Charge partitioning by intertwined metal-oxide nano-architectural networks for the photocatalytic dry reforming of methane

The photocatalytic dry reforming of methane (photoDRM: CH4 + CO2 = 2CO + 2H2) converts greenhouse gases into valuable synthesis gas with photon energy. However, previous photoDRM catalysts comprising supported metal nanoparticles hardly avoid the recombination of photoexcited charges. Herein, we report that significant photoDRM performance can be achieved by a metal-oxide nanocomposite consisting of nanometer-thick, intertwined networks of fibrous rhodium metal and cerium dioxide, i.e., Rh#CeO2. The Rh#CeO2 nanocomposite exhibits the world-highest conversion and yield in photoDRM under UV light irradiation, being accompanied with no other side reactions such as reverse water gas shift reaction. Theoretical simulations and Kelvin probe force microscopy demonstrate that the photoexcited electrons and holes in Rh#CeO2 are efficiently partitioned into the Rh- and CeO2 nanophases, respectively. The efficient charge partitioning in Rh#CeO2 accounts for the selective photoDRM reaction.