In Situ Synthesis of NPC-Cu2O/CuO/rGO Composite via Dealloying and Microwave-Assisted Hydrothermal Technique

The nanoporous copper (NPC)-copper oxides (Cu2O/CuO)/reduced graphene oxide (rGO) composite structure was synthesized by combining the dealloying process of Cu48Zr47Al5 amorphous ribbons with a microwave-assisted hydrothermal technique at a temperature of 200 °C. The main advantage of the microwave-assisted hydrothermal process is the oxidation of nanoporous copper together with the in situ reduction of graphene oxide to form rGO. The integration of rGO with NPC improves electrical conductivity and streamlines the process of electron transfer. This composite exhibit considerable potential in electrochemical catalysis application, due to the combined catalytic activity of NPC and the chemical reactivity of rGO. Our study relates the transition to n-type rGO in microwave-assisted hydrothermal reactions, and also the development of an electrode material suitable for electrochemical applications based on the p-p-n junction NPC-Cu2O/CuO/rGO heterostructure. To confirm the formation of the composite structure, structural, morphological, and optical techniques as XRD, SEM/EDX, UV-Vis and Raman spectroscopy were used. The composite’s electrochemical properties were measured by EIS and Mott-Schottky analyses, showing a charge transfer resistance (Rp) of 250 Ω and indicating the type of the semiconductor properties. The calculated carrier densities of 4.2 × 1018 cm−3 confirms n-type semiconductor characteristic for rGO, and 7.22 × 1018 cm−3 for Cu2O/CuO indicating p-type characteristic.