Colloidal zinc oxide-copper(I) oxide nanocatalysts for selective aqueous photocatalytic carbon dioxide conversion into methane

Abstract

Developing catalytic systems with high efficiency and selectivity is a fundamental issue for photochemical carbon dioxide conversion. In particular, rigorous control of the structure and morphology of photocatalysts is decisive for catalytic performance. Here, we report the synthesis of zinc oxide-copper(I) oxide hybrid nanoparticles as colloidal forms bearing copper(I) oxide nanocubes bound to zinc oxide spherical cores. The zinc oxide-copper(I) oxide nanoparticles behave as photocatalysts for the direct conversion of carbon dioxide to methane in an aqueous medium, under ambient pressure and temperature. The catalysts produce methane with an activity of 1080 μmol gcat −1 h−1, a quantum yield of 1.5% and a selectivity for methane of >99%. The catalytic ability of the zinc oxide-copper(I) oxide hybrid catalyst is attributed to excellent band alignment of the zinc-oxide and copper(I) oxide domains, few surface defects which reduce defect-induced charge recombination and enhance electron transfer to the reagents, and a high-surface area colloidal morphology.

Mechanisms of catalytic reduction of CO2 with heme and nonheme metal complexes

“…There are many reports on the photocatalytic reduction of CO 2 with water as an electron and proton source to produce CO, HCOOH and CH 4 using heterogenous catalysts. 174 – 184 It is highly desired to develop photocatalytic systems of CO 2 reduction to fuels such as ethylene, methanol and methane using water as an electron and proton source using homogeneous molecular catalysts as well.…”

Progress through synergistic effects of heterojunction in nanocatalysts ‐ Review

“…[28] Introducing the reactive sites and pores into nanocomposites is thus an essential prerequisite to obtain active catalysts. The recent rapid progress in nanoscience enables the integration of these unique textures into the heterostructured catalysts at atomic and molecular scales by exploiting new fabrication routes to the structural diversity of new nanostructures such as hybrid colloids, [29] core-shells, [30] porous layered thin films, [31] etc. These approaches present many advantages over conventional techniques to result in affording innovative catalysts with advanced reaction performance.…”

Materials for CO2, SOx, and NOx Emission Reduction

“…The zinc oxide-copper(I) oxide nanoparticles behave as photocatalysts for the direct conversion of carbon dioxide to methane in an aqueous medium, under ambient pressure and temperature [44]. A highly efficient homogeneous catalyst system for the production of CH 3 OH from CO 2 has been developed [45].…”