Hexamolybdenum Clusters Supported on Graphene Oxide: Visible-Light Induced Photocatalytic Reduction of Carbon Dioxide into Methanol

Pawan Kumar (1) , Harshal P. Mungse (1) , Stéphane Cordier (2) , Rabah Boukherroub (3) , Om P. Khatri (1) , Suman L Jain (1)

1 CSD - Chemical Sciences Division [Dehradun]
2 ISCR - Institut des Sciences Chimiques de Rennes
3 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520

Hexamolybdenum (Mo6) cluster-based compounds namely Cs2Mo6Bri8Bra6 and (TBA)2Mo6Bri8Bra6 (TBA = tetrabutylammonium) were immobilized on graphene oxide (GO) nanosheets by taking advantage of the high lability of the apical bromide ions with oxygen-functionalities of GO nanosheets. The loading of Mo6 clusters on GO nanosheets was probed by Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and elemental mapping analyses. The developed GO-Cs2Mo6Bri8Brax and GO-(TBA)2Mo6Bri8Brax composites were then used as heterogeneous photocatalysts for the reduction of CO2 under visible light irradiation. After 24 h visible light illumination, the yield of methanol was found to be 1644 and 1294 μmol.g-1cat for GO-Cs2Mo6Bri8Brax and GO-(TBA)2Mo6Bri8Brax, respectively. The quantum yields of methanol by using GO-Cs2Mo6Bri8Brax and GO-(TBA)2Mo6Bri8Brax as catalysts with reference to Mo6 cluster units presented in 0.1g amount of catalyst were found to be 0.015 and 0.011, respectively. The role of immobilized Mo6 clusters-based compounds on GO nanosheets is discussed to understand the photocatalytic mechanism of CO2 reduction into methanol

Mots clés: Graphene oxide; Carbon dioxide reduction; Mo cluster compound; photocatalysis; Methanol

Domaines: Chimie; Matériaux

Pawan Kumar, Harshal P. Mungse, Stéphane Cordier, Rabah Boukherroub, Om P. Khatri, et al.. Hexamolybdenum Clusters Supported on Graphene Oxide: Visible-Light Induced Photocatalytic Reduction of Carbon Dioxide into Methanol. Carbon, 2015, 94, pp.91-100. ⟨10.1016/j.carbon.2015.06.029⟩. ⟨hal-01166772⟩