Unique three dimensional architecture using a metal-free semiconductor cross-linked bismuth vanadate for efficient photoelectrochemical water oxidation. (June 2016)

• Record Type: Journal Article
• Authors: Su, Jingyang; Bai, Zhaowen; Huang, Baoling; Quan, Xie; Chen, Guohua
• Is Part Of: Nano energy. Volume 24(2016:Jun.)
• Page Start: 148
• Page End: 157
• Publication Date: 2016-06
• Subjects: Solar water oxidation -- Bismuth vanadate -- Graphene -- Carbon nitride -- Photoelectrochemical; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2016.04.032
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: In this study, we report a unique design of nano-porous bismuth vanadate (BiVO4 ) photoelectrode decorated with graphene linked carbon nitride (GCN) nanosheets and their potential application in solar driven photoelectrochemical water oxidation. Especially, an integrated sandwich-like heterojunction with highly interconnected porous structure, comprising two dimensional GCN sheets and three dimensional BiVO4 was successfully synthesized with significantly enhanced photoelectrochemical activity. The prepared photoelectrode achieves up to 1.98 mA cm −2 (1.23 V vs RHE) under AM 1.5G solar light irradiation, 2.06 times compared with pristine BiVO4 (0.96 mA cm −2 at 1.23 V vs RHE). After deposition of cobalt phosphate nanoparticles as water-oxidation electrocatalyst, a plateau photocurrent of 3.42 mA cm −2 (1.23 V vs RHE) with a maximum photo-conversion efficiency of 1.28% was achieved on the prepared photoanode. The highly improved photoelectrochemical performance can be attributed to suitable band matching facilitating efficient charge separation between GCN and BiVO4 as well as the desirable incorporation of rational designed dimensionality-dependent heterojunction for promoted solar energy utilization. More importantly, the combined experimental results and computational simulations reveal that the strong donor-acceptor coupling between GCN sheets and porous BiVO4 facilitates the separation and transfer of photoinduced electron-hole pairs, accounting for the highly promoted photoelectrochemical performance. Graphical abstract: Highlights: Graphene linked carbon nitride (GCN) nanosheets were demonstrated as a sensitizer to modify BiVO4 for the first time. The sandwich-like GCN/BiVO4 photoelectrode exhibited 206% enhanced photoresponse compared with pristine BiVO4 . Co–Pi/GCN/BiVO4 showed photocurrent density of 3.42 mA cm −2 at 1.23 V vs RHE under AM 1.5G with a photo-conversion efficiency of 1.28%. Computational simulations demonstrate strong donor-acceptor coupling between GCN sheets and porous BiVO4 .