CdS Nanostructures Research Articles

Effect of magnetic field on the structural, optical, and electrical properties of CdS nanoparticles in distilled water by using pulsed laser ablation

In this study, we investigated the impact that the incorporation of a magnetic field has on the properties of cadmium sulfide CdS nanoparticles as well as the performance of an n-CdS/p-Si heterojunction photodetector that was developed by the use of the pulsed laser ablation in a liquid method. Nd:YAG laser pulses (1.064 μm, 550 mJ) were utilized to ablate cadmium sulfide CdS nanoparticles in water. The synthesized nanoparticles were shown to have a polycrystalline hexagonal structure, as evidenced by the findings of the X-ray diffraction experiment, the crystallite size for cadmium sulfide CdS decreased from 4.611 nm to 4.518 nm. The lattice constants of cadmium sulfide CdS nanostructures were determined to be a = 4.1302, c = 6.702, and c/a=1.622. The strain and dislocation density of cadmium sulfide CdS exhibited an increase. Images taken from a field emission scanning electron microscope demonstrated the formation of spherical nanoparticles on the surface. A magnetic field was applied, increasing the CdS film's crystallinity. As a consequence of this enhancement, the particle size of the CdS decreased from 25.18 nm to 12.17 nm. A comparison was made between this and the size of the crystallites that appeared when no magnetic field was present. The EDS spectrum of magnetically prepared cadmium sulfide CdS films indicates the presence of Cd and S, and the weight percentage ratios [Cd]/[S], increase from 3.72 to 3.80. The transmission electron microscopy (TEM) pictures of CdS samples that were generated using a magnetic field contained particles of small size with a mean of 10.10 nanometers. From the FT-IR spectra of cadmium sulfide CdS prepared using a magnetic field within 400–4000 cm−1, the peaks (bands) of cadmium sulfide CdS at 617 cm−1 represent the bending vibration of Cd-S. As a result of the influence of a magnetic field, the optical energy gap of CdS nanoparticles increased from 2.30 eV to 2.72 eV, as indicated by the UV-Vis study. From PL emission spectra the values of the energy band gap of cadmium sulfide CdS increased from 2.45 eV at 505.7 to 2.47 eV when a magnetic field was applied. CdS NP films produced under the influence of a magnetic field were identified as having n-type characteristics by Hall effect assessments, Particle mobility was influenced by particle size. The effect of applying a magnetic field on the efficiency of the n-CdS/p-Si photodetector was investigated and analyzed. When a magnetic field was applied during ablation, the responsivity of n-CdS/p-Si heterojunction photodetectors increased from 0.498 A/W to 0.830 A/W at 510 nm. This was the result of the application of the magnetic field.

Controllable medium layer of ZnS or CdS nanostructures as cocatalyst onto CuO-ZnO heterojunction for enhancing photocatalytic activity

This study explores the construction and performance of CuO-ZnS-ZnO and CuO-CdS-ZnO heterojunction structures on Cu gauze substrates. The assembly process involves three stages: growing CuO nanowires via direct heating, decorating them with ZnS or CdS nanostructures, and growing ZnO nanowires using wet chemical methods. Characterization with FESEM, XRD, FETEM, EDS, and XPS verified the successful preparation of the CuO-CdS-ZnO heterostructures. The photocatalytic activity was evaluated by examining the degradation of rhodamine B (RhB) solution under UVC light exposure. CuO-CdS-ZnO heterostructures with a 5 mM CdS precursor concentration showed superior photocatalytic efficiency compared to CuO-ZnS-ZnO heterostructures. Photoluminescence (PL) spectroscopy indicated more efficient charge separation in CuO-CdS-ZnO, enhancing photocatalytic activity. Experiments with radical scavengers highlighted that hydroxyl and superoxide radicals are the primary reactive species responsible for the degradation of RhB solution. A proposed mechanism highlights the improved electron and hole migration in CuO-CdS-ZnO heterostructures, contributing to their superior performance. Stability tests showed consistent efficiency over multiple cycles, confirming the durability and reusability of these heterostructures. Additionally, CuO-CdS-ZnO heterostructures demonstrated excellent photocatalytic performance under solar light, outperforming CuO-ZnS-ZnO heterostructures. This study underscores the potential of CuO-CdS-ZnO heterostructures for effective and sustainable photocatalytic applications.

Ag–Ag2S–CdS nanostructures: formation, physical characteristics and role in methylene blue removal

Ag–Ag2S–CdS nanostructures: formation, physical characteristics and role in methylene blue removal

Composition-Regulated Photocatalytic Activity of ZnIn2S4@CdS Hybrids for Efficient Dye Degradation and H2O2 Evolution.

Heterostructures of visible light-absorbing semiconductors were prepared through the growth of ZnIn2S4 crystallites in the presence of CdS nanostructures. A variety of hybrid compositions was synthesized. Both reference samples and heterostructured materials were characterized in detail, regarding their morphology, crystalline character, chemical speciation, as well as vibrational properties. The abovementioned physicochemical characterization suggested the absence of doping phenomena, such as the integration of either zinc or indium ions into the CdS lattice. At specific compositions, the growth of the amorphous ZnIn2S4 component was observed through both XRD and Raman analysis. The development of heterojunctions was found to be composition-dependent, as indicated by the simultaneous recording of the Raman profiles of both semiconductors. The optical band gaps of the hybrids range at values between the corresponding band gaps of reference semiconductors. The photocatalytic activity was assessed in both organic dye degradation and hydrogen peroxide evolution. It was observed that the hybrids demonstrating efficient photocatalytic activity in dye degradation were rather poor photocatalysts for hydrogen peroxide evolution. Specifically, the hybrids enriched in the CdS component were shown to act efficiently for hydrogen peroxide evolution, whereas ZnIn2S4-enriched hybrids demonstrated high potential to photodegrade an azo-type organic dye. Furthermore, scavenging experiments suggested the involvement of singlet oxygen in the mechanistic path for dye degradation.

Designing Robust CdS Nanostructures for Superior Photostability and Enhanced Photocatalytic Degradation of Organic Pollutants

AbstractTill date it is a great challenge to synthesize CdS photocatalyst with a high stability. In this study, a stable CdS photocatalyst was successfully synthesized by a simple, cost‐effective hydrothermal route via cadmium acetate and thiourea as Cd and S precursors, respectively. The effect of different processing times (8 h and 24 h) and molar ratios on the photocatalytic activity and stability were mainly investigated. The samples were characterized in detail by XRD, FT‐IR, XPS, UV‐vis DRS, Photolummiscence spectroscopy and Surface photovoltage. The photocatalytic activity of the as‐obtained nanostructures was examined for methylene blue (MB) dye degradation under visible light irradiation (λ≥420 nm). After 70 min of irradiation, nearly 82 % of MB was degraded by CdS nanostructures, display an improved photocatalytic activity for MB degradation with an apparent rate constant (k) of 0.019 min−1. Additionally, CdS nanostructures sustained a good photostability after five consecutive cycles. The higher photocatalytic activity of CdS nanostructure is attributed to an efficient separation of photogenerated electron‐hole pairs stimulated by its optimal molar ratio, optimal temperature and surface morphology. Our synthesized stable nanostructures have potential for dye contaminated waste‐water treatment.

Crystal facet engineering of hollow cadmium sulfide for efficient photocatalytic hydrogen evolution

Metal sulfides have been considered as potential candidates for photocatalytic hydrogen production, but their practical applications are still limited by incident light utilization and charge separation despite the impressive advances in recent decades. To address these challenges, the construction of hollow nanostructure with exposing high active facets offers a desirable pathway for developing novel and high-efficiency photocatalysts. Here, by taking wurtzite CdS as an example, we first develop a general template-assisted cation exchange route for the preparation of hollow CdS nanostructures with diverse exposed facets. The obtained hollow CdS octahedrons with dominant {101} facets exhibit superior photocatalytic H2 evolution rate under visible-light irradiation compared with common CdS nanorods. According to the characterization results and density functional theory calculations, the excellent photocatalytic performance is attributed to the construction of hollow nano-octahedrons with exposed {101} active facets, which facilitates efficient light harvesting and photoinduced charge separation of CdS photocatalyst. The present approach gives a reference to design advanced semiconductors with remarkable photocatalytic activity for realizing efficient solar-to-chemical conversion.

Physical characterizations of Se-doped CdS nanostructures

The investigation thoroughly analyzes undoped and Se-doped CdS nanostructures using multiple techniques. Elemental composition analysis via EDS showed pure Cd and S in the undoped sample, while successful Se incorporation was confirmed in Se-doped samples. XRD revealed distinct CdS phases, with reduced intensity and broadening after Se-doping, indicating lower crystalline quality. The (111) peak shift confirmed Se substitution in the CdS lattice. Williamson-Hall and Monshi-Scherrer analyses demonstrated smaller crystallite sizes and increased lattice strain after Se-doping. FESEM displayed smaller grain sizes after Se-doping. PL analyses showed diminished crystalline quality and reduced intensity. UV–Vis indicated increased absorption and reduced transmission after Se-doping. Bandgap energy declined due to Se-doping and potential CdSe phase formation. Raman spectroscopy confirmed reduced crystalline quality. Se-doping enhances photon absorption, potentially improving optical properties for diverse applications. The study provides a detailed assessment of Se-doped CdS nanostructures, highlighting structural, optical, and morphological changes, valuable for various technological applications.

Influence of functionalized diketopyrrolopyrrole sensitizer on the performance of CdS nanowire based-DSSC applications

Synthesis of chromophore (E)-2-(2-(2-(5-(2,5-bis(2-ethylhexyl)-3,6-dioxo-4-(thiophen-2-yl)-2,3,5,6 tetrahydropyrrolo [3,4-c] pyrrol-1-yl) thiophen-2-yl) vinyl)-4H-chromen-4 ylidene) malononitrile (DPP-CM-CN) has been designed and achieved in multistep reaction strategy. The experimental, photophysical and electrochemical properties along with theoretical calculations were explored. DPP-CM-CN dye was – chemically anchored on CdS nanowires (NWs) to investigate its influence on the dye-sensitized solar cell (DSSC) applications. Under the illumination of standard sunlight conditions, the photovoltaic performance of DPP-CM-CN based CdS nanowire device displayed a power conversion efficiency (PCE) of 0.38 %, which is 3.30 times higher as compared to a bare CdS nanowire (0.115 %) based DSSC device; ascribed to the dye loading time on CdS nanostructures. The present results suggest the potential ability of DPP-CM-CN to enhance DSSC device efficiency and reveal the importance of dye molecules in device fabrication, a key step towards the development of DSSC technology.

Shaping the Future of the Neurotransmitter Sensor: Tailored CdS Nanostructures for State-of-the-Art Self-Powered Photoelectrochemical Devices.

Semiconductor-based photoelectrochemical (PEC) test protocols offer a viable solution for developing efficient individual health monitoring by converting light and chemical energy into electrical signals. However, slow reaction kinetics and electron-hole complexation at the interface limit their practical application. Here, we reported a triple-engineered CdS nanohierarchical structures (CdS NHs) modification scheme including morphology, defective states, and heterogeneous structure to achieve precise monitoring of the neurotransmitter dopamine (DA) in plasma and noninvasive body fluids. By precisely manipulating the Cd-S precursor, we achieved precise control over ternary CdS NHs and obtained well-defined layered self-assembled CdS NHs through a surface carbon treatment. The integration of defect states and the thin carbon layer effectively established carrier directional transfer pathways, thereby enhancing interface reaction sites and improving the conversion efficiency. The CdS NHs microelectrode fabricated demonstrated a remarkable negative response toward DA, thereby enabling the development of a miniature self-powered PEC device for precise quantification in human saliva. Additionally, the utilization of density functional theory calculations elucidated the structural characteristics of DA and the defect state of CdS, thus establishing crucial theoretical groundwork for optimizing the polymerization process of DA. The present study offers a potential engineering approach for developing high energy conversion efficiency PEC semiconductors as well as proposing a novel concept for designing sensitive testing strategies.

Green synthesis of CdS/flaxseed mucilage nanocomposite films using gamma irradiation for packaging applications

Abstract The most common ways to produce nanoparticles are through chemical and physical processes, which can be expensive and environmentally hazardous. Using plant extracts (green synthesis) as reducing and capping agents is a simple, cost-effective, and environmentally friendly method of lowering the usage of dangerous chemicals in the synthesis of metal nanoparticles. This study covers the environmentally friendly synthesis of cadmium sulphide nanoparticles (CdS NPs) using a blend of flaxseed extracts (FM), polyvinyl alcohol (PVA), and chitosan (Cs). The composites are then exposed to gamma irradiation at doses of 20 kGy and 40 kGy. UV–VIS absorption spectroscopy, SEM, HRTEM, EDX, and FTIR were used to analyse the produced nanocomposite films. UV–Vis absorption spectra showed considerable surface Plasmon resonance (SPR) bands at 396–440 nm, indicating that CdS NPs had been successfully synthesized. A progressive red shift in wavelength was noted, along with the broadening of the absorption band as the irradiation dose increased. Transmission electron microscopy pictures revealed that the generated CdS nanostructures were dispersed as spherical nanoparticles with remarkable structural homogeneity. Tensile strength and elongation measurements of the films revealed that the inclusion of CdS NPs improved their mechanical properties. The addition of CdS NPs to the current blends limits biodegradation in soil. Thermal gravimetric analysis findings showed that CdS NPs included in FM/PVA films had improved thermal stability. The antimicrobial activities of the tested films were performed against Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that all of the films exhibited more antibacterial activity against S. aureus than the two others, with the highest activity observed in nanocomposites with a high concentration of CdS.

Sodium Alginate–CdS Nanostructures: Reinforcing Chemoselectivity in Nitro-Organic Reduction and Dye Degradation through Photoinduced Electron Transfer

Sodium Alginate–CdS Nanostructures: Reinforcing Chemoselectivity in Nitro-Organic Reduction and Dye Degradation through Photoinduced Electron Transfer

Morphological regulation of CdS/Ga0.04Cd0.96S nanocomposites for enhanced efficiency of solar-driven rhodamine B degradation

In recent years, semiconductor-based nanocomposites have emerged as promising materials for solar-driven photocatalytic degradation of organic pollutants. In this study, GaxCd1−xS nanospheres were successfully synthesized through the interstitial doping of Ga ions into CdS nanospheres via a hydrothermal route. These nanospheres were further employed to create CdS NRs/Ga0.04Cd0.96S nanocomposites using solvothermal methods, aiming to enhance the efficiency of solar-driven rhodamine B (Rh-B) degradation. The photocatalytic activities of the prepared CdS nanostructures, Ga0.04Cd0.96S nanospheres, and CdSNRs/Ga0.04Cd0.96S nanocomposites were evaluated for dye removal and photocatalytic degradation. Notably, Ga0.04Cd0.96S (1:30) nanospheres exhibited high efficiency in degrading Rh-B compared to pure CdS nanostructures under identical reaction conditions. Single CdS NRs/Ga0.04Cd0.96S (1:1) demonstrated stable cyclic photocatalytic performance over multiple rounds of use. The study further elucidated the enhanced separation and lower recombination of photogenerated electrons and holes in CdS NRs/Ga0.04Cd0.96S compared to Ga0.04Cd0.96S, as confirmed by PL spectrum and photocurrent response studies. The scavenger method was employed to identify reactive species, providing insights into the mechanism of Rh-B degradation. Additionally, the proposed mechanism of photocatalytic degradation of Rh-B over the CdS NRs/Ga0.04Cd0.96S nanocomposites was discussed. This research contributes valuable insights into the development of efficient semiconductor-based nanocomposites for solar-driven photocatalysis, addressing environmental concerns related to organic pollutant degradation.

PVA/CdS-Ag Nanocomposites: Effect of Composition and UV Radiation on Optical, Electrical and Structural Properties

PVA incorporated with different content of CdS-Ag nanostructures are prepared using chemical reduction technique. Along with this these nanocomposites are exposed to UV radiated for different times. The X-ray spectraof PVA /CdS-Ag nanocomposites indicatethe formation of CdS and Ag nanostructures within PVA.Changes in the band structure of nanocomposites with and without UV exposure are studied by UV-Visible spectroscopy. Absorbance and refractive index are noticed to show increment with the concentration of nanostructures and time of exposure. Along with this, the behaviour of different optical parameters such as E0 and Ed is investigated. FE-SEM and EDX analysis exhibit microstructural modification occurring in nanocomposites due to changes in the concentration of incorporated nanostructures and UV radiation. Influence of concentration and UV exposure on conductivity and dielectric parameters on PVA/CdS-Ag nanocomposites are studied.

A photofuel cell-driven self-powered genosensor with a triple-quenching tag of p-Cu2O/Ti3C2Tx for signal amplification

Herein, an ultrasensitive self-powered genosensor is constructed by modifying a model hairpin capture DNA (cDNA) on a nanostructured n-type CdS modified ITO (n-CdS|ITO) photoanode of a photofuel cell. Then, the modified hairpin cDNA is transformed into a single-stranded DNA (ssDNA) by a target DNA (tDNA) and λ-exonuclease. Afterwards, a triple-quenching tag is specially designed by the in situ growth of p-type Cu2O nanoparticles on ultrathin (a few layers) Ti3C2Tx nanosheets to form a p-Cu2O/Ti3C2Tx composite. This is then introduced onto the photoanode surface via strong chelation between the exposed Ti ions on Ti3C2Tx and the ssDNA on n-CdS|ITO. The introduction of p-Cu2O/Ti3C2Tx dramatically decreases the open-circuit voltage (Eocv) of the genosensor and is based on a p-n type semiconductor quenching strategy. This strategy simplifies the complex and expensive aptamer chain design and modification process for the introduction of p-type semiconductors in other biosensing platforms based on a similar quenching mechanism. Meanwhile, both p-Cu2O and Ti3C2Tx exhibit good peroxidase-like catalytic activity, which results in precipitation and steric hindrance on n-CdS|ITO to further quench the output signals. Furthermore, the large Ti3C2Tx nanosheets partially blocked the light absorption of n-CdS. Due to this triple-quenching effect, a wide linear range (1 fM ∼ 100 pM) and a low detection limit (0.230 fM, S/N = 3) are obtained by the genosensor for detecting the tDNA, in this case a biomarker for chronic myelogenous leukemia.

Rapid fabrication of fast response CdS/Si visible light photodetector: Influence of laser energy

In this article, a series of considerably fast response visible light photodetectors-based CdS nanostructure were fabricated via pulsed laser deposition (PLD) technique. Further, a detailed relation between the utilized laser energy during the nanostructured CdS deposition along with the photo-responsive characteristics of the projected devices was established. Particularly, higher laser energy resulted in augmented figure of merit wherein the photo-responsivity (R) increased from 32 to 54.8 mA/W upon increasing the applied laser energy from 140 to 220 mJ, respectively. The linear dynamic range (LDR) of the fabricated devices exhibited a pronounced laser energy linear dependency with maximum value of 20 dB at 220 mJ. In contrast, the optical power profile revealed an inverse correlation with the attained R, descending values from 68.5 mA/W at 6 mW/cm2 to 34.7 mA/W at 26 mW/cm2. Of the fabricated devices, photodetector attained using laser energy of 220 mJ resulted in response/recovery time of 179 and 161 ms, respectively. Despite the consistency and robustness of the proposed geometry, it represents a rapid framework for eco-friendly optoelectronic design.

The realization of the nanoscale bar-codes based on CdS branched nanostructure

The nanostructures with controllable emission colors have shown great attention for achieving high throughput sensing, anti-counterfeiting, and information security. Here, a branched CdS nanostructure with Sn nanoparticles implanted in the junctions is proposed to construct lateral photonic barcodes in a two dimensional domain. Due to the encapsulated Sn nanoparticles, the plasmon enhanced photoluminescence is practically observed. However, with the generation of the high-energy electrons under illumination of the electron beam, the transfer process occurring between the CdS and Sn nanoparticles, result in cathodoluminescence quenching at the junctions. In addition, both temperature coefficients and Debye temperatures of the CdS branched nanostructures are determined to be 5.56 × 10−4 eV/K and 97 K, respectively, based on the temperature dependent photoluminescence spectrum. Also, the emission intensity of the band edge and the defect related emission can be well tuned by the excitation power. As the laser power increases, the emission color changes from red to the green. Therefore, the coding capacity of the CdS branched barcodes can be well modulated by the temperature and pump laser power. Our studies demonstrate the possibility of using these branched nanostructures in multifunctional optical devices.

Enhancing the photocatalytic efficiency of CdS nanostructures by ZnS: A case study on the degradation of methylene blue

Removal of toxic organic industrial dye affluents using solar energy is a sustainable means for overcoming the current energy crisis as well as environmental hazards. CdS nanoparticles are promising photocatalysts due to their energy gap of 2.42 eV and high specific area. Surrounding the CdS core with a shell of ZnS has the potential of reducing the recombination of electron-hole pairs and hence increase its photocatalytic activity. We report here the enhanced photocatalytic activity of CdS/ZnS nanoparticles for the degradation of Methylene blue (MB). The adsorption of MB on the nanoparticles is found to obey pseudo-second-order kinetics.

Review of Recent Developments in the Fabrication of ZnO/CdS Heterostructure Photocatalysts for Degradation of Organic Pollutants and Hydrogen Production.

Researchers have recently paid a lot of attention to semiconductor photocatalysts, especially ZnO-based heterostructures. Due to its availability, robustness, and biocompatibility, ZnO is a widely researched material in the fields of photocatalysis and energy storage. It is also environmentally beneficial. However, the wide bandgap energy and quick recombination of the photoinduced electron-hole pairs of ZnO limit its practical utility. To address these issues, many techniques have been used, such as the doping of metal ions and the creation of binary or ternary composites. Recent studies showed that ZnO/CdS heterostructures outperformed bare ZnO and CdS nanostructures in terms of photocatalytic performance when exposed to visible light. This review largely concentrated on the ZnO/CdS heterostructure production process and its possible applications including the degradation of organic pollutants and hydrogen evaluation. The importance of synthesis techniques such as bandgap engineering and controlled morphology was highlighted. In addition, the prospective uses of ZnO/CdS heterostructures in the realm of photocatalysis and the conceivable photodegradation mechanism were examined. Lastly, ZnO/CdS heterostructures' challenges and prospects for the future have been discussed.

1D/2D CdS/WS2 heterojunction photocatalyst: First-principles insights for hydrogen production

1D/2D CdS/WS2 heterojunctions have been considered to be efficient photocatalysts for visible-light driven hydrolysis; however, the catalytic mechanisms underpinning this behavior remain unclear. Here, a 1D/2D CdS/WS2 heterojunction, with mechanical and thermodynamic stability, was designed and studied by first-principles calculations. The calculated results demonstrate that the CdS/WS2 heterojunction exhibits a typical type-Ⅱ band arrangement. Through the synergistic effect of band offset together with a built-in electric field, photogenerated electrons and holes will each unidirectionally migrate to the conduction band of WS2 and the valence band of CdS, respectively, thereby improving the utilization efficiency for solar energy. This is also indicated by the excellent visible light absorption of the CdS/WS2 heterojunction. Excitingly, the oxidation and reduction potentials of the CdS/WS2 heterojunction not only satisfy the requirements for water splitting, but further have very balanced oxidation and reduction reactions, which guarantees that the redox process can occur more efficiently. The above findings provide theoretical guidance for the design and understanding of efficient heterojunction photocatalysts based on 1D CdS nanostructures.

Fabrication of ZnIn2S4 nanosheets decorated hollow CdS nanostructure for efficient photocatalytic H2-evolution and antibiotic removal performance

Recently, due to the efficient charge transfer and separation, Z-scheme photocatalytic system has attracted much attention and has also been investigated intensively. Herein, Z-scheme ZnIn2S4/CdS hybrid nanostructure (ZIS/CdS) with ZnIn2S4 nanosheets decorated onto hollow CdS nanocubes were successfully prepared. The obtained ZIS/CdS displayed outstanding performance toward photocatalytic reactions such as H2-evolution and antibiotic removal experiment. The generation of heterojunction interfaces and internal electric field (IEF) formed between ZnIn2S4 and CdS could accelerate the charge separation and transfer, which could beneficial to the better mobility of carriers and eventually, improved the photocatalytic activity. We hope this paper could supply an effective protocol for the fabrication and application of hollow sulfide-based nanostructure.