Herein, a new type of photocatalysts, Au nanodots@thiol-UiO-66@ZnIn2S4 nanosheets (Au@UiOS@ZIS), is elaborately designed for the photocatalytic H2 evolution from water splitting, where Au nanodots (NDs) are anchored in the pore space of thiol-functionalized UiO66 metal-organic framework (MOF) and ZnIn2S4 nanosheets are wrapped around the UiO66 MOF containing Au NDs. It is found that the different Au positions have a grateful effect on the transfer of photogenerated charge carriers. In Au@UiOS@ZIS, the photoexcited electrons transfers from ZnIn2S4 to UiOS and then to Au NDs, establishing a smooth transmission channel of electrons. As expected, the optimal sample (Au4@UiOS@ZIS40) presents a high photocatalytic H2 production rate of 391.6 μmol/h (10 mg of catalyst) under visible light irradiation, which is 435.1, 61.2 and 10.2 times higher than that of the pure UiOS, ZnIn2S4 and UiOS@ZIS, respectively.

Au nanodots@thiol-UiO66@ZnIn2S4 nanosheets with significantly enhanced visible-light photocatalytic H2 evolution: The effect of different Au positions on the transfer of electron-hole pairs

In this research update, we discuss the visible-light photocatalysis. Due to the potential of utilizing freely available solar energy for environmental remediation and fuel generation, this topic has been of increasing interest. Huge amount of work has been done in developing a large variety of photocatalyst materials, and advances have been made in understanding the process. Nevertheless, substantial challenges remain. Some of those challenges could possibly be solved by developing better materials, but in many cases, the biggest problem is whether photocatalysis could be scaled up to an industrial process that would be cost-competitive to existing technologies. Here, we discuss different types of visible-light photocatalysts and their applications and outline various challenges that need to be addressed in the development of practically relevant materials and systems.

Visible-light photocatalysts: Prospects and challenges

Heterojunction photocatalysts are widely adopted for efficient water splitting, but ion migration can seriously threaten the stability of heterojunctions, as with the well-known low stability of CdS-Cu2-xS due to intrinsic Cu+ ion migration. Here, we utilize Cu+ migration to design a stratified CdS-Cu2-xS/MoS2 photocatalyst, in which CuI@MoS2 (CuI-intercalated within the MoS2 basal plane) is created by Cu+ migration and intercalation to the adjacent MoS2 surface. The epitaxial vertical growth of the CuI@MoS2 nanosheets on the surface of one-dimensional core-shell CdS-Cu2-xS nanorods forms catalytic and protective layers to simultaneously enhance catalytic activity and stability. Charge transfer is verified by kinetics measurements with femtosecond time-resolved transient absorption spectroscopy and direct mapping of the surface charge distribution with a scanning ion conductance microscope. This design strategy demonstrates the potential of utilizing hybridized surface layers as effective catalytic and protective interfaces for photocatalytic hydrogen production.

MoS2-Stratified CdS-Cu2-xS Core-Shell Nanorods for Highly Efficient Photocatalytic Hydrogen Production.

The successful development of artificial photosynthesis requires finding new materials able to efficiently harvest sunlight and catalyze hydrogen generation and carbon dioxide reduction reactions. Plasmonic nanoparticles are promising candidates for these tasks, due to their ability to confine solar energy into molecular regions. Here, we review recent developments in hybrid plasmonic photocatalysis, including the combination of plasmonic nanomaterials with catalytic metals, semiconductors, perovskites, 2D materials, metal–organic frameworks, and electrochemical cells. We perform a quantitative comparison of the demonstrated activity and selectivity of these materials for solar fuel generation in the liquid phase. In this way, we critically assess the state-of-the-art of hybrid plasmonic photocatalysts for solar fuel production, allowing its benchmarking against other existing heterogeneous catalysts. Our analysis allows the identification of the best performing plasmonic systems, useful to design a new generation of plasmonic catalysts.

/pdf/hybrid-plasmonic-nanomaterials-for-hydrogen-generation-and-3103jdqa.pdf

Hybrid Plasmonic Nanomaterials for Hydrogen Generation and Carbon Dioxide Reduction

L-Cysteine capped Mo2C/Zn0.67Cd0.33S heterojunction with intimate covalent bonds enables efficient and stable H2-Releasing photocatalysis

Localized surface plasmon resonance (LSPR) offers a valuable opportunity to improve the efficiency of photocatalysts. However, plasmonic enhancement of photoconversion is still limited, as most of metal-semiconductor building blocks depend on LSPR contribution of isolated metal nanoparticles. In this contribution, the concept of collective excitation of embedded metal nanoparticles is demonstrated as an effective strategy to enhance the utilization of plasmonic energy. The contribution of Au-nanochain to the enhancement of photoconversion is 3.5 times increase in comparison with that of conventional isolated Au nanoparticles. Experimental characterization and theoretical simulation show that strongly coupled plasmonic nanostructure of Au-nanochain give rise to highly intensive electromagnetic field. The enhanced strength of electromagnetic field essentially boosts the formation rate of electron-hole pair in semiconductor, and ultimately improves photocatalytic hydrogen evolution activity of semiconductor photocatalysts. The concept of embedded coupled-metal nanostructure represents a promising strategy for the rational design of high-performance photocatalysts.

/pdf/collective-excitation-of-plasmon-coupled-au-nanochain-boosts-a292oxptud.pdf

Jun Qian

Papers

Collective excitation of plasmon-coupled Au-nanochain boosts photocatalytic hydrogen evolution of semiconductor.