Light-to-Hydrogen Improvement Based on Three-Factored Au@CeO₂/Gr Hierarchical Photocatalysts

Abstract

Recently, various attempts have been made for light-to-fuels conversion, often with limited performance. Herein we report active and lasting three-factored hierarchical photocatalysts consisting of plasmon Au, ceria semiconductor, and graphene conductor for hydrogen production. The Au@CeO2/Gr2.0 entity (graphene outer shell thickness of 2.0 nm) under visible-light irradiation exhibits a colossal achievement (8.0 μmol mgcat –1 h–1), which is 2.2- and 14.3-fold higher than those of binary Au@CeO2 and free-standing CeO2 species, outperforming the currently available catalysts. Yet, it delivers a high maximum quantum yield efficiency of 38.4% at an incident wavelength of 560 nm. These improvements are unambiguously attributed to three indispensable effects: (1) the plasmon resonant energy is light-excited and transferred to produce hot electrons localizing near the surface of Au@CeO2, where (2) the high-surface-area Gr conductive shell will capture them to direct hydrogen evolution reactions, and (3) the active graphene hybridized on the defect-rich surface of Au@CeO2 favorably adsorbs hydrogen atoms, which all bring up thorough insight into the working of a ternary Au@CeO2/Gr catalyst system in terms of light-to-hydrogen conversion.

CeO2 Nanoparticles Modified on Graphite Sheet Electrodes for Photoelectrochemical Tobacco Wastewater Detection, Degradation, and Toxicity Measurement

“…23 4a). The CeO 2 -GS exhibited a higher response to ON/OFF behavior, compared to the bare GS indicating a very low cathodic photocurrent 24 of the as-prepared CeO 2.…”

“…From the Mott− Schottky plot, the E fb was calculated as −0.67 V, and a positive slope was observed, indicating that CeO 2 is an n-type material. 24 Figure 4d shows the energy band diagram of CeO 2 NPs. The synthesized CeO 2 showed an n-type behavior with a bandgap energy of 3.21 eV.…”

“…The Mott–Schottky measurements were performed at a potential between −1.5 and 0 V with a frequency of 100 kHz; Mott–Schottky experiments were used to determine the flat band potential ( E fb ) of the CeO 2 NPs. From the Mott–Schottky plot, the E fb was calculated as −0.67 V, and a positive slope was observed, indicating that CeO 2 is an n-type material …”

Decoupled hydrogen evolution from water/seawater splitting by integrating ethylene glycol oxidation on PtRh0.02@Rh nanowires with Rh atom modification

“…[1][2][3][4][5][6] Hydrogen is a clean, renewable energy that has the advantages of safety and high efficiency, and it has been considered to be the most suitable energy source for sustainable development strategies. [7][8][9][10][11] Electrochemical seawater splitting is an efficient and feasible hydrogen production technology that is pollution-free with facile operation, and thus, extensive developmental research is currently being conducted. [12][13][14] There are two main half-reactions for the seawater electrolysis process: the hydrogen evolution reaction (HER) occurs on the cathodic electrode, and the oxygen evolution reaction (OER) occurs on the anodic electrode.…”

“…1–6 Hydrogen is a clean, renewable energy that has the advantages of safety and high efficiency, and it has been considered to be the most suitable energy source for sustainable development strategies. 7–11 Electrochemical seawater splitting is an efficient and feasible hydrogen production technology that is pollution-free with facile operation, and thus, extensive developmental research is currently being conducted. 12–14…”