Biotemplated g-C₃N₄/Au Periodic Hierarchical Structures for the Enhancement of Photocatalytic CO₂ Reduction with Localized Surface Plasmon Resonance

Abstract

Graphitic carbon nitride (g-C3N4) is a promising photocatalyst for CO2 reduction to alleviate the greenhouse effect. However, the low light absorption, small specific surface area, and rapid charge recombination limit the photocatalytic efficiency of g-C3N4. Herein, we demonstrate a bioinspired nanoarchitecturing strategy to significantly improve the light harvesting and charge separation of the g-C3N4/Au composite, as proven by the remarkable photocatalytic CO2 reduction. Specifically, a biotemplating approach is employed to transfer the sophisticated hierarchical structures and the related light-harvesting functionality of Troides helena butterfly wings to the g-C3N4/Au composite. The resulting g-C3N4/Au composite shows high photocatalytic efficiency under UV–visible excitation with triethanolamine as the sacrificial agent. The yields of CO and CH4 are 331.57 and 39.71 μmol/g/h, respectively, which are ∼36 times and ∼88 times that of pure g-C3N4 under the same conditions. Detailed experiments and the finite-difference time-domain method suggest that the superb photocatalytic activity should be ascribed to the unique periodic hierarchical structure which assists the light absorption and the localized surface plasmon resonance for promoted charge separation in addition to the more effective CO2 diffusion and larger specific surface area. Our work provides a new path for the design and optimization of photocatalysts based on biological structures that are usually unattainable artificially.

Emerging carbon-based quantum dots for sustainable photocatalysis

“…This confirms the full absorption and utilization of near-infrared light by CNQDs and the excellent performance of CNQDs in photocatalytic CO 2 conversion. 126 Based on the application of g-C 3 N 4 in photocatalysis, [127][128][129][130] later scholars further utilized CNQDs in photocatalytic CO 2 reduction and achieved satisfactory results. For instance, CNQD-decorated mesoporous CeO 2 composite photocatalyst was prepared by the hydrothermal method.…”

“…As a derivative of MXenes, MQDs have also been reported to be suitable for photocatalytic CO 2 reduction. [125][126][127][128][129][130][131][132][133][134] He et al constructed the 2D/2D/0D TiO 2 /C 3 N 4 /Ti 3 C 2 MXene heterojunction, in which the edge-capped 0D Ti 3 C 2 QDs (TCQD) are grown on the surface of g-C 3 N 4 through electrostatic interactions. The advantages of the heterogeneous structure in photocatalytic CO 2 reduction are higher yields of CH 4 and CO, as well as much better stability than a single precursor catalyst; this confirms the important role of the introduction of TCQD on improving the photocatalytic activity of TiO 2 /g-C 3 N 4 (Fig.…”

Engineering Z-Scheme FeOOH/PCN with Fast Photoelectron Transfer and Surface Redox Kinetics for Efficient Solar-Driven CO2 Reduction

“…From Figure a and Figure S9, FeOOH and PCN exhibit band gaps of 2.45 and 2.80 eV as obtained from Tauc plots, , respectively, both endowing a broad response to the solar spectrum. The method is based on the correlation between (α hv ) 2 and hv (α is the absorption coefficient, h is the Planck constant, ν is the photon’s frequency) and indicates a straight line whose intercept on the energy axis gives a band gap . The composite of FeOOH and PCN exhibits intermediate light absorption between the two counterparts.…”

“…From the transmission electron microscopy (TEM) and EDX elemental mapping images in Figure 1f,g and Figure S7a, it can be seen that FeOOH was uniformly dispersed on PCN in the form of a nanorod with diameters of 15−25 nm and lengths of 150−300 Further investigations show that the band structure of PCN well matches with that of FeOOH. From Figure 2a and Figure S9, FeOOH and PCN exhibit band gaps of 2.45 and 2.80 eV as obtained from Tauc plots, 16,40 respectively, both endowing a broad response to the solar spectrum. The method is based on the correlation between (αhv) 2 and hv (α is the absorption coefficient, h is the Planck constant, ν is the photon's frequency) and indicates a straight line whose intercept on the energy axis gives a band gap.…”

Nanoarchitectonics of g-C3N4 Nanosheets with a AuCu Enhancement Effect for Superior Photo- and Electrochemical Activity

“…Because the introduction of single metals did not improve the properties of g-C 3 N 4 too much, preparation of bimetallic co-catalysts is put on the agenda. Until now, almost all metal elements have been introduced in g-C 3 N 4 -based photocatalysts to adjust the photocatalytic activity, such as bimetallic cocatalysts PtNi/g-C 3 N 4 , AuPd/g-C 3 N 4 , AuPt/g-C 3 N 4 , CuAg/g-C 3 N 4 , and CuFe/g-C 3 N 4 . − To sum up, noble-metal NPs with the LSPR effect could effectively harvest ultraviolet (UV) and visible light, which will provide more energy to break obstacles for photocatalytic reactions. As for non-noble metals, they are introduced into a g-C 3 N 4 framework to adjust the transmission efficiency of electrons and enhance photocatalytic activities .…”