Abstract
Cerium-rich metal oxide materials have recently emerged as promising candidates for the photocatalytic oxygen evolution reaction (OER). In this article, we report the synthesis of ordered mesoporous CuO/CeO2 composite frameworks with different contents of copper(II) oxide and demonstrate their activity for photocatalytic O2 production via UV-Vis light-driven oxidation of water. Mesoporous CuO/CeO2 materials have been successfully prepared by a nanocasting route, using mesoporous silica as a rigid template. X-ray diffraction, electron transmission microscopy and N2 porosimetry characterization of the as-prepared products reveal a mesoporous structure composed of parallel arranged nanorods, with a large surface area and a narrow pore size distribution. The molecular structure and optical properties of the composite materials were investigated with Raman and UV-Vis/NIR diffuse reflectance spectroscopy. Catalytic results indicated that incorporation of CuO clusters in the CeO2 lattice improved the photochemical properties. As a result, the CuO/CeO2 composite catalyst containing ~38 wt % CuO reaches a high O2 evolution rate of ~19.6 µmol·h−1 (or 392 µmol·h−1·g−1) with an apparent quantum efficiency of 17.6% at λ = 365 ± 10 nm. This OER activity compares favorably with that obtained from the non-porous CuO/CeO2 counterpart (~1.3 µmol·h−1) and pure mesoporous CeO2 (~1 µmol·h−1).
Highlights
The oxygen evolution reaction (OER) is a key chemical process in various electrochemical devices, such as rechargeable metal-air batteries and solar fuels
The mesoporous structure of the templated materials was investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD)
Mesoporous CuO/CeO2 composite semiconductors have been successfully prepared via a nano-replication technique, using mesoporous silica (SBA-15) as a solid template
Summary
The oxygen evolution reaction (OER) is a key chemical process in various electrochemical devices, such as rechargeable metal-air batteries and solar fuels. Far, little work has been conducted on the synthesis of highly porous rare-earth metal oxides and the investigation of their OER performance. These materials, showing low solar light absorption (i.e., absorbing light in the UV region), have received special attention in the fields of photovoltaics and photocatalysis because of their excellent electrical conductivity, chemical stability and reversible redox activity [10,11]. The templated synthesis via the nano-replication route appears to be a versatile method to build porous multicomponent metal oxide materials [21].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have