Cd-O Bond Research Articles

Activation of Bi2MoO6/Zn0.5Cd0.5S charge transfer through interface chemical bonds and surface defects for photothermal catalytic CO2 reduction

The photocatalytic reduction of CO2 to high-value fuels has been proposed as a solution to the energy crisis caused by the depletion of energy resources. Despite significant advancements in photocatalytic CO2 reduction catalyst development, there are still limitations such as poor CO2 adsorption/activation and low charge transfer efficiency. In this study, we employed a defect-induced heterojunction strategy to construct atomic-level interface Cd-O bonds and form Bi2MoO6/Zn0.5Cd0.5S heterojunctions. The sulfur vacancies (VS) formed in Bi2MoO6/Zn0.5Cd0.5S acted as activation sites for CO2 adsorption. While the interfacial stability provided by the Cd-O bonds served as an electron transfer channel that facilitated the movement of electrons from the interface to the catalytic site. The VS and Cd-O bonds simultaneously influence the distribution of charge, inducing the creation of an interface electric field that facilitates the upward displacement of the center of the d-band. This enhances the adsorption of reaction intermediates. The optimized Bi2MoO6/Zn0.5Cd0.5S heterostructure exhibited high selectivity and stability of photoelectrochemical properties for CO, generating 42.97 μmol⋅g−1⋅h−1 of CO, which was 16.65-fold higher than Zn0.5Cd0.5S under visible light drive. This research provides valuable insights for designing photocatalyst interfaces with improved CO2 adsorption conversion efficiency.

Unveiling the Versatile Realm of CdSnO3 Nanoparticles for Advanced Sensing Applications

This study presents the synthesis and characterization of CdSnO3 thin films at different deposition temperatures 400, 500 and 600 °C. The prepared samples were characterized by XRD, FTIR, SEM, EDAX, TEM, optical and ammonia gas sensing properties respectively. X-ray diffraction confirms the orthorhombic crystal structure, with prominent peaks corresponding to the (111), (112), (103), (130), and (133) planes. The mean crystallite size is determined to be 84 nm. Scanning electron microscopy reveals morphological changes with varying substrate temperatures. Energy-dispersive X-ray spectroscopy shows elemental composition variations, highlighting non-stoichiometric CdSnO3 thin films. Transmission electron microscopy images depict larger spherical thin films with clear lattice fringes. Fourier-transform infrared spectra confirm the presence of Cd-O and Sn-O bonds. Optical properties yield a calculated band gap was decreased with increase in temperature. Gas sensing tests demonstrate significant sensitivity to ammonia gas concentrations, with responses affected by ammonia concentrations. Overall, CdSnO3 thin films show promise for applications in diverse fields due to their tunable properties and potential for tailored performance.

Synthesis and FTIR Analysis of Cd Doped Nano Ni - Aluminates

Nano Ni – Aluminates (Ni0.5 Fe0.5 Al2O4) and Cd Doped Nano Ni – Aluminates (Ni0.5 Fe0.5 Al2-x CdxO4) where x = 0.2, 0.4, 0.6 and 0.8 were synthesized by co-precipitation method. Ammonium hydroxide was used as precipitating agent. The samples were characterized using Fourier transform infrared spectroscopy. FTIR spectrum for each unannealed sample of Ni0.5 Fe0.5 Al2 O4 and Ni0.5 Fe0.5 Al2-x Cdx O4 exhibit a broad band near 3450 cm-1 due to –OH stretching vibration of free hydrogen bonded hydroxyl group and a second typical absorption band at 1620 cm-1 resulting from deformative vibration of water molecules. Spectra for samples after annealing show peaks in the range of 900-450 cm-1 and 850-500 cm-1 showing presence of Al-O and Ni-O bonds respectively thus confirm the formation of metal oxides bonds while no peak was observed for –OH bond. A peak around 420 cm-1 is assigned to Cd-O bond.

High-Pressure-Stabilized Post-Spinel Phase of CdFe2O4 with Distinct Magnetism from Its Ambient-Pressure Spinel Phase.

α-CdFe2O4 stabilizes its normal spinel structure due to the covalent Cd-O bond, in which all the connections between adjacent FeO6 octahedral are edge-shared, forming a typical geometrically frustrated Fe3+ magnetic lattice. As the high-pressure methods were utilized, the post-spinel phase β-CdFe2O4 with a CaFe2O4-type structure was synthesized at 8 GPa and 1373 K. The new polymorph has an orthorhombic structure with the space group Pnma and an 11.5% higher density than that of its normal spinel polymorph (α-CdFe2O4) synthesized at ambient conditions. The edge-shared FeO6 octahedra form zigzag S = 5/2 spin ladders along the b-axis dominating its low-dimensional magnetic properties at high temperatures and a long-range antiferromagnetic ordering with a high Néel temperature of TN1 = 350 K. Further, the rearrangement of magnetic ordering was found to occur around TN2 = 265 K, below which the competition of two phases or several couplings induce complex antiferromagnetic behaviors.

Construct a novel CoAl-LDH/CdSe S scheme heterojunction with enhanced charge separation for efficient photocatalytic hydrogen evolution

BackgroundCdSe has emerged as a promising candidate for photocatalytic hydrogen evolution (PHE). To improve its photocatalytic activity, a novel CoAl-LDH/CdSe (CLCSe) heterojunction photocatalyst was designed. MethodsThe CoAl-LDH/CdSe heterojunction photocatalyst was successfully prepared by a facile hydrothermal method. X-ray photoelectron spectra (XPS) proved that CoAl-LDH was combined with CdSe through Cd-O bonds. Scanning electron microscope (SEM) and transmission electron microscope (TEM) collectively uncovered that CoAl-LDH was like sheet structures and CdSe presented irregular cluster particles. Photoluminescence (PL) spectroscopy and electrochemical experiments confirmed that CoAl-LDH/CdSe heterojunction effectively elevated the separation efficiency of charge carriers. Significant FindingsThe electron transfer path of CoAl-LDH/CdSe composites followed the S scheme mechanism. Moreover, the introduction of CoAl-LDH reduced the surface overpotential of CoAl-LDH/CdSe composites. The H2 generation rate of the optimal sample achieved 602 μmol g−1h−1, which was about 12 times that of pure CdSe. Its superior photocatalytic performance could be attributed to the promoted charge separation and decreased overpotential. This work furnishes an innovative assumption for modification of CdSe-based photocatalyst to obtain excellent hydrogen evolution activity.

Remediation of cadmium-contaminated soil by micro-nano nitrogen-doped biochar and its mechanisms.

Cadmium-contaminated soils are an urgent problem that needs to be solved in many countries and regions. In this study, a new heavy metal passivator, micro-nano nitrogen-doped biochar (Nm-NBC), was prepared by introducing nitrogen into biochar. Soybean was used as an experimental plant to compare the effects of corn straw biochar (CBC, not modified), ammonium chloride modified corn straw biochar (NBC), and micro-nano nitrogen-doped biochar (Nm-NBC) on the remediation of Cdcontaminated soil. The results showed that the biomass of soybean, pH, organic matter, and total nitrogen content of the Cd-contaminated soil significantly increased, and the available Cd in soil significantly reduced (P < 0.05) when CBC, NBC, and Nm-NBC were added. The effect was as follows: Nm-NBC > NBC > CBC; Nm-NBC had the best result. When 1% Nm-NBC added to the soil, the Cd content in beans reduced by 68.09%. BET, FTIR, XPS, and SEM were used to analyze the characteristics of Nm-NBC and its mechanisms in the remediation of Cd-contaminated soils. The results showed that Nm-NBC had larger specific surface area and abundant functional groups; -COOH and graphitic nitrogen in Nm-NBC can form Cd-O bond and Cd-π with Cd(II) in the soil. Therefore, Nm-NBC prepared by introducing nitrogen into biochar has a promising application in the remediation of Cd-contaminated soil.

Adsorption of Pb(II) and Cd(II) hydrates via inexpensive limonitic laterite: Adsorption characteristics and mechanisms

Industrial heavy metal pollution has been a long-standing concern, and adsorption is an economical and effective measure for treating wastewater containing heavy metal ions. With its low price, large specific surface area, and high surface activity, limonitic laterite is an ideal low-cost adsorbent for the removal of heavy metal ions. In this paper, the adsorption behavior of heavy metal ions on limonitic laterite was studied, and then the mechanism of Pb2+ and Cd2+ hydrate adsorption was described in detail by combining density functional theory (DFT) calculations. The results showed that the removal ratios of Pb2+ and Cd2+ by laterite were 99.1 % and 86.17 %, respectively, which were much higher than the removal efficiencies of Pb2+ and Cd2+ by synthetic goethite. Furthermore, according to isothermal adsorption and kinetic analysis, Pb2+ and Cd2+ were chemically adsorbed on laterite as a single molecular layer. Further mechanistic analysis from DFT indicated that Pb2+ hydrate exhibits bidentate adsorption on the goethite (010) surface, while the Cd2+ hydrate displays monodentate adsorption. Partial density of states (PDOS) and differential charge density analyses indicate that the Pb6d orbital hybridizes with the O1s orbital and the Pb6s orbital with the O2p orbital, forming the Pb-O bond. The Cd5s orbital hybridizes with the O2p orbital, forming the Cd-O bond. Both Pb2+ and Cd2+ undergo stable chemical absorption on the goethite (010) surface.

Tailoring Hybrid Aluminoborate Frameworks by Incorporating Multicomponent Cadmium-Amine Complexes with Various Conformations.

Inorganic-organic hybrid aluminoborates represent a subclass of porous materials, which rely on effective construction method and structure-directing agents. Herein, we prepared a series of hybrid aluminoborates through covalent decoration of unsaturated Cd2+ complexes, whose formation take advantage of chelating amine and long-chain diamine as mixed ligands. These isolated compounds, that is, [Cd(en)(1,4-dab)0.5][AlB5O10] (1a; its analogue with discrete complex [Cd(en)(dien)H2O][AlB5O10] is denoted as 1b), [Cd(1,2-dap)1.5(1,4-dabH)0.5]{Al[B5O8(OH)2](B5O10)0.5} (2), and [Cd(en)(1,3-dap)][AlB5O10] (3) feature open frameworks (1a, 1b, and 3) or a sandwich-like porous layer (2) that are constructed by AlO4 tetrahedra and [B5O10]5-/[B5O8(OH)2]3- clusters. However, they exhibit different structural features in interconnection, channel environment, and topology as a result of diversified interactions between unsaturated complexes and aluminoborate frameworks, that is, through forming two Cd-O bonds with (i) a pair of neighboring BO3 and AlO4, (ii) the same AlO4, or (iii) the same BO3. The variation in connection mode exerts essential influence on binding effects and steric hindrance that are reflected by changes in interatomic distance, bond angle, window configuration, and interlinkage of units. In addition, the incorporation of unsaturated Cd2+ complexes endows these aluminoborate materials with photoluminescence function. Compound 3 with a noncentrosymmetric structure exhibits second harmonic generation (SHG) response approximately 0.7 times that of KDP. The preparation strategy for hybrid aluminoborates proposed here combines well molecular design with templating assembly, whose synergistic effect would be crucial for drawing a rational pathway for inorganic synthesis, especially with focus on structural and functional innovation.

Optical and charge transfer properties of a new cadmium based metal-organic-framework material

The structural and optical properties of a new Cd-based Metal-Organic-Framework are presented. The structure consists of isolated hybrid clusters formed by CdCl4O2 octahedra linked covalently to two aminocoumarin groups via ligand to metal Cd-O bonds. The optical UV-Visible absorption (OA) shows features related to Ligand to Ligand Charge Transfer (LLCT) and Halogen to Ligand Charge Transfer (XLCT). DFT and TDDFT calculations offered significant results and helped in better validate the experimental observations. The Photoluminescence (PL) and Photoluminescence Excitation (PLE) spectra show an intense and broad band around 401 nm associated also to XLCT. The temperature dependence of the photoluminescence has been also carried out. It revealed two stretching vibrational modes causing the thermal quenching of the PL intensity at low and higher temperature.

Antimicrobial and anticancer activities of Sesbania grandiflora mediated Cadmium oxide nanoparticles

ABSTRACT Cadmium oxide (CdO) nanoparticles have been biosynthesized via Sesbania grandiflora leaf extract and characterized using different analytical techniques. XRD analysis indicated FCC structure with average crystallite size being 45.77 nm. Morphological analyses involving SEM and HR-TEM confirmed the cubic crystalline nature of the prepared samples. The presence of Cd-O bond was ascertained using FTIR technique while the presence of the elements Cd and O was ensured using SEM-EDS. The synthesized CdO nanoparticles have exhibited good Antibacterial activity against both gram positive and gram negative bacteria. In the case of Antifungal studies, Aspergillus niger showed maimum sensitivity as compared to Aspergillus flavus. The bioinspired CdO nanoparticles have shown better Anticancer activity against MCF-7 and HeLa Human cell lines. Therefore, it is concluded that the Sesbania grandiflora leaf extract mediated CdO nanoparticles may serve as a potential candidate for a wide range of biomedical applications.

Synthesis, structural, optical properties and toxicity against cancer cells of new urea-CdCl2 complex

This study deals with the investigation of synthesized (NH2CONH2)CdCl2(Urea-CdCl2) complex properties. X-ray diffraction (XRD) and infrared (IR) measurements are carried out to characterize structural properties. XRD indicates that this compound crystallizes in triclinic system withP1¯space group. IR spectrum proved that the cohesion between the organic and inorganic groups is insured by the CdO bonds. Besides, the optical properties were examined by ultraviolet visible (UV–vis) and photoluminescence (PL) spectroscopies. The Urea-CdCl2 exhibits high absorbance in the UV and good transparency in the visible domain. Besides, Urea-CdCl2 shows a broad bluish emission. Moreover, the toxicity of the Urea-CdCl2 Complex was tested against normal kidney cell line (HEK293) and two cancers cell lines (MDA and T47D). The obtained results showed that Urea-CdCl2 improved the toxicity against the breast cancer line T47D.

Mechanism of novel MoS2-modified biochar composites for removal of cadmium (II) from aqueous solutions.

The purpose of this study was to develop a MoS2-impregnated biochar (MoS2@BC) via hydrothermal reaction for adsorption of cadmium (Cd) from an aqueous solution. The prepared adsorbents were characterized, and their abilities to remove Cd(II) were evaluated. The Langmuir and pseudo-second-order models better described the removal of Cd(II) by MoS2@BC. The prepared MoS2@BC exhibited excellent monolayer adsorption capacity. The S-containing functional groups on MoS2@BC enhanced the adsorption of Cd(II). Multiple Cd(II) sorption mechanisms were identified; including Cd(II)-π interactions, ion exchange, electrostatic interaction, and complexation. The dominant mechanism involved Cd-O (38.3%) bonds and Cd-S complexation (61.7%) on MoS2@BC. The as-prepared MoS2@BC is both economical and efficient, making it an excellent material for environmental Cd(II) remediation.

Novel Fe-Mn binary oxide-biochar as an adsorbent for removing Cd(II) from aqueous solutions

In this study, a pristine biochar (BC) and Fe-Mn binary oxide-biochar (FMBC) were prepared using Pennisetum sp. straw as the feedstock for Cd(II) removal from aqueous solutions. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and specific surface area (SSA) analyses revealed the physico-chemical characteristics of the pristine and designer adsorbents, suggesting that an ultrasonic treatment during synthesis enhanced the SSA and pore volume of the BC, and assisted successful loading of Fe-Mn binary oxide particles on the BC surface. The Cd(II) adsorption data of the adsorbents were fitted to the Langmuir isothermal and pseudo-second-order kinetic models. At a system temperature of 25 °C and pH 5, the maximum Cd(II) adsorption capacities of BC (30.58 mg/g) and FMBC (95.23 mg/g) were obtained. Multiple Cd(II) adsorption mechanisms by FMBC were identified, including precipitation with minerals, complexation with surface functional groups, Cd(II)-π interactions, and cation exchange. As the most dominant adsorption mechanism, Cd-O bonds were formed on the FMBC surfaces precipitating Cd(OH)2 (63.9 wt%) and CdO (36.1 wt%). The FMBC thus could be potentially used as an effective adsorbent for Cd(II) removal from aqueous solutions.

Photocatalytic Performance of SnO2 Coupled CdO Nanoparticles Against MY and RhB Dyes

Precipitation method is adopted to synthesize CdO, SnO2 and CdO-SnO2 nanocomposite. Characterization of the synthesized CdO, SnO2 and CdO-SnO2 composite was done by x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy and photoluminescence (PL) spectroscopy. In the XRD pattern of the composite, cubic CdO and tetragonal SnO2 peaks were observed. The existence of Cd, Sn and O in CdO-SnO2 was confirmed from the XPS spectrum. FTIR spectrum of the composite ascertained the presence of peaks associated with Cd-O and Sn-O bonds. The band gap of pure CdO got blue shifted from 2.49 eV to 2.94 eV when coupled with SnO2. Photodegradation efficiencies of 89.41% and 82.25% were observed by the composite under visible light against metanil yellow (MY) and rhodamine B (RhB) dyes, respectively, which were quite high compared with that of pure CdO and SnO2. Increased life time of carriers due to their effective separation might have enhanced the degradation ability of the composite. The CdO-SnO2 composite catalyst seems to be more stable.

Silver modified cadmium oxide – A novel material for enhanced photodegradation of malachite green

An enhancement of Cadmium oxide (CdO) based catalyst activity was observed on modification with silver (Ag) by hydrothermal route in a short time and at low temperature. The products were characterized by XRD, Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD confirming the formation of CdO showed an intense diffraction peak at 32.73° with lattice plane (111). The IR spectrum shows characteristic peaks at 607, 1387 cm−1 corresponding to Cd-O bonds. Both CdO and Ag modified CdO (Ag-CdO) showed band gaps of 2.76 eV and 2.56 eV respectively stretching into the red portion of the solar spectrum. On irradiation with Ultraviolet (Uv) light CdO-Ag showed 78.02% degradation of malachite green oxalate (MG), a hazardous dye within 175 min in comparison to native CdO (75.85% in 175 min). Photoluminescence (PL) studies demonstrated better emission intensity quenching in case of Ag-CdO which is particularly promising for photocatalytic applications.

CdO[sbnd]Al2O3 – A composite material with enhanced photocatalytic activity against the degradation of MY dye

The present work aims to synthesize CdOAl2O3 nanocomposite and to study its visible light activated photocatalytic performance against metanil yellow dye. Precipitation method was employed to synthesize pure CdO, Al2O3 and CdOAl2O3 nanoparticles. Diffraction peaks related to cubic CdO and monoclinic θ-Al2O3 were observed in the XRD pattern of the composite. XPS spectrum confirmed the presence of Cd, Al and O in the composite. Peaks related to CdO and OAlO bonds were observed from the FTIR spectrum of the composite. Photocatalytic activity confirmed that the CdOAl2O3 nanocomposite exhibits a maximum degradation efficiency of 82.09% against MY dye which was found to be better than pure CdO and Al2O3 nanoparticles due to the synergistic effect, high surface area and the formation of p-n junction at the interface of CdO and Al2O3. The CdOAl2O3 composite catalyst synthesized via precipitation method seems to be more stable and definitely it will be a potential candidate in photocatalysis related field.

Effect of Zn doping on structural, morphological, optical and electrical properties of nebulized spray-deposited CdO thin films

Transparent and conducting pure and Zn-doped CdO thin films (0, 1, 2, 3 and 4 at.% Zn) have been successfully deposited on glass substrates at optimized substrate temperature of 200 °C by spray pyrolysis technique using nebulizer. Structural, morphological, optical and electrical properties of pure and Zn-doped CdO thin films are studied in detail. X-ray diffraction study confirms that all the CdO thin films were polycrystalline in nature with major reflection alone (111) plane having a cubic structure. The high average grain size (345 nm—SEM) and low RMS (6.46 nm—AFM) values are obtained for 3 at.% Zn-doped CdO thin films. The optical band gap energy had increased from 2.49 to 2.57 eV as the function of doping concentration had increased from 1 to 3 at.% Zn and thereafter decreased for higher doping concentration. A strong green emission and slightly shifted for Zn-doping concentration of CdO thin films exhibited by photoluminescence spectra. The CdO bond vibration confirmed by FTIR and Raman analyzes. The resistivity value of un-doped CdO thin film is 1.06 × 10−3 Ω cm and adding Zn-doped concentration, the resistivity consequently decreased to 6.2 × 10−4 Ω cm for 3 at.% Zn-doped CdO thin films and then furthermore increased. A high-quality factor (7.07 × 10−2) was obtained for 3 at.% Zn-doped CdO thin films.

Solid-State Associative Reactions and the Coordination Compression Mechanism.

Coordination polymers and metal-organic frameworks can be modified by high pressure, according to its effects on the radii of central and ligand atoms. The pressure reduces the ligands' radii, and the coordination number is usually increased. Such transformations of the coordination quite generally conform to the inverse rule of pressure and temperature effects, although the temperature-induced transformations are much less frequently observed. The two-dimensional coordination polymer Cd(APP)2NO3·NO3 [APP = 1,4-bis(3-aminopropyl)piperazine] undergoes a pressure-induced isostructural phase transition triggered by a topochemical reaction, yielding Cd(APP)2(NO3)2. The transition retains the symmetry of both phases, and their structures have been determined by X-ray diffraction for the single crystals compressed in a diamond-anvil cell. The reaction increases the Cd coordination, from 6-fold in phase I to 7-fold in phase II, where the new Cd-O bond involves an additional nitrate anion in the Cd coordination sphere.

Characterization of thin fullerene/cadmium telluride films and their stability under x-ray radiation by IR spectroscopy

Thin films based on fullerene with an impurity of cadmium telluride (CdTe) obtained by the methods of thermal evaporation in vacuum are promising for use in organic micro- and opto-electronics. The change in the characteristics of these materials under the influence of various special effects has not been studied in detail. In this study, infrared spectroscopy, scanning electron microscopy, and energy-dispersive microanalysis were used to study thin films of fullerene/cadmium telluride nanocomposites as well as the effect of x-ray irradiation. Thin films containing a composite mixture of fullerene C60 and an inorganic donor CdTe in various ratios were obtained by thermal evaporation in vacuum from a Knudsen cell and by the open-source volume method. The presence of Cd-O and Te-O bonds, oligomerized fullerene states, indicated that the impurity atoms interacted predominantly with oxygen or water vapor. The stability of the nanocomposite films under x-ray irradiation was demonstrated.

Gas sensing and opto-electronic properties of spray deposited cobalt doped CdO thin films

Present work is focused on the improvement of gas sensing and opto-electronic properties of cadmium oxide (CdO) thin films deposited by chemical spray pyrolysis technique, with different cobalt (Co) dopant concentrations in the final spray solution. The XRD patterns reveal that the preferential growth is shifted between (111) and (200) depending on the Co- doping concentrations. The Cd-O bond vibrations were confirmed by micro-Raman analysis. The oxidization state of metal elements was determined by XPS analysis. The FE-SEM analysis revealed the variation in surface microstructure due to the variation in Co- doping concentration in CdO thin films. The elemental composition of deposited films was estimated using EDS. The formaldehyde gas response of 0.50wt% Co- doped CdO thin film was 23%. The electrical properties were estimated by Hall measurements in van der Pauw configuration. The 0.50wt% Co- doped CdO thin film showed a maximum carrier mobility of about 87cm2/Vs and a photocurrent of 2.50nA at 42V. The Co- doped CdO thin films showed a high optical transmittance of about 84% in the range of 600–1100nm. The band gap varies between 2.38eV and 2.50eV. The estimated high figure of merit is 4.79×10−3Ω−1 for 0.50wt% of Co- doped CdO film.