Molecular layer deposition (MLD) is a processing technology for depositing ultrathin polymer or inorganic-organic hybrid films. It is a subset of atomic layer deposition (ALD) and has attracted tremendous attention because of its self-limiting nature, excellent conformality, chemical selectivity and low reaction temperature. [1][2][3][4][5][6] However, because of factors like low vapor pressure and thermal sensitivity of many organic molecules and poor understanding of vapor-phase organic coupling reactions, [7] the variety of combinations of organic and inorganic reactants that have been used for successful MLD is sparse. Up to now, only a few organic-inorganic polymer films, including alucone, [8][9][10][11] zincone, [12] and titanicone, [13,14] have been grown through MLD and those were mainly based on reactions between metal alkyl/chloride and glycol/glycerol. Given the great promise of MLD, it is highly demanded to develop new processing strategies for MLD.One important aspect for producing a larger range of organic-inorganic mixtures is the variability of compositions of the constituting organic and inorganic fractions of the resulting films. A limitation to rather short organic spacers, such as glycol, between the metal ions is a bottleneck for the synthesis of films with a broader range of organic-inorganic volume ratios. By designing new processing strategies for the organic component, the properties of the resulting films can be more easily tuned by varying their composition. These organic-inorganic hybrid films can be further used to produce porous metal oxide films by removing the organic component and the porosity of the resulting inorganic films will depend on the volume occupied by the organic constituting part, making such films attractive for many applications such as catalysis, separation, sensing, and energy conversion and storage.As an important semiconductor, TiO 2 has been intensely investigated using various ALD processes for its evident application potential in solar-energy devices, environmental remediation, and as catalyst support. [15][16][17][18][19][20] However, due to the ALD growth characteristics these TiO 2 films are intrinsically pinhole-free with low specific surface areas, resulting in low photocatalytic activity. [19,20] Recently, the research groups of George, Yerushalmi, and our group reported nearly in parallel the successful preparation of porous TiO 2 by annealing or UV exposure of Ti-containing hybrid organic-inorganic films (titanicones) produced by MLD using TiCl 4 and glycol or glycerol as reactants. [13,14,21] However, their activity is only efficient with ultraviolet light irradiation because of the wide band gap of TiO 2 (3.2 eV for anatase). Therefore, developing new MLD processes to grow porous TiO 2 films with visible light response and larger surface area is very welcome for such applications.Herein, we demonstrate a novel MLD process for preparing porous N-doped TiO 2 films. The process is based on a new strategy, a four-step ABCB reaction sequence using titan...
Nickel oxide (NiO) is a promising electrode material for supercapacitors because of its low cost and high theoretical specific capacitance of 2573 F g(-1). However, the low electronic conductivity and poor cycling stability of NiO limit its practical applications. To overcome these limitations, an efficient atomic layer deposition (ALD) method is demonstrated here for the fabrication of NiO/nanoporous graphene (NG) composites as electrode materials for supercapacitors. ALD allows uniform deposition of NiO nanoparticles with controlled sizes on the surface of NG, thus offering a novel route to design NiO/NG composites for supercapacitor applications with high surface areas and greatly improved electrical conductivity and cycle stability. Electrochemical measurements reveal that the NiO/NG composites obtained by ALD exhibited excellent specific capacitance of up to ∼ 1005.8 F g(-1) per mass of the composite electrode (the specific capacitance value is up to ∼ 1897.1 F g(-1) based on the active mass of NiO), and stable performance after 1500 cycles. Furthermore, electrochemical performance of the NiO/NG composites is found to strongly depend on the size of NiO nanoparticles.
The graphite//5,7,12,14-pentacenetetrone organic dual-ion batteries display two well-defined discharge plateaus at 2.4 and 1.8 V, and a high capacity retention of 92.2% after 100 cycles.
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.