A low overpotential photoelectrochemical reduction of carbon dioxide to methanol with highly photoactive hierarchical structured cuprous oxide. Issue 16 (November 2020)

• Record Type: Journal Article
• Authors: Minggu, Lorna Jeffery; Salehmin, Mohd Nur Ikhmal; Mohamed, Mohammad Azuwa; Arifin, Khuzaimah; Yunus, Rozan Mohamad; Kassim, Mohammad B.
• Is Part Of: Ceramics international. Volume 46:Issue 16(2020)Part A
• Page Start: 26004
• Page End: 26016
• Publication Date: 2020-11
• Subjects: Cuprous oxide -- Nanowire -- Photoelectrochemical -- CO2 reduction -- Methanol; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.07.091
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this study, two different highly scalable hierarchical structured photocathodes of Cu2 O nanowire (NW) and microyarn (MY), were prepared and evaluated for their photoelectrochemical (PEC) reduction of CO2 (PECRC) to methanol activity. Notably, Cu2 O NW showed a considerably higher photoactivity than Cu2 O MY, and the highest ever reported in terms of photoconversion efficiency in comparison with similar material. The enhancement is ascribed to the increased in light entrapment, carrier density, and reduced charge transfer resistance as a result of highly dense and uniform NW arrays. Additionally, the PECRC to methanol for both Cu2 O photocathodes in this study was operated at considerably low positive bias potential (+0.2 V vs. Ag/AgCl). The yield for methanol achieved in this study is also comparable to that of surface-modified Cu2 O photocathode prepared by using a more costly technique. The physicochemical characterization of the photocathodes after the PECRC reaction revealed a periodical appearance of CuCO3 .Cu(OH)2, Cu, and CuO on the Cu2 O photocathode after the PECRC reaction, which is hypothesized to work synergistically during the PECRC to methanol. Without surface modification, bare Cu2 O was adequate to catalyze PECRC to methanol. Overall, the integration of highly scalable and photoactive Cu2 O NW photocathode and considerably low overpotential for PECRC will be a promising approach to realize the PECRC to methanol in the future. Graphical abstract: Image 1 Highlights: The photoactivity of Cu2 O nanowire (NW) is higher than Cu2 O microyarn (MY. Cu2 O NW has higher light entrapment, carrier density, and reduced charge transfer resistance than the Cu2 O MY. A low overpotential for photoelectrochemical reduction of CO2 (PECRC) to methanol with hierarchical structured Cu2 O. The methanol yield is comparable to that of reported Cu2 O, which produced by a costly technique. Cu2 O, Cu, CuO, CuCO3 .Cu(OH)2 were suggested to work synergistically during PECRC.