3D Cadmium Research Articles

Hetero-integration of cadmium sulfide nanorod arrays on graphite substrates to guide electron pathways for effective photocatalytic and photoelectrochemical activities

One-dimensional (1D) cadmium sulfide (CdS) nanostructures in photosynthetic systems have attracted attention because of their effective transport pathways for charge extraction which are essential for efficient photocatalytic and photoelectrochemical systems. Despite the numerous benefits of aligned 1D CdS nanostructures in photosynthetic systems, limited attention has been paid to hetero-integrating 1D CdS arrays on substrates with rapid charge extraction capabilities and practical applicability. Herein, we report the fabrication of vertically aligned CdS nanorod arrays on graphite substrates, in which electron transport pathways are rationally designed for effective photocatalysts and photoanodes. Specifically, CdS nanorod arrays integrated on graphite substrates exhibited photocatalytic reactions with excellent reusability and photostability owing to their superior bifacial properties compared to the control free-standing nanostructures. The proposed system also demonstrated excellent photoelectrochemical performance relative to control CdS nanorod arrays integrated on fluorine-doped tin oxide substrates because of the enhanced separation and extraction of photogenerated electrons combined with curvilinear surfaces.

Fabrication of a novel 3D cadmium−organic framework doped with europium as multifunctional fluorescence probes for enhancing detectability

A novel 3D cadmium−organic framework (Cd-MOF) was prepared based on ionothermal synthesis method and successfully doped with Eu3+ cations to obtain Eu@Cd-MOF by postsynthetic modification method. Cd-MOF has a strong and stable framework due to the balance of cations on the overall structure. Using characterization methods such as powder X-ray powder diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetry analysis (TGA), these two materials have excellent solvent and chemical stability. More interestingly, both two materials can be used as multifunctional fluorescent probes to detect Fe3+, Co2+, Cr2O72−, MnO4−, and NB, and exhibit significant sensitivity, anti-interference, and recyclability. It is worth noting that compared to the original Cd-MOF, Eu@Cd-MOF enhanced excellent quenching effect on Fe3+, Co2+, Cr2O72−, MnO4−, and NB. Related to this, we conducted detailed research and discussion on possible fluorescence sensing mechanisms. This work extends propositions to the design and doped with europium of ionothermal synthesis MOFs, and explores their potential applications in the field of fluorescence sensing.

Novel Phenothiazine and Coumarin based Sensitizers: Design, Synthesis and Photoelectrochemical Application by Anchoring on CdS Nanowires

Novel metal-free organic dyes (E)-2-cyano-3-(10-(prop-2-yn-1-yl)-10H-phenothiazin-3-yl)acrylic acid (PPC) and (E)-2-cyano-3-(10-((1-((7-methyl-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-4a,10a-dihydro-10H-phenothiazin-3-yl)acrylic acid (PCTC) was synthesized and then anchored to 1D cadmium sulfide nanowires (1D CdS NWs) for application in photoelectrochemical dye-sensitized solar cell (DSSC). The 1D CdS nanowires were interconnected into a nanonetwork using solution chemistry in a straightforward and efficient manner. The UV-visible spectroscopy, cyclic voltammetry and density functional theory (DFT) were effectively employed to analyze the characteristics of PPC and PCTC. The sensitizer-anchored CdS nanowires have a broader range of light absorption in the UV-visible spectrum compared to bare CdS nanowires. The complete device has the assembly FTO, compact CdS, CdS nanowires, synthesized dye and counter electrode. In photovoltaic assessment, the PCTC and PPC devices yield 3.19 and 3.04 times, respectively, more efficiency than naked CdS nanowires under conventional sunshine illumination (100 mW/cm2, AM 1.5G). The obtained results provide strong evidence supporting the presence of rising external quantum efficiency (EQE) and show a high level of consistency with the optical tests.

2D Cadmium(II) Coordination Polymer Based on 2,5-Furandicarboxylate and 1,4-Bis(1H-imidazol-1-yl)butane Linkers: Synthesis, Characterization and DFT Studies

As a result of hydrothermal synthesis of 2,5-furandicarboxylate (fdc2−), Cd(II) ion and bis(imidazole) derivative 1,4-bis(1H-imidazole-1-yl)butane (bib) ligand, a novel two-dimensional Cd(II) coordination polymer {[Cd(µ-fdc)(H2O)(µ-bib)]·H2O}n (1) was synthesized. According to the results of single crystal X-ray diffraction analysis, the complex was crystallized in the monoclinic system and in the P21/n space group. In addition, the thermal, luminescence and optical properties of the complex were investigated. The complex emits a maximum at 509 nm and also shows semi-conductor properties according to the solid-state UV–Vis diffuse reflection spectra results. To determine chemical structure, vibrational properties and some chemical properties of complex, theoretical calculations were carried out. All theoretical computations were performed using the DFT method at the B3LYP/LanL2DZ level of theory. The obtained experimental results were in good agreement with theoretical results. To calculate HOMO–LUMO energy values, which provided insights into the material's electronic properties, DFT calculations were used. Detailed information about the local and global chemical activity, as well as the electrophilic and nucleophilic nature of the complex, were also obtained.

Synthesis and characterization of four coordination compounds with 3,5-dicarboxy-1-(3-cyanobenzyl)pyridin-1-ium bromide and investigation of the photoreaction of 2D cadmium(II) compound

Four new Cu(II) and Cd(II) coordination compounds, formulated as the {[Cu2(μ-cbpy)2(μ-cbpy)2(H2O)2]⋅2H2O}n (1), {[Cu(μ-cbpy)2]⋅2H2O}n (2), [Cu(cbpy)2(im)2]⋅4H2O (3) and [Cd(μ-cbpy)2(H2O)2]n (4) (H2cbpyBr: 3,5-dicarboxy-1-(3-cyanobenzyl)pyridin-1-ium bromide, im: imidazole) were synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction techniques. Structural analysis indicates that compounds 1, 2 and 4 exhibit 2D layer structures which are are further linked into 3D supramolecular architectures through hydrogen bonding, C−H⋯O, C−N⋯π and π⋯π interactions whereas compound 3 exhibits mononuclear structure. The photoreaction property of compound 4 was investigated and it exhibited color change from pale yellow to dark yellow under 365 nm UV lamp. The thermal properties and phase purities of compounds 1–4 were investigated by thermal analyses (TG, DTA and DTA) and powder X-ray diffraction (PXRD) techniques.

Band Edge Excitons and Amplified Spontaneous Emission of Mercury Chalcogenide Nanoplatelets

AbstractColloidal nanoplatelets of HgSe and HgTe prepared indirectly through cation exchange reactions can transfer many of the advantageous properties of atomically precise, 2D cadmium chalcogenides to the near‐infrared (NIR) spectral window. In this work, HgSe and HgTe nanoplatelets are studied to understand their fundamental photophysical properties, particularly those areas of similarity and difference from cadmium‐based NPLs, and to examine their potential as optical gain media. Similar to cadmium chalcogenide NPLs, low‐temperature photoluminescence of HgTe NPLs displays two‐color emission that depends on temperature, sample, fluence, excitation frequency, and irradiation time. Both HgTe and HgSe show nanosecond emission dynamics at temperatures as low as 2.5 K, with no indication that bright‐dark excitonic splitting governs the low‐temperature photoluminescence. Collectively, experimental data is most consistent with emission from a negative trion state at low temperature. Although the mercury chalcogenide nanoplatelets are shown to have broadened optical resonances compared to the cadmium chalcogenides from which they are derived, they retain slow Auger recombination and can display low‐threshold amplified spontaneous emission in the NIR spectral window. Optical pumping thresholds for HgTe NPLs are observed as low as 4.4 µJ cm−2 and highlight the potential 2D nanoplatelets as gain medium in the near‐infrared.

Fabrication, Crystal Structures, Catalytic, and Anti-Wear Performance of 3D Zinc(II) and Cadmium(II) Coordination Polymers Based on an Ether-Bridged Tetracarboxylate Ligand

Two 3D Zn(II) and Cd(II) coordination polymers, [Zn2(µ4-dppa)(µ-dpe)(µ-H2O)]n·nH2O (1) and [Cd2(µ8-dppa)(µ-dpe)(H2O)]n (2), have been constructed hydrothermally using 4-(3,5-dicarboxyphenoxy)phthalic acid (H4dppa), 1,2-di(4-pyridyl)ethylene (dpe), and zinc or cadmium chlorides. Both compounds feature 3D network structures. Their structure and topology, thermal stability, catalytic, and anti-wear properties were investigated. Particularly, excellent catalytic performance was displayed by zinc(II)-polymer 1 in the Knoevenagel condensation reaction at room temperature.

Spatial charge separated two-dimensional/two-dimensional Cu-In2S3/CdS heterojunction for boosting photocatalytic hydrogen production

Two-dimensional (2D) beta indium sulfide (β-In2S3) shows great potential in photocatalytic hydrogen production due to its broad-spectrum response, relatively negative conduction band edge, high carrier mobility and low toxicity. However, the high charge recombination rate limits the application of In2S3. Here, we in-situ grew 2D cadmium sulfide (CdS) on the surface of In2S3 doped with copper ions (Cu2+) to construct a heterojunction photocatalyst that suppresses charge recombination. The in-situ grown method and shared sulfur composition were conducive to forming the efficient interface contact between In2S3 and CdS, promoting charge transfer and showing the high spatial charge separation rate, resulting in a hydrogen production rate of 868 µmol g-1h−1. The induced Cu2+ extended the light absorption range and stabilized the photocatalyst. By creating stable 2D/2D heterojunction photocatalysts with high charge separation efficiency, this work opens new possibilities for applying In2S3 materials in photocatalytic hydrogen production.

Facile three-step strategy to design CdS@Bi2Se3 core-shell nanostructure: An efficient electrode for supercapacitor application

In this study, we utilized a successive ionic layer adsorption and reaction (SILAR) route to attach bismuth selenide (Bi2Se3) nanoparticles on one dimensional (1D) cadmium sulfide nanowires (CdS NWs) at ambient temperature (27 °C) to design CdS@Bi2Se3 core-shell nanostructure towards active electrode for supercapacitor application. To verify and explore the retrieved surface configuration, structural, elemental, compositional, and surface morphological investigations were performed. The designed CdS@Bi2Se3 core-shell nanostructure not only offers the tremendous number of active areas, but also a continuous and quick one directional electron transport channels, demonstrating noticeable electrochemical performance with specific capacitance of 198 F g−1 (aerial capacitance 59.5 mF/cm2) with 80% cyclic retention @ 2000 cycles. Superior electrochemical activity was enhanced through the mutualistic involvement of Na+ ion insertion/extraction via non-stoichiometric bismuth selenide, which was well supported through electrochemical impedance (EIS) studies.

Enhanced hydrogen production through visible light photocatalysis using 2D MoS2/2D CdS composite

This study seeks to enhance the morphological face contact between 2D molybdenum disulfide (MoS2) nanosheets containing 1T and 2H phases (inhomogeneous) and 2D cadmium sulfide (CdS) sheets/flakes for enhanced charge transfer. The sulfides are synthesized by hydrothermal and solvothermal methods, respectively. MoS2/CdS composites (5, 10, 15, 20, 25 wt.% MoS2) are prepared using a physical method. The 2D forms and compositions of both materials are confirmed by FE-SEM imaging, XRD patterns, and XRF semi-quantitative analysis. XRD patterns also reveal the presence of 1T and 2H phases in MoS2 as well as the similar morphological and crystalline structures of the two sulfides. The adsorption of MoS2 onto the CdS surface has minimal intervention of the latter’s lattice structure as indicated by UV-Vis diffuse reflectance spectroscopy. A hydrogen production rate of 1036.1 µmol gcat-1 h-1 is observed using the 15 wt.% MoS2/CdS composite which was 159 times larger than bare CdS, with photocatalytic retention of about 80 % after 15 hours of use.

Flexible Memristor Constructed by 2D Cadmium Phosphorus Trichalcogenide for Artificial Synapse and Logic Operation (Adv. Funct. Mater. 9/2023)

Transition-Metal Phosphorus Trichalcogenide In article number 2211269, Jiahong Wang, Cong Ye, and co-workers report a flexible memristor fabricated utilizing two-dimensional cadmium phosphorus trichalcogenide nanosheets; the synaptic plasticity, including paired-pulse facilitation and spiking timing-dependent plasticity, are further observed. Owing to the linear conductance modulation capacity, the decimal operation is explored.

Flexible Memristor Constructed by 2D Cadmium Phosphorus Trichalcogenide for Artificial Synapse and Logic Operation

AbstractThe development of advanced microelectronics requires new device architecture and multi‐functionality. Low‐dimensional material is considered as a powerful candidate to construct new devices. In this work, a flexible memristor is fabricated utilizing 2D cadmium phosphorus trichalcogenide nanosheets as the functional layer. The memristor exhibits excellent resistive switching performance under different radius and over 103 bending times. The device mechanism is systematically investigated, and the synaptic plasticity including paired‐pulse facilitation and spiking timing‐dependent plasticity are further observed. Furthermore, based on the linearly conductance modulation capacity of the flexible memristor, the applications on decimal operation are explored, that the addition, subtraction, multiplication, and division of decimal calculation are successfully achieved. These results demonstrate the potential of metal phosphorus trichalcogenide in novel flexible neuromorphic devices, which accelerate the application process of neuromorphic computing.

Dual imaging modality of fluorescence and transmission X-rays for gold nanoparticle-injected living mice.

X-ray fluorescence (XRF) imaging for metal nanoparticles (MNPs) is a promising molecular imaging modality that can determine dynamic biodistributions of MNPs. However, it has the limitation that it only provides functional information. In this study, we aim to show the feasibility of acquiring functional and anatomic information on the same platform by demonstrating a dual imaging modality of pinhole XRF and computed tomography (CT) for gold nanoparticle (GNP)-injected living mice. By installing a transmission CT detector in an existing pinhole XRF imaging system using a two-dimensional (2D) cadmium zinc telluride (CZT) gamma camera, XRF and CT images were acquired on the same platform. Due to the optimal X-ray spectra for XRF and CT image acquisition being different, XRF and CT imaging were performed by 140 and 50kV X-rays, respectively. An amount of 40mg GNPs (1.9nm in diameter) suspended in 0.20ml of phosphate-buffered saline were injected into the three BALB/c mice via a tail vein. Then, the kidney and tumor slices of mice were scanned at specific time points within 60min to acquire time-lapse in vivo biodistributions of GNPs. XRF images were directly acquired without image reconstruction using a pinhole collimator and a 2D CZT gamma camera. Subsequently, CT images were acquired by performing CT scans. In order to confirm the validity of the functional information provided by the XRF image, the CT image was fused with the XRF image. After the XRF and CT scan, the mice were euthanized, and major organs (kidneys, tumor, liver, and spleen) were extracted. The ex vivo GNP concentrations of the extracted organs were measured by inductively coupled plasma mass spectrometry (ICP-MS) and L-shell XRF detection system using a silicon drift detector, then compared with the in vivo GNP concentrations measured by the pinhole XRF imaging system. Time-lapse XRF images were directly acquired without rotation and translation of imaging objects within an acquisition time of 2min per slice. Due to the short image acquisition time, the time-lapse in vivo biodistribution of GNPs was acquired in the organs of the mice. CT images were fused with the XRF images and successfully confirmed the validity of the XRF images. The difference in ex vivo GNP concentrations measured by the L-shell XRF detection system and ICP-MS was 0.0005-0.02% by the weight of gold (wt%). Notably, the in vivo and ex vivo GNP concentrations in the kidneys of three mice were comparable with a difference of 0.01-0.08wt%. A dual imaging modality of pinhole XRF and CT imaging system and L-shell XRF detection system were successfully developed. The developed systems are a promising modality for in vivo imaging and ex vivo quantification for preclinical studies using MNPs. In addition, we discussed further improvements for the routine preclinical applications of the systems.

Synthesis of 3D Cadmium(II)-Carboxylate Framework Having Potential for Co-Catalyst Free CO2 Fixation to Cyclic Carbonates

Metal-organic frameworks (MOFs) are porous coordination polymers with interesting structural frameworks, properties, and a wide range of applications. A novel 3D cadmium(II)-carboxylate framework, CdMOF ([Cd2(L)(DMF)(H2O)2]n), was synthesized by the solvothermal method using a tetracarboxylic bridging linker having amide functional moieties. The CdMOF crystal structure exists in the form of a 3D layer structure. Based on the single-crystal X-ray diffraction studies, the supramolecular assembly of CdMOF is explored by Hirshfeld surface analysis. The voids and cavities analysis is performed to check the strength of the crystal packing in CdMOF. The CdMOF followed a multistage thermal degradation pattern in which the solvent molecules escaped around 200 °C and the structural framework remained stable till 230 °C. The main structural framework collapsed (>60 wt.%) into organic volatiles between 400–550 °C. The SEM morphology analyses revealed uniform wedge-shaped rectangular blocks with dimensions of 25–100 μm. The catalytic activity of CdMOF for the solvent and cocatalyst-free cycloaddition of CO2 into epichlorohydrin was successful with 100% selectivity. The current results revealed that this 3D CdMOF is more active than the previously reported CdMOFs and, more interestingly, without using a co-catalyst. The catalyst was easily recovered and reused, having the same performance.

Structural Elucidation and Electrochemiluminescence on a 3D Cadmium(II) MOF with 5-c Topology

A novel cadmium(II) based MOF, [Cd(μ–ppza)]n (1) (H2ppza = 3–(pyridin–4–yl)–1H–pyrazole–5–carboxylic acid) was synthesized under solvothermal condition. The single-crystal X-ray diffraction reveals that the title MOF 1 crystallizes in the triclinic system with the P–1 space group, and each Cd(II) is coordinated with five (Hppza)2− ions forming a distorted octahedron. The carboxylic group in the ligand acts as a bridge linking the Cd(II) ions into a 3D structure. MOF 1 has a 5-c {46.64} topological structure. Furthermore, MOF 1 exhibits good electrochemiluminescence (ECL) behavior.

Syntheses, crystal structures, luminescent sensing and photocatalytic properties of two 2D cadmium(II) coordination polymers constructed from mixed ligands

Two ternary Cd(II) coordination polymers (CPs), namely, [Cd(TDC)(L)]n (1) and {[Cd(TCPA)(L)]·H2O}n (2) (H2TDC = 2,5-thiophenedicarboxylic acid, H2TCPA = 2,3,5,6-tetrabromoterephthalic acid, L = 1,4-bis(thiabendazole-1-yl)-2-butene) were hydrothermally synthesized and characterized. Both CPs display the 2D 63 layer, which are finally extended into 3D supramolecular network by weak hydrogen bond interactions. 1 and 2 possess excellent chemical stability in a wide pH range of 2–13. Both Cd(II) CPs can serve as efficient luminescent probes for the sensing of acetylacetone (acac), Fe(III) ions and norfloxacin (NOR) in water. The photodegradation ability of two CPs for methyl violet under UV irradiation was investigated in detail.

Construction of Z–scheme 1D CdS nanorods/2D ultrathin CeO2 nanosheets toward enhanced photodegradation and hydrogen evolution

The synthesis of semiconductor-based photocatalytic materials has been developed rapidly because of the wide application potential in solving environmental pollution and energy crises. In this study, a noval Z–scheme heterojunction by in situ assembly of two-dimensional (2D) ceria nanosheets and one-dimensional (1D) cadmium sulfide nanorods (CdS/CeO2) was constructed and employed for effective photocatalytic degradation of contaminant and hydrogen production under irradiation. The morphologies and physicochemical properties of as-synthesized nanostructures were analyzed by a series of characterizations. The optimized CdS/CeO2 showed more superior degradation efficiency of tetracycline than the most CdS-based materials as reported, and exhibited about 1.8 folds higher hydrogen evolution efficiency than pristine CdS. A direct Z–scheme charge transfer mechanism was proposed by combining radicals trapping experiments and electron paramagnetic resonance spectra, which accelerated the efficient transport of photo-induced charge carriers. The present work demonstrates that CdS/CeO2 nanomaterial with high photocatalytic performance has a promising application in the environmental treatment and green energy production.

All‐Inorganic CsPbBr3 Perovskite Nanocrystals/2D Non‐Layered Cadmium Sulfide Selenide for High‐Performance Photodetectors by Energy Band Alignment Engineering

AbstractPerovskites have attracted intensive attention as promising materials for the application in various optoelectronic devices due to their large light absorption coefficient, high carrier mobility, and long charge carrier diffusion length. However, the performance of the pure perovskite nanocrystals‐based device is extremely restricted by the limited charge transport capability due to the existence of a large number of the grain boundary between perovskite nanocrystals. To address these issues, a high‐performance photodetector based on all‐inorganic CsPbBr3 perovskite nanocrystals/2D non‐layered cadmium sulfide selenide heterostructure has been demonstrated through energy band engineering with designed typed‐II heterostructure. The photodetector exhibits an ultra‐high light‐to‐dark current ratio of 1.36 × 105, a high responsivity of 2.89 × 102 A W−1, a large detectivity of 1.28 × 1014 Jones, and the response/recovery time of 0.53s/0.62 s. The enhancement of the optoelectronic performance of the heterostructure photodetector is mainly attributed to the efficient charge carrier transfer ability between the all‐inorganic CsPbBr3 perovskites and 2D cadmium sulfide selenide resulting from energy band alignment engineering. The charge carriers’ transfer dynamics and the mechanism of the CsPbBr3 perovskites/2D non‐layered nanosheets interfaces have also been studied by state‐state PL spectra, fluorescence lifetime imaging microscopy, time‐resolved photoluminescence spectroscopy, and Kelvin probe force microscopy measurements.

CdS nanosheets as electrode materials for all pseudocapacitive asymmetric supercapacitors

Metal sulphides have recently been explored as a very promising pseudocapacitor electrode, owing to their unique physical, electronic and electrochemical properties. This study reports the synthesis and pseudocapacitor applications of 2D cadmium sulphide (CdS) nanosheets deposited on Ni foam via electrophoretic deposition method. Comprehensive morphological and electrochemical analyses were performed to elucidate the correlation between the structural features of CdS and their charge storage properties. The single electrode characterizations of CdS could exhibit a specific capacitance as high as 1165 F g–1 at 2 mV s–1. An asymmetric supercapacitor prototype was also fabricated using the CdS nanosheets with ceria–titania nanotube composite (CeO2–TNT) counter electrode. The device could exhibit an energy density as high as 14.58 Wh kg–1 at a power density of 1.9 kW kg–1. At the end of 2000 cycles, the device could retain 100% of its initial capacitance.

NiO Nanosheets Coupled With CdS Nanorods as 2D/1D Heterojunction for Improved Photocatalytic Hydrogen Evolution.

Designing low-cost, environment friendly, and highly active photocatalysts for water splitting is a promising path toward relieving energy issues. Herein, one-dimensional (1D) cadmium sulfide (CdS) nanorods are uniformly anchored onto two-dimensional (2D) NiO nanosheets to achieve enhanced photocatalytic hydrogen evolution. The optimized 2D/1D NiO/CdS photocatalyst exhibits a remarkable boosted hydrogen generation rate of 1,300 μmol h−1 g−1 under visible light, which is more than eight times higher than that of CdS nanorods. Moreover, the resultant 5% NiO/CdS composite displays excellent stability over four cycles for photocatalytic hydrogen production. The significantly enhanced photocatalytic activity of the 2D/1D NiO/CdS heterojunction can be attributed to the efficient separation of photogenerated charge carriers driven from the formation of p-n NiO/CdS heterojunction. This study paves a new way to develop 2D p-type NiO nanosheets-decorated n-type semiconductor photocatalysts for photocatalytic applications.