A "surface patching" strategy to achieve highly efficient solar water oxidation beyond surface passivation effect. (December 2019)

• Record Type: Journal Article
• Authors: Jin, Bingjun; Cho, Yoonjun; Zhang, Yan; Chun, Do Hyung; Li, Ping; Zhang, Kan; Lee, Kug-Seung; Park, Jong Hyeok
• Is Part Of: Nano energy. Volume 66(2019)
• Publication Date: 2019-12
• Subjects: Water oxidation -- Photoanode/electrolyte interface -- Disordered layer -- Defect patching; 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.2019.104110
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The hole trapping sites at the photoanode/electrolyte interface seriously detract from the positive effect of oxygen-vacancy on photoelectrochemical (PEC) water oxidation. In this work, a "patching" strategy is put forward to eliminate those charge trapping sites of the oxygen-deficient in disordered overlayer (DL) of WO3 photoanode by inactive pieces of oxygen-rich carbon nitride quantum dots (CNQDs). The "patching" leads to a 1.5-fold enhancement in PEC performance and a 100 mV cathodic shift of onset potential compared to the pre-optimized DL-WO3 photoanode. The remarkably raised charge transfer efficiency from 60% to 87% at 1.23 V vs RHE is an indication of boosting hole transfer. Density function theory (DFT) calculations reveal that DL-WO3 /CNQDs produces a stepped valence band alignment together with the removal of charge trapping sites, is capable of overcoming the hole transfer limitation at the photoanode/electrolyte interface. This study might open a window to pursue a simple but highly efficient strategy on modification of solid/liquid interface for solar to fuel conversion. Graphical abstract: Image 1 Highlights: A "surface patching" strategy was put forward to eliminate charge trapping sites. Oxygen-enriched CNQDs patched the surface defects by chemisorbed interaction. The patched photoanodes possess high photocurrent density and low onset potential. Open a window to modify the solid/liquid interface for solar to fuel conversion.