Changes in agricultural practices enabled the circulation of N-containing species, making converting nitrate into ammonia (fertilizer) highly desirable. Herein, we propose a photosystem composed of NiO/Au plasmon/TiO2 that selectively produces ammonia from nitrates at neutral pH and room temperature with visible light via a combination of electrochemical and plasmon hot electrons (i.e., it is a photoelectrochemical process). The system effectively suppresses the undesirable hydrogen evolution reaction and converts the superfluous hot holes into atmospheric oxygen. The role of the hot electrons is to boost catalytic performance, enabling higher reaction rates at lower potentials. The process paves the way for agricultural practices that recycle nutrients, improving process circularity and reducing fertilizer costs.
More sustainable solutions are needed to produce chemicals and fuels, mainly to face rising demands and mitigate climate change. Light, as a reagent, has emerged as a route to activate small molecules, e.g., H2O, CO2, N2, and make complex chemicals in a process called photocatalysis. Several photosystems have been proposed, with plasmonic technology emerging as one the most promising technologies due to its high optical absorption and hot-carrier formation. However, the lifetime of hot carriers is unsuitable for direct use; therefore, they are normally coupled with suitable charge-accepting materials, such as semiconductors. Herein, a system is reported consisting of Au supported in p-Cu2O. The combination of p-Cu2O intrinsic photoactivity with the plasmonic properties of Au extended the system’s optical absorption range, increasing photocatalytic efficiency. More importantly, the system enabled us to study the underlying processes responsible for hot-hole transfer to p-Cu2O. Based on photocatalytic studies, it was concluded that most of the holes involved in aniline photo-oxidation come from hot-carrier injections, not from the PIRET process.
There is an urgent need for efficient solutionprocessable p-type semiconductors. Copper(I) iodide (CuI) has attracted attention as a potential candidate due to its good electrical properties and ease of preparation. However, its carrier dynamics still need to be better understood. Carrier dynamics after bandgap excitation yielded a convoluted signal of free carriers (positive signal) and a negative feature, which was also present when the material was excited with sub-bandgap excitation energies. This previously unseen feature was found to be dependent on measurement temperature and attributed to negative photoconductivity. The unexpected signal relates to the formation of polarons or strongly bound excitons. The possibility of coupling CuI to plasmonic sensitizers is also tested, yielding positive results. The outcomes mentioned above could have profound implications regarding the applicability of CuI in photocatalytic and photovoltaic systems and could also open a whole new range of possible applications.
Plasmonic systems convert light into electrical charges and heat that mediate catalytic transformations. However, the debate about the involvement of hot carriers in the catalytic process remains shredded in controversy. Here, we demonstrate the direct use of plasmon hot electrons in the hydrogen evolution with visible light. A plasmonic nanohybrid system consisting of NiO/Au/[CoII(phen-NH2)2(H2O)2] (phen-NH2 = 1,10-Phenanthrolin-5-amine) that is unstable at water thermolysis temperatures was consciously assembled, ensuring that the plasmon contribution to the catalytic process is solely from hot carriers. With the combination of photoelectrocatalysis and advanced in situ spectroscopies, one could establish the reaction mechanism, which consisted of electron injection into the phenanthroline-ligands followed by two quick, concerted proton-coupled electron transfer steps resulting in the evolution of hydrogen. Light-driven hydrogen evolution with plasmons provides a sustainable route for producing green hydrogen, which modern society strives to achieve.
Plasmonic systems effectively convert light into electrical charges and heat, which can mediate catalytic transformations. There are many examples of plasmonic photothermal catalytic reactions, but the involvement of hot carriers in the catalytic process remains a matter of intense debate and controversy. Here, we demonstrate the direct use of plasmon hot electrons in the photoelectrocatalytic CO2 reduction with visible light. A purposely assembled plasmonic nanohybrid system consisting of NiO/Au/ReI(phen-NH2)(CO)3Cl (phen-NH2 = 10-Phenanthrolin-5-amine) enabled direct access into hot-carrier-mediated reaction pathways by ultrafast spectroscopy, electrochemistry and catalytic testing. The ReI(phen-NH2)(CO)3Cl complex decomposes above 305°C, limiting thermal CO2 reduction contribution, making the plasmonic hot carriers the prime culprit for the process. Plasmonic light activation of CO2 provides a sustainable route for producing carbon fuels and feedstocks for society.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.