Publications by authors named "Nithima Khaorapapong"

The catalytic reduction of CO into value-added chemicals has become important in recent years, and a catalyst that is efficient, nontoxic, and inexpensive is highly demanded. In particular, room still exists for exploring mixed-anion compounds as new catalysts. Here, we show that the Zn-based mixed-anion compounds Zn(OH)(NO) and Zn(OH)(NO), which were formed on the surface of AlO using Zn(NO)·6HO as the precursor, can convert CO into HCOOH with >80% selectivity in the presence of a Ru(II) photosensitizer and 1-benzyl-1,4-dihydro-nicotinamide as an electron donor under visible light ( = 460 nm).

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Although hierarchical porous carbon materials have been widely used for electrocatalysis, the role of curvature in carbon nanostructures during electrochemical reactions remains poorly understood due to a lack of experimental models featuring clearly defined curved geometries and periodic structures. In this study, we fabricate hierarchical porous cobalt- and nitrogen-containing carbon nanoplates with trimodal porosity (macro-, meso-, and micropores) and continuous, homogeneous curved edges (Co/N-CNP-CURV) using a polystyrene-directed templating approach. The Co/N-CNP-CURV catalyst exhibits excellent catalytic activity and stability for the alkaline oxygen reduction reaction, with a half-wave potential of 0.

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The formation of copper oxide and zinc oxide mixture in montmorillonite was conducted by the reaction of an aqueous dispersion of Cu/Zn exchanged montmorillonite and an aqueous solution of sodium hydroxide under hydrothermal treatment. The resulting product was characterized by X-ray diffraction, scanning and transmittance electron microscopies, as well as UV-visible and photoluminescence spectroscopies. The diffuse reflectance absorption spectra showed the absorption onsets due to copper oxide (885 nm) and zinc oxide (310 and 580 nm) in the product.

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The interlayer stacking modes of 2D covalent-organic frameworks (COFs) directly influence their structural features, ultimately determining their functional output. However, controllably modulating the interlayer stacking structure in traditional 2D metal-free COFs, based on the same building blocks, remains challenging. Here, two trinuclear copper organic frameworks are synthesized successfully with different interlayer stacking structures: eclipsed AA stacking in Cu-PA-COF-AA and staggered ABC stacking in Cu-PA-COF-ABC, using the same monomers.

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Efficient and durable electrocatalysts fabricated by using nanosized nonprecious-metal-based materials have attracted considerable attention for use in the oxygen evolution reaction (OER). Understanding performance disparities and structure-property relationships of various nonprecious-metal-based nanostructures is crucial for optimizing their applications. Herein, CoP nanoparticles encompassed within a CoFeP shell (named CoP/CoFeP) are fabricated.

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One of the difficulties limiting covalent organic frameworks (COFs) from becoming excellent adsorbents is their stacking/aggregation architectures owing to poor morphology/structure control during the synthesis process. Herein, an inorganic-organic nanoarchitectonics strategy to synthesize the MXene/COF heterostructure (Ti C T /TAPT-TFP) is developed by the assembly of β-ketoenamine-linked COF on the Ti C T MXene nanosheets. The as-prepared Ti C T /TAPT-TFP retains the 2D architecture and high adsorption capacity of MXenes as well as large specific surface area and hierarchical porous structure of COFs.

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The fabrication of zinc sulfide (ZnS) and cadmium sulfide (CdS) hybrids was carried out by the sulfidization of Zn(II) or Cd(II) adsorbed in dodecylsulfate modified CoAl-layered double hydroxide through solid-liquid reaction. The TEM images showed the nanocrystals of ZnS (2.61 nm) or CdS (3.

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Article Synopsis
  • The review focuses on electrocatalysts derived from zeolitic imidazolate frameworks (ZIFs), which show promise for efficient and stable electrochemical energy conversion.
  • It highlights different structural types of ZIF-derived superstructures, including open carbon cages and hollow structures, and examines their importance in creating materials with atomic sites for catalysis.
  • The text also discusses the application of ZIF-derived single-atom sites in processes like CO electroreduction and hydrogen synthesis, along with the challenges faced in improving their performance for energy conversion.
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Thought as raw materials clay minerals are often disregarded in the development of advanced materials. However, clays of natural and synthetic origin constitute excellent platforms for developing nanostructured functional materials for numerous applications. They can be easily assembled to diverse types of nanoparticles provided with magnetic, electronic, photoactive or bioactive properties, allowing to overcome drawbacks of other types of substrates in the design of functional nanoarchitectures.

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The preparation of cadmium selenide nanoparticles in the interlayer space of magadiite, a layered sodium silicate, modified with the cetyltrimethylammonium cation was studied. The preparation was based on the formation of cadmium selenide by the reaction between the cetyltrimethylammonium modified magadiite and an aqueous mixture of cadmium sulfate and sodium selenosulfite at room temperature. The resulting hybrids were characterized by XRD, FT-IR, HRTEM, TG-DTA, as well as UV-visible and photoluminescence spectroscopy.

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The incorporation of metal sulfide mixture, manganese sulfide and zinc sulfide (MnS–ZnS) or manganese sulfide and cadmium sulfide (MnS–CdS), in two types of montmorillonites (sodium montmorillonite and cetyltrimethylammonium modified montmorillonite) was investigated. The hybrids were characterized by powder X-ray diffraction, thermogravimetric-differential thermal analysis, transmission electron microscopy (TEM), and Raman, UV-visible and photoluminescence spectroscopies. The experimental evidences such as the expansion of the interlayer spaces and the presence of the absorption and photoluminescence due to MnS, ZnS and/or CdS revealed that the mixed metal sulfides formed in the interlayer space of montmorillonites.

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Cadmium telluride-titanium dioxide nanocomposite was prepared by hydrothermal reaction of sol-gel derived titanium dioxide and organically modified cadmium telluride. The crystallinity of titanium dioxide in the nanocomposite was higher than that of pure titanium dioxide obtained by the reaction under the same temperature and pressure conditions, showing that cadmium telluride induced the crystallization of titanium dioxide. Diffuse reflectance spectrum of the nanocomposite showed the higher absorption efficiency in the UV-visible region due to band-gap excitation of titanium dioxide.

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Two luminescent hybrids, Znqb- and Znqp-montmorillonites (q = 8-hydroxyquinoline, b = 2,2'-bipyridine, p = 1,10-phenanthroline), were prepared by solid-solid reactions between Zn(II)-montmorillonite and two ligands (8-hydroxyquinoline and 2,2'-bipyridine or 1,10-phenanthroline) at room temperature. The intercalation and in situ complex formation of the two ligands into an interlayer space of Zn(II)-montmorillonite were confirmed by powder XRD, TG-DTA, as well as FT-IR, UV-vis and photoluminescence spectroscopies. The emission band of Znqb-montmorillonite was red-shifted compared to that of the mixture of Znq-montmorillonite and Znb-montmorillonite, confirming the formation of Znqb complex in montmorillonite.

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The immobilization of organically modified cadmium selenide on montmorillonite was investigated by the reaction of modified cadmium selenide nanoparticles with montmorillonite. The intercalation of the nanoparticles was indicated by the expansion of the interlayer space and spectroscopic observations. The diffuse reflectance absorption spectrum of the product showed absorption onset at 567 nm.

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