A surfactant free template assisted electrodeposition method was used to fabricate thick n‐type Cu2O films having cubic nanostructures for the detection of liquefied petroleum (LP) gas at low concentrations. Templates were fabricated by initially electrodepositing a p‐type Cu2O thin film on a Ti substrate followed by annealing that changed conductivity type of the film, as confirmed by Mott–Schottky and spectral response measurements. SEM measurements of resulting films showed nano‐cubic crystals having sizes of 150–300 nm. When exposed to a mixture of LP gas and dry air, the resistance of these films increased and the maximum response was recorded when films were maintained at 180 °C for all concentrations and it was independent of the surface morphology. At 180 °C, at the lowest tested LP gas concentration of 2 vol.%, a twofold increase in response was observed in the nano‐cubic films compared to the micro‐crystalline n‐type Cu2O films. This improvement in gas response is attributed to increased effective surface area of these nanostructured films. Compared to other LP gas sensing materials, Cu2O films showed very good response times and recovery times of ∼120 and ∼90 s, respectively.

A photocatalytic composite in powder form having nanosized Cu2O/Cu granules wrapped in multilayered reduced graphene oxide (rGO) sheets was synthesized. The fabrication process was initiated by potentiostatic electrodeposition of n-type Cu2O thin films on Ti substrates in an acetate bath. Peeled-off Cu2O thin films were next subjected to ultrasonic mixing with graphene oxide (GO) by maintaining a Cu2O/GO mass ratio of 125:10. Chemical reduction using ascorbic acid converted Cu2O partially to Cu, while converting GO completely to rGO as confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Transmission electron microscopy (TEM) images of the composite confirmed the presence of Cu nanoparticles of the size of tens of nanometers within the photocatalyst, Cu2O. The fabrication process therefore implicitly favors synthesis of nanosized Cu playing the role of a co-catalyst. The Cu2O/Cu/rGO composite showed significantly higher ability to degrade methylene blue in solution, while the effects due to photocorrosion were minimal during a month of testing when compared with Cu2O alone. The layered rGO provides an effective medium for transporting photoelectrons to the reactant while inhibiting photocorrosion. Furthermore, the composite demonstrated its ability to split water under visible light in the presence of methanol and creates a promising platform to further develop a variety of other photocatalytic applications.

Amperometric sensing measurements of glucose were performed using n‐Cu2O nano‐cubic films fabricated on Ti using a surfactant free template aided electrodeposition method. The electrochemical performance of these films in the presence of aqueous glucose was characterized by cyclic voltammetry and chronoamperometry. Amperometric sensing measurements of glucose for the nano‐cubic Cu2O/Ti electrode were significantly better than the microcrystalline counterpart prepared under similar electrodeposition conditions without the aid of a template. Measurements yielded a sensitivity of 28.4 ± 0.2 µA mM−1 cm−2 at an applied potential of +0.6 V with a lower detection limit of 15.6 µM and a linear range of detection from 17 to 11,650 μM. The linear range is one of the best ever reported, for a copper oxide‐based amperometric glucose sensing electrode. Films were characterized using XRD and SEM.