Obtaining high efficiency room temperature phosphorescence (RTP) by employing non-noble metals poses two challenges: (1) strengthening spin-orbit coupling of excitons to improve the rate of intersystem crossing (ISC) by using non-noble metals with small-atomic-number; (2) employing structural confinement to enhance radiation relaxation because harsh conditions, including carefully selected matrices, rigid solid-state crystalline structure and low temperature, are commonly needed. Here, layered double hydroxides (LDHs) with orderly non-noble metal arrangements were used as an inorganic matrix to activate RTP of carbon dots (CDs). The Zn orderly arranged on the LDH layer contributes to the enhancement in spin-orbit coupling of excitons and the decrease in the energy gap for the singlet-triplet state. The structural confinements of the LDH layer and nano-interlayer testify that the phosphorescence of CDs-LDHs originates from the suppressed radiationless relaxation processes. Using the high tunability of metal species and ratios on the LDH layer, this method can be widely applied to optimize ISC and phosphorescence properties.
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http://dx.doi.org/10.1039/c6nr09648d | DOI Listing |
Adv Mater
December 2024
State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, P. R. China.
Nickel-iron layered double hydroxides (NiFe LDHs) are considered as promising substitutes for precious metals in oxygen evolution reaction (OER). However, most of the reported NiFe LDHs suffer from poor long-term stability because of the Fe loss during OER resulting in severe inactivation. Herein, a dynamically stable chelating interface through in situ transformation of asymmetric aldehyde-ligand (THB, 1,3,5-Tris(3'-hydroxy-4'-formylphenyl)-benzene) modified NiFe LDHs to anchor Fe and significantly enhance the OER stability is reported.
View Article and Find Full Text PDFACS Appl Nano Mater
January 2024
Department of Chemistry, University of Central Florida, Orlando, Florida 32816 (USA).
Understanding the origin of enhanced catalytic activity is critical to heterogeneous catalyst design. This is especially important for non-noble metal-based catalysts, notably metal oxides, which have recently emerged as viable alternatives for numerous thermal catalytic processes. For thermal catalytic reduction/hydrogenation using metal oxide nanoparticles, enhanced catalytic performance is typically attributed to increased surface area and oxygen vacancies.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China.
Developing highly active and durable non-noble metal catalysts is crucial for energy conversion and storage, especially for proton exchange membrane fuel cells (PEMFCs) and lithium-oxygen (Li-O) batteries. Non-noble metal catalysts are considered the greatest potential candidates to replace noble metal catalysts in PEMFCs and Li-O batteries. Herein, we propose a novel type of non-noble metal catalyst (Fe-Hf/N/C) doped with Hf into a mesoporous carbon material derived from Hf-ZIF-8 and co-doping with Fe and N, which greatly enhanced the activity and durability of the catalyst.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
The conversion of methane and carbon dioxide to form C products is of great interest but presents a long-standing grand challenge due to the significant obstacle of activating the inert C-H and C═O bonds as well as forming the C-C bonds. Herein, the consecutive C-C coupling of CH and CO was realized by using heteronuclear metal cations CuTa, and the desorption of HC═C═O molecules was evidenced by state-of-the-art mass spectrometry. The CuTa reaction system is significantly different from the homonuclear metal systems of Cu and Ta.
View Article and Find Full Text PDFChemSusChem
December 2024
Soongsil University, Department of Chemistry, 06978, Seoul, KOREA, REPUBLIC OF.
MXene 2D materials and non-noble transition metal oxide nanoparticles have been proposed as novel pH-universal platforms for oxygen evolution reaction (OER), owing to the enhancement of active site exposures and conductivity. Herein, Co3O4-RuO2 /Ti3C2Tx/carbon cloths (CRMC) were assembled in a facile way as an efficient OER platform through a hydrothermal process. The Co3O4-RuO2/Ti3C2Tx demonstrated prominent OER catalytic performance under acidic and alkaline conditions, which showed overpotential values of 195 and 247 mV at 10 mA cm-2 with Tafel slopes of 93 and 97 mVdec-1, respectively.
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