Catalyst-free synthesis of copper oxide composites as solar radiative filters

Abstract

Copper oxide composites were successfully synthesized by a catalyst-free method, plasma arc technology. The as-synthesized composites were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy. The analysis revealed a mixture of crystalline copper oxide (CuO), cuprous oxide (Cu2O) and copper (Cu) phases of the copper oxide composites constitute of irregularly spheroidal particlesµ with nanoparticles aggregate on the surface. Gas pressure during plasma arc process noticeably influences the composition and solar radiative properties of the composite materials. Among the samples studied, the composites synthesized with an arc current of 80 A and a pressure of 300 Torr exhibited the highest near infrared diffuse reflectance, providing a total solar reflectance of 22.96%. The mixed phase composition together with the nanostructures among the composites are considered to contribute to the excellent near infrared reflectance of copper oxide composites. Low reflectance in the visible region combined with high reflectance in the near infrared region make this composite material a good candidate for solar reflective coating which will demonstrate black appearance but keep a cool surface under solar irradiation.

Oxalic acid-derived combustion synthesis of multifunctional nanostructured copper oxide materials

“…This reflectance value is relatively low as compared to other binary oxides [12,65], for instance, CeO 2 , MgO, Al 2 O 3 , TiO 2 , and ZnO. The CuO composites having Cu 2 O and Cu phases with irregularly shaped nanoparticles showed high reflectance in the NIR region that makes the composites material a good candidate for solar reflective coating, despite the black appearance [69].…”

Calcination Strategy for Scalable Synthesis of Pithecellobium-Type Hierarchical Dual-Phase Nanostructured CuxO to Columnar Self-Assembled CuO and Its Electrochemical Performances

“…The rational design of energy storage devices or platforms that shows excellent performance greatly depends on the electrode materials. Therefore, top priority has given to explore widely acceptable electrode materials for the development of cost-effective, safe, and high-capacitive, multidimensional mode of energy storage devices, which is desperately warranted for sustainable and green technology. , Among all the energy storage devices, the electrochemical supercapacitors, either electrical double-layer capacitors (EDLCs) or pseudocapacitors are promising devices in the field of energy storage as they have a high power density, energy density, a rapid charge–discharge rate, and an excellent cyclic stability. − For these advantages, emphasis has given to pure/binary or ternary oxides based on transition metals as one of the best candidate material. − In this context, mostly ongoing R&D is focused on engineering an effective preparation method for manipulating surface activities, the crystal structure, and the morphology to obtain optimal electrochemical properties. − Again, scalable synthesis and wide availability of the precursor metal ions along with their consistency in the supply chain are the major challenges for establishing the future emerging technology. Among them, copper-based oxides are significantly addressing most of the issues because of their worldwide available resources, being environmentally friendly, and possessing manipulative specific capacitance. − To achieve its theoretical capacity, the pseudocapacitance of CuO is 1800 F/g and that of Cu 2 O is up to 2247 F/g .…”