results of both the IR and EDS tests demonstrated the successful doping of V atoms. The photocatalytic CO2 reduction exploration demonstrated that all catalysts modified with dual ligands exhibited high photocatalytic activity. The results therein demonstrated that catalyst 2 exhibited the most efficient photocatalytic performance in the reduction of carbon dioxide using visible light. Under optimal conditions, the CO yield reached 11003.3 μmol g-1 h-1 and maintained good catalytic activity after five cycles, outperforming the majority of the reported heterogeneous POM-based photocatalysts. The present study proves that the additional doping of transition metal vanadium in catalysts based on dual ligands downstream contributes to the development of highly active photocatalysts for CO2 reduction.