Modification of large area Cu2O/CuO photocathode with CuS non-noble catalyst for improved photocurrent and stability

Abstract

In this work, a three-layered heterostructure Cu2O/CuO/CuS was obtained through a low-cost and large-area fabrication route comprising electrodeposition, thermal oxidation, and reactive annealing in a sulfur atmosphere. Morphological, microstructural, and compositional analysis (AFM, SEM, XRD, EDS, XPS) were carried out to highlight the surface modification of cuprous oxide film after oxidation and subsequent sulfurization. Impedance, voltammetric, and amperometric photoelectrochemical tests were performed on Cu2O, Cu2O/CuO, and Cu2O/CuO/CuS photocathodes in a sodium sulfate solution (pH 5), under 100 mW cm−2 AM 1.5 G illumination. A progressive improvement in terms of photocurrent and stability was observed after oxidation and sulfurization treatments, reaching a maximum of − 1.38 mA cm−2 at 0 V versus RHE for the CuS-modified Cu2O/CuO electrode, corresponding to a ~ 30% improvement. The feasibility of the proposed method was demonstrated through the fabrication of a large area photoelectrode of 10 cm2, showing no significant differences in characteristics if compared to a small area photoelectrode of 1 cm2.

Cu2O/CuS Nanocomposites Show Excellent Selectivity and Stability for Formate Generation via Electrochemical Reduction of Carbon Dioxide

“…Furthermore, we believe the presence of CuS is responsible for the improved electrochemical stability of Cu 2 O in the Cu 2 O/CuS nanocomposites under CO 2 RR conditions. According to previous studies, − a gradient band structure is expected to form at the heterojunction of CuS and Cu 2 O, promoting the photo-excited electron transfer from Cu 2 O to CuS and, thus, protecting Cu 2 O from reduction. Our characterization results, calculations, and long-term stability data provide indirect evidence to support this mechanism.…”

Characterization of Cu2O/CuO heterostructure photocathode by tailoring CuO thickness for photoelectrochemical water splitting

“…[2][3][4] Moreover, the Cu 2 O/CuO heterostructure is able to utilize more light than Cu 2 O photocathode because the CuO has a narrow bandgap of 1.3-1.7 eV with a high absorption coefficient. 4,[11][12][13] Due to these advantages, many Cu 2 O/CuO heterostructures have so far been suggested, such as Cu 2 O/CuO/TiO 2 , 14 Cu 2 O/CuO/CuWO 3 , 15 Cu 2 O/CuO/C, 16 Cu 2 O/CuO/CuS, 17,18 20 However, the Cu 2 O/CuO heterostructure has still not been optimized and further studied, despite its positive effect on the PEC performance.…”

Photocatalytic degradation and mineralization of dye pollutants from wastewater under visible light using synthetic CuO-VO2/TiO2 nanotubes/nanosheets

“…In addition, the satellite peaks of Cu 2p 3/2 and Cu 2p 1/2 at about 943.2 and 962.8 eV are associated with the partially filled d-block (3d 9 ) of Cu 2? and, thus, provide more evidence for the presence of CuO in nanocomposite [48]. In spectrum of V 4?…”