To develop noble-metal-free catalysts, three CoxSy samples, i.e. Co9S8, CoS and CoS2, have been prepared and investigated for the reduction of 4-nitrophenol. Co9S8 has the best surface electron immigration efficiency and the highest H2-adsorption capability, which make it the most promising catalyst. On the other hand, CoS has higher electron transfer efficiency than CoS2, leading to stronger H absorption capability. As a result, the catalytic activity of the three catalysts shows the following trend: Co9S8 > CoS > CoS2 under the same reaction conditions. Finally, a plausible catalytic mechanism has also been proposed, which is helpful in acquiring an in-depth insight into the catalytic role of CoxSy.
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http://dx.doi.org/10.1039/c8cp05309j | DOI Listing |
Langmuir
January 2025
Department of Chemistry, Faculty of Science, University of Kurdistan, Pasdaran Boulevard, Sanandaj 66177-15175, Iran.
Water splitting by an electrochemical method to generate hydrogen gas is an economic and green approach to resolve the looming energy and environmental crisis. Designing a composite electrocatalyst having integrated multichannel charge separation, robust stability, and low-cost facile scalability could be considered to address the issue of electrochemical hydrogen evolution. Herein, we report a superhydrophilic, noble-metal-free bimetallic nanostructure TiO/NiP coated on graphitic polyacrylonitrile carbon fibers (g-C/TiO/NiP) using a facile hydrothermal method followed by phosphorylation.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Science and Technology of China, National Synchrotron Radiation Laboratory, 42#, South Road of HeZuoHua, 230029, Hefei, CHINA.
Fe-N-C catalysts, with a planar D4h symmetric FeN4 structure, show promising as noble metal-free oxygen reduction reaction catalysts. Nonetheless, the highly symmetric structure restricts the effective manipulation of its geometric and electronic structures, impeding further enhancements in oxygen reduction reaction performance. Here, a high proportion of asymmetric edge-carbon was successfully introduced into Fe-N-C catalysts through morphology engineering, enabling the precise modulation of the FeN4 active site.
View Article and Find Full Text PDFAdv Mater
December 2024
College of Physics and Center of Quantum Materials and Devices, Chongqing University, Chongqing, 401331, China.
Achieving efficient and sustainable hydrogen production through photocatalysis is highly promising yet remains a significant challenge, especially when replacing costly noble metals with more abundant alternatives. Conversion efficiency with noble-metal-free alternatives is frequently limited by high charge recombination rates, mainly due to the sluggish transfer and inefficient consumption of photo-generated holes. To address these challenges, a rational design of noble-metal-free cocatalysts as oxidative sites is reported to facilitate hole consumption, leading to markedly increased H yield rates without relying on expensive noble metals.
View Article and Find Full Text PDFSmall
December 2024
College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, 310018, People's Republic of China.
The conversion of biomass into chemical fuels is exciting but quite challenging in the development of an effective conversion strategy to generate easily-separated products without energy consumption. Herein, a lignocellulosic biomass-to-H conversion system via photo-thermal catalysis over MoC hierarchical nanotube catalysts in an acidic solution, in which the lignocellulose is hydrolyzed to small organic molecules (such as glucose, etc) by dilute HSO, and then the resulting glucose is oxidized by MoC catalyst to generate H are reported. During the photo-thermal catalytic processes, the carbon vacancy in MoC catalysts results in the generation of undercoordinated Mo sites, which act as active sites for both biomass oxidation and H generation reactions.
View Article and Find Full Text PDFChemistry
December 2024
Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan, 32003, Taiwan.
Nano-sized high-entropy materials (HEMs) recently received more attention to researchers due to their superior electrochemical catalytic properties. HEMs comprise at least five elements with or without metals and are synthesized through solid-state reactions and solution-mediated techniques. The presence of many elements in these HEMs result in a high mixing entropy and facilitates the formation of stable solid solutions in fundamental crystal structures.
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