Cu₂O/Reduced Graphene Oxide Composites for the Photocatalytic Conversion of CO₂

Abstract

A facile one-step microwave-assisted chemical method has been successfully used for the synthesis of Cu2O/reduced graphene oxide (RGO) composites. Photocatalytic CO2 reduction was then investigated on the junction under ambient conditions. The RGO coating dramatically increases Cu2O activity for CO2 photoreduction to result in a nearly six times higher activity than the optimized Cu2O and 50 times higher activity than the Cu2O/RuOx junction in the 20th hour. Furthermore, an apparent initial quantum yield of approximately 0.34 % at 400 nm has been achieved by the Cu2O/RGO junction for CO2 photoreduction. The photocurrent of the junction is nearly double that of the blank Cu2O photocathode. The improved activity together with the enhanced stability of Cu2O is attributed to the efficient charge separation and transfer to RGO as well as the protection function of RGO, which was proved by XRD, SEM, TEM, X-ray photoelectron spectroscopy, photo-electrochemical, photoluminescence, and impedance characterizations. This study further presents useful information for other photocatalyst modification for efficient CO2 reduction without the need for a noble-metal co-catalyst.

Design and fabrication of semiconductor photocatalyst for photocatalytic reduction of CO2 to solar fuel

“…In another example, Cu 2 O/rGO composites exhibit a high activity for CO 2 photoreduction to CO, which is about 6 and 50 times higher than that of the optimized Cu 2 O and Cu 2 O/RuO x junction, respectively. The enhanced activity is attributed to the efficient charge separation and transfer and the protection function of rGO [248]. Similarly, the CH 4 -production rate of a rGO-CdS nanorod composite photocatalyst was increased 10-fold compared with that of the pure CdS nanorods, which was even better than that of an optimized Pt-CdS nanorod photocatalyst under the same reaction conditions [108].…”

Synthesis of hierarchical RGO@Cu2O@Cu nanocomposites: optimization of photocatalytic degradation of Direct Orange 39 using a response surface methodology

“…The photo-induced electrons and holes are formed due to the excitation of Cu 2 O under visible light [29]. In the RGO@Cu 2 O@Cu structure there are two electron transfer routes of Cu 2 O to Cu and RGO [29,30]. At Fig.…”

“…RGO@Cu sample shows the lowest activity due to the lack of Cu 2 O. In fact, Cu 2 O acts as a semiconductor that under light irradiation generates holes and electrons which are the main factors in the photocatalytic process while metallic Cu and RGO have almost no photocatalytic ability and act only as electron acceptor [29,30]. Figure 4 shows the FT-IR spectra of GO and RGO@ Cu 2 O@Cu-18h samples.…”

Formation and Characterization of Copper Nanocube-Decorated Reduced Graphene Oxide Film

“…The combination of GO with inorganic nanoparticles has led to nanocomposites with multiple functionalities that are protected against degradation by coating with a suitable material (shell) [8,9] and currently of interest for applications in biomedicine, energy production, electronics, and environmental remediation. In previous several researchers reported about rGO-Cu core-shell nanostructures synthesized by pyrolysis of organocopper [10], CVD method [11], and hydrothermal process [12].…”