Au@Cu₂O Core–Shell and Au@Cu₂Se Yolk–Shell Nanocrystals as Promising Photocatalysts in Photoelectrochemical Water Splitting and Photocatalytic Hydrogen Production

Abstract

In this work, we demonstrated the practical use of Au@Cu2O core–shell and Au@Cu2Se yolk–shell nanocrystals as photocatalysts in photoelectrochemical (PEC) water splitting and photocatalytic hydrogen (H2) production. The samples were prepared by conducting a sequential ion-exchange reaction on a Au@Cu2O core–shell nanocrystal template. Au@Cu2O and Au@Cu2Se displayed enhanced charge separation as the Au core and yolk can attract photoexcited electrons from the Cu2O and Cu2Se shells. The localized surface plasmon resonance (LSPR) of Au, on the other hand, can facilitate additional charge carrier generation for Cu2O and Cu2Se. Finite-difference time-domain simulations were carried out to explore the amplification of the localized electromagnetic field induced by the LSPR of Au. The charge transfer dynamics and band alignment of the samples were examined with time-resolved photoluminescence and ultraviolet photoelectron spectroscopy. As a result of the improved interfacial charge transfer, Au@Cu2O and Au@Cu2Se exhibited a substantially larger photocurrent of water reduction and higher photocatalytic activity of H2 production than the corresponding pure counterpart samples. Incident photon-to-current efficiency measurements were conducted to evaluate the contribution of the plasmonic effect of Au to the enhanced photoactivity. Relative to Au@Cu2O, Au@Cu2Se was more suited for PEC water splitting and photocatalytic H2 production by virtue of the structural advantages of yolk–shell architectures. The demonstrations from the present work may shed light on the rational design of sophisticated metal–semiconductor yolk–shell nanocrystals, especially those comprising metal selenides, for superior photocatalytic applications.

Optimized electromagnetic enhancement and charge transfer in MXene/Au/Cu2O hybrids for achieving efficient SERS

“…The Cu 2p 3/2 peaks of MXene/Au/Cu 2 O shift to a lower energy region compared with Au/Cu 2 O and Cu 2 O, indicating that possible charge transfer from Au to Cu 2 O, and MXene to Au/Cu 2 O. 60 Fig. 3f presents the Ti 2p spectra of MXene and MXene/Au/Cu 2 O hybrids.…”

Dandelion-Like Nanostructured Cu/Cu2O Heterojunctions with Fast Diffusion Channels Enabling Rapid Photocatalytic Pollutant Removal

“…To further improve the performance, the structural modulation has been identified as another effective approach for Cu/Cu 2 O nanocomposite catalysts. By constructing the hollow nanostructure, the surface area and the reactive sites can be significantly increased, so that the inner cavity can be fully utilized and the photocatalytic performance can be enhanced. − Yan et al prepared Cu/Cu 2 O hollow nanospheres for rapid photodegradation of methyl orange (MO) under visible light irradiation due to the porous nanocrystalline shell structure for solution penetration and unique heterojunction for carrier separation . Further research has demonstrated that the hollow structure can affect the solution diffusion for improving the photocatalytic performance.…”

Effect of Calcination Temperature on Structural, Morphological and Optical Properties of Copper Oxide Nanostructures Derived from Garcinia mangostana L. Leaf Extract

“…The CuO NPs exhibit excellent electrical, optical, magnetic phase, antioxidant and antimicrobial properties [ 2 , 3 , 20 ], which is useful in anti-cancer, biomedical imaging, drug and cellular deliveries, wound healing, and disease treatment, and they act as a heterogeneous catalysis [ 3 , 18 , 23 , 24 ]. In recent development, CuO NPs have great potential in various field of applications, which include advanced photocatalytic processes [ 25 ], environmental and energy conversion [ 26 ], green production of hydrogen, photoelectrochemical water splitting [ 27 ], organic pollutants’ photodegradation, generation of solar fuel and photovoltaic devices [ 28 ].…”