Sequential catalytic growth provides an efficient tool for the synthesis of carbon nanotubes periodically inserted with catalyst nanoparticles. Several synthesis parameters were found crucial in order to induce this particular growth mechanism. The presence of phosphorus is required to form metal phosphide particles active for the formation of carbon nanotubes with a matchstick morphology. The metal composition (Ni/Fe ratio) and the carbon supply have no influence on the nanofilament type but strongly affect the nanotube yield. The synthesis temperature induces important changes on both the nanofilament type and yield, which are correlated with important transformations of the catalyst layer in terms of composition, particle size, and physical state.
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http://dx.doi.org/10.1021/jp046619v | DOI Listing |
Doping strategies have been recognized as effective approaches for developing cost-effective and durable catalysts with enhanced reactivity and selectivity in the electrochemical synthesis of value-added compounds directly from CO. However, the reaction mechanism and the specific roles of heteroatom doping, such as N doping, in advancing the CO reduction reaction are still controversial due to the lack of precise control of catalyst surface microenvironments. In this study, we investigated the effects of N doping on the performances for electrochemically converting CO to CO over Ni@NCNT/graphene hybrid structured catalysts (Ni@NCNT/Gr).
View Article and Find Full Text PDFRSC Adv
January 2025
School of Material Science and Engineering, Nanjing Tech University P. R China.
Water pollution, oxidative stress and the emergence of multidrug-resistant bacterial strains are significant global threats that require urgent attention to protect human health. Nanocomposites that combine multiple metal oxides with carbon-based materials have garnered significant attention due to their synergistic physicochemical properties and versatile applications in both environmental and biomedical fields. In this context, the present study was aimed at synthesizing a ternary metal-oxide nanocomposite consisting of silver oxide, copper oxide, and zinc oxide (ACZ-NC), along with a multi-walled carbon nanotubes modified ternary metal-oxide nanocomposite (MWCNTs@ACZ-NC).
View Article and Find Full Text PDFThis paper explores the process of forming arrays of vertically oriented carbon nanotubes (CNTs) localized on metal electrodes using thin porous anodic alumina (PAA) on a solid substrate. On a silicon substrate, a titanium film served as the electrode layer, and an aluminium film served as the base layer in the initial film structure. A PAA template was formed from the Al film using two-step electrochemical anodizing.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong 999077, P. R. China.
Fe-N-C materials are emerging catalysts for replacing precious platinum in the oxygen reduction reaction (ORR) for renewable energy conversion. However, their potential is hindered by sluggish ORR kinetics, leading to a high overpotential and impeding efficient energy conversion. Using iron phthalocyanine (FePc) as a model catalyst, we elucidate how the local strain can enhance the ORR performance of Fe-N-Cs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute of Advanced Materials and Systems, Sookmyung Women's University, Seoul 04310, Republic of Korea.
Multivalued logic (MVL) systems, in which data are processed with more than two logic values, are considered a viable solution for achieving superior processing efficiency with higher data density and less complicated system complexity without further scaling challenges. Such MVL systems have been conceptually realized by using negative transconductance (NTC) devices whose channels consist of van der Waals (vdW) heterojunctions of low-dimensional semiconductors; however, their circuit operations have not been quite ideal for driving multiple stages in real circuit applications due to reasons such as a reduced output swing and poorly defined logic states. Herein, we demonstrate ternary inverter circuits with near rail-to-rail swing and three distinct logic states by employing vdW p-n heterojunctions of single-walled carbon nanotubes (SWCNT) and MoS where the SWCNT layer completely covers the MoS layer.
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