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Optoelectronic memristors have garnered significant attention for their critical applications in neuromorphic computing. The incorporation of materials with excellent absorption efficiency in the fabrication of photoelectric memristors can significantly enhance the image recognition capabilities. CdS nanorods (NRs) are semiconductors with strong UV light absorption that can effectively improve charge transport characteristics, reduce the loss caused by recombination at the crystal surface, and enhance the light absorption characteristics. In this work, an efficient hot injection method for controlling the growth of CdS NRs or nanosquares (NSs) by optimizing the proportion of dodecanethiol (DDT) is reported. Meanwhile, two-terminal optoelectronic memristors based on CdS NSs and CdS NRs are fabricated in which the conductance of the devices can be continuously modulated under electrical and optical stimulations of different widths/spacings/amplitudes. These advantages impart the device with exceptional electrical and optical synaptic functions including excitability, inhibition, paired-pulse facilitation, short-term/long-term plasticity, and memory-forgetting behavior. In addition, the enhancement of the image recognition efficiency of the device by CdS NRs is demonstrated in experiments with the recognition of the optical image "F". This work offers valuable insights for material selection in the development of future neuromorphic devices. [ABSTRACT FROM AUTHOR]

Microorganism-based biosynthesis of quantum dots is a low-cost and green production method with a wide range of potential applications. The development of environmentally friendly synthesis methods is required due to the toxicity and severe reactions that occur during the chemical synthesis of quantum dots. In this study, a novel strain, QD4, with the ability to the effectively and rapidly biosynthesize CdS quantum dots, is isolated and reported. The isolated strain is a Gram-positive, aerobic, flagellated, and rod-shaped bacterium, isolated from seawater. Through the physio-biochemical characterization and 16S rRNA-based phylogenetic tree analysis, the strain is identified as Lysinibacillus boronitolerans QD4. The strain QD4 grows well in the range of 25–40 °C (optimum, 37 °C), pH 5.0–9.0 (optimum, pH 7.0), with a high cadmium-resistance as it could grow at Cd2+ concentration up to 2 mM, implying its good adaptability to the environment and potential for application. Cd2+ and L-cysteine are used as substrates for the biosynthesis of CdS quantum dots by strain QD4. The distinctive yellow fluorescence from CdS quantum dots is visible after only a short induction time (a few hours). Moreover, the properties of the CdS quantum dots are characterized by fluorescence spectroscopy, UV-absorption spectroscopy, TEM, XRD, XPS, and infrared spectroscopy. This study provides a novel strain resource for efficient biosynthesis of extracellular, water-soluble quantum dots, paving potential industrial applications in green production. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen (H₂) generation via solar-powered water splitting represents a sustainable solution to the global energy crisis. Cadmium sulfide (CdS) has emerged as a promising semiconductor photocatalyst due to its tunable bandgap, high physicochemical stability, cost-effectiveness, and widespread availability. This review systematically examines recent advancements in CdS-based heterojunctions, categorized into CdS-metal (Schottky), CdS-semiconductor (p-n, Z-scheme, S-scheme), and CdS-carbon heterojunctions. Various strategies employed to enhance photocatalytic efficiency and stability are discussed, including band structure engineering, surface modification, and the incorporation of crosslinked architectures. A critical evaluation of the underlying photocatalytic mechanisms highlights recent efforts to improve charge separation and photostability under operational conditions. This review highlights the challenges and opportunities in advancing CdS-based photocatalysts and provides a direction for future research. The insights presented aim to accelerate the development of efficient and durable CdS-based photocatalysts for sustainable H₂ production. [Display omitted] • The fundamentals and mechanisms for photocatalytic H 2 evolution were discussed. • The crystal structure, optics, band structure, and synthesis of CdS were outlined. • The design of CdS heterojunctions for enhanced H₂ evolution was emphasized. • Challenges and prospects of developing efficient CdS photocatalysts were proposed. [ABSTRACT FROM AUTHOR]

Recently, ternary metal chalcogenides are widely used as an excellent material for energy generation and environmental remediation. CdIn2S4 (CIS) is a ternary n-type semiconductor acts as an active catalyst because of the presence of the In3+ ions. CdIn2S4 is a highly efficient, low-cost photocatalyst due to its chemical stability, ease of synthesis, high durability, and tunable band gap. CIS photocatalysts gain a lot of attention due to the absorption of superior visible light. Various modifications, such as element doping, co-catalyst deposition, modifications of surface, heterojunction construction enhanced the catalytic performance of CIS. This review describes the applications of CIS and CIS based materials for CO2 reduction, environmental remediation, photocatalytic organic transformations, photoelectrochemical, and H2 production by water spilling. At last, challenges and future perspectives are also provided for further development of CdIn2S4 for energy and environmental applications. [ABSTRACT FROM AUTHOR]

Copper-doped cadmium sulfide quantum dots (Cu-CdS QDs) were used as photocatalysts for the deuteration of halides under visible-light irradiation, with D 2 O as the deuterium source. The combined experimental and theoretical calculation results reveal that long-lived carriers are produced by rapidly capturing photoinduced holes in the Cu-doped energy levels, which is beneficial for improving photocatalytic reactivity. [Display omitted] Deuterium labeling is a highly valuable yet challenging subject of research in various scientific fields. Conventional deuteration methods often involve harsh reaction conditions and suffer from limited reactivity and selectivity. Herein, we report a visible light–driven C–X (X = halogen) to C–D (D = deuterium) exchange strategy over copper-doped cadmium sulfide quantum dots (Cu-CdS QDs) under mild conditions, eliminating the need for noble metal catalysts and expensive deuterium sources. The conversion of aryl halides into deuterated products using Cu-CdS QDs reaches up to 99%, which is four times higher than that achieved using pristine CdS QDs. The substantial enhancement in the photocatalytic activity of the QDs can be primarily attributed to the generation of long-lived charge carriers (approximately 6 μs) induced by Cu doping. Mechanistic studies reveal that the Cu dopants considerably retard the recombination of photoinduced carriers by creating intermediate energy levels that serve as hole trapping centers in CdS QDs, thereby improving the electron utilization efficiency in energetically demanding photoreduction reactions. Additionally, the introduction of Cu increases the energy offset between the conduction band of CdS QDs and molecular acceptors, facilitating the electron transfer process. Upon visible light irradiation, a series of aryl halides can be efficiently converted into the desired deuterated compounds using D 2 O as the deuterium source. This work demonstrates that regulating charge carrier dynamics in ultrasmall QD-based photocatalysts is a promising strategy for promoting organic transformations. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion has emerged as a promising strategy for harnessing renewable solar energy in the valorization of plastic waste. However, research on the photocatalytic transformation of plastics into valuable nitrogen-containing chemicals remains limited. In this study, we present a visible-light-driven pathway for the conversion of polylactic acid (PLA) into alanine under mild conditions. This process is catalyzed by defect-engineered CdS nanocrystals synthesized at room temperature. We observe a distinctive volcano-shaped relationship between sulfur vacancy content in CdS and the corresponding alanine production rate reaching up to 4.95 mmol/g catalyst/h at 70 oC. Ultraviolet-visible, photocurrent, electrochemical impedance, transient absorption, photoluminescence, and Fourier-transform infrared spectroscopy collectively highlight the crucial role of sulfur vacancies. The surface vacancies serve as adsorption sites for lactic acid; however, an excessive number of vacancies can hinder charge transfer efficiency. Sulfur vacancy-rich CdS exhibits high stability with maintained performance and morphology over several runs, effectively converts real-life PLA products and shows potential in the amination of other polyesters. This work not only highlights a facile approach for fabricating defect-engineered catalysts but also presents a sustainable method for upcycling plastic waste into valuable chemicals. Photocatalysis offers a promising pathway to upcycle plastic waste. Here the authors demonstrate how defective cadmium sulfide photocatalysts can convert real-world polylactic acid into the amino acid alanine under visible light. [ABSTRACT FROM AUTHOR]

Lignin-based carbon/cadmium sulfide (LCS) composite photocatalytic materials with excellent porous structures were prepared by simple carbonization and in situ precipitation using lignin from a wide range of sources as a carbon source. The CdS nanoparticles were uniformly fixed in LC, which improved the sunlight absorption ability and good stability of the photocatalyst. The effect of different factors on the pore structure of composite photocatalytic materials was investigated. The results showed that the obtained LCS composites had the maximum specific surface area (334.841 m2·g−1) and porosity (0.4406 mL·g−1) when the mass ratio (the lignin: the templating agent) was 2:1 and the carbonization was carried out at 600 °C for 1.5 h (LCS-600-1.5-2). Compared with pure CdS, the photodegradation performance of the prepared LCS under simulated sunlight (500 W Xe lamp) irradiation was significantly improved. The degradation rate of methylene blue (MB) and methyl orange/methylene blue (MO/MB) by LCS reached 91.7% and 90.8% in 2 h, respectively. The material stability test of LCS showed that LCS has good acid–base stability, and the degradation rate of MB remained above 80% after 5 cycles. The LCS prepared from lignin biomass, improved the dispersion uniformity of cadmium sulfide, reduced the recombination of photogenic electron hole, enhanced the photocatalytic performance under visible light, which greatly expanded the application of photocatalytic material. [ABSTRACT FROM AUTHOR]

As a promising member of the carbon nitride family, nitrogen-rich g-C3N5 has attracted significant attention because of its excellent light absorption performance. Nevertheless, its practical application in photocatalytic CO2 reduction is hindered by severe photogenerated charge recombination and limited CO2 adsorption capacity. Constructing a heterojunction has emerged as an effective strategy to mitigate charge recombination, thereby enhancing the photocatalytic performance of the catalyst. Herein, a series of CdS/g-C3N5-X heterojunction catalysts were prepared via an in situ hydrothermal approach. The obtained heterojunction catalysts exhibited a novel coral reef-like morphology which facilitated the exposure of additional active sites, thereby enhancing the adsorption and activation of CO2. Moreover, studies have shown that CdS can be anchored to the surface of g-C3N5 through C-S bonds, forming a built-in electric field at the interface, which accelerated the separation and transfer of photogenerated charges. Consequently, the resulting heterojunction materials demonstrated high efficiency in photocatalytic CO2 reduction with H2O as a sacrificial agent. In particular, CdS/g-C3N5-0.2 exhibited the maximum photocatalytic performance up to 22.9 μmol·g−1·h−1, which was 6 times and 3 times that of unmodified g-C3N5 and CdS, respectively. The results indicated that the increased active sites and enhanced charge separation of the Cd/g-C3N5-0.2 catalyst were the primary reasons for its improved photocatalytic CO2 reduction performance. This work provides a novel heterojunction-based photocatalyst for efficient CO2 photocatalytic reduction, offering insights into the preparation of high-performance photocatalysts for sustainable energy applications. [ABSTRACT FROM AUTHOR]

Using chemical bath deposition (CBD) methods and various molarities, nanostructured CdS thin films were developed. XRD assured that these films were cubic polycrystalline, containing larger grains as the solution's concentration of cadmium ions increased. Dislocation density values dropped from 79.32 to 62.90 as a result, nevertheless. Also, the strain is lowered from 30.88 to 27.50. AFM results demonstrate that these films suffer a decrease in the value of average particle size, root mean square, and roughness with the molarity concentration. SEM images show CdS thin films at various molarities (0.10, 0.15, 0.20) M, indicating reduced grain size with increased concentration. The optical characteristics indicate a large band gap decreases from 2.46 eV to 2.34 eV and a high transmittance in the visible portion of the spectrum of more than 97.5%. The Refractive Index value changed from 3.23 to 3.11 as the content of cadmium ions increased. CdS films show p-type behavior, reducing resistance with NO2 gas, influenced by molar concentration. The sensitivity of CdS films to NO2 shows a decrement with increased molar concentrations. [ABSTRACT FROM AUTHOR]

As a potential substitute for antibiotics, cadmium sulfide and zinc oxide nano-particles (CdS and ZnO NPs) were created using laser ablation and a straightforward chemical process, respectively. Target of cadmium sulfide, deionized water, zinc nitrate, and sodium hydroxide were used as precursors. Different characterization techniques were used to characterize the CdS and ZnO NPs. X-ray diffraction was used to confirm that the CdS and ZnO had polycrystalline structures with average crystalline sizes of 54.16 nm and 29.23 nm, respectively. The ZnO particles were densely packed 2D curved nanopetals with a diameter of 51.65 nm, whereas the CdS particles were shown to consist of particle agglomerates with spherical and semi-spherical morphologies with a diameter of 34.53 nm from FE-SEM images. According to AFM, the average grain size of ZnO and CdS was 37.51 nm and 79.64 nm, respectively. The purity of the produced nano-particles was validated by FTIR. ZnO has an estimated energy gap of 4.25 eV and CdS of 2.5 eV. Regarding Gram-positive and Gram-negative bacterial strains and fungal strains, the CdS and ZnO NPs exhibit pertinent anti-microbial sensitivity. Compared to S. epidermidis and Klebsiella, the produced nano-particles were shown to have stronger anti-bacterial activity against S. aureus and E. coli, with a larger zone of inhibition. The Candida, however, recorded a higher value of 39mm. [ABSTRACT FROM AUTHOR]

Challenge of passivating defects to harvest the high‐efficiency emission in semiconductor materials significantly limit their practical applications in solid‐state lighting. Here, a robust strategy is developed through pressure‐synergistic ligand engineering to achieve enhanced emission and remarkable piezochromism in the synthesized cadmium sulfide (CdS) nanocrystals (NCs) that exhibits both band‐edge (BE) emission and strong defect emission. With increasing pressure, the CdS NCs experienced a piezochromism from orange emission to white emission. Note that by introducing additional ligand of cadmium oleate, a marked transition is achieved in emission color from orange to blue–violet with high color purity of 71.4% under high pressure. Furthermore, through the pressure‐enhanced defect passivation with capping ligand, the CdS NCs realized a considerable BE emission enhancement, accompanied by the gradually decreased defect emission. In situ high‐pressure experiments and first‐principles calculations indicate that the interaction between ligand and CdS NCs is indeed enhanced under high pressure, thus facilitating the defects passivation and ultimately leading to the observed piezochromism and emission enhancement. This study endows high pressure as an efficient tool to enhance the surface defect passivation, paving the way for precise control over piezochromism and high‐efficiency emission through materials design. [ABSTRACT FROM AUTHOR]

Antimony selenosulfide (Sb2(S,Se)3) has obtained widespread concern for photovoltaic applications as a light absorber due to superior photoelectric features. Accordingly, various deposition technologies have been developed in recent years, especially hydrothermal deposition method, which has achieved a great success. However, device performances are limited with severe carrier recombination, relating to the quality of absorber and interfaces. Herein, bulk and interface defects are simultaneously suppressed by regulating heterogeneous nucleation kinetics with barium dibromide (BaBr2) introduction. In details, the Br adsorbs and dopes on the polar planes of cadmium sulfide (CdS) buffer layer, promoting the exposure of nonpolar planes of CdS, which facilitates the favorable growth of [hk1]‐Sb2(S,Se)3 films possessing superior crystallinity and small interface defects. Additionally, the Se/S ratio is increased due to the replacement of Se by Br, causing a downshift of the Fermi levels with a benign band alignment and a shallow‐level defect. Moreover, Ba2+ is located at grain boundaries by coordination with S and Se ions, passivating grain boundary defects. Consequently, the efficiency is increased from 7.70 % to 10.12 %. This work opens an avenue towards regulating the heterogeneous nucleation kinetics of Sb2(S,Se)3 film deposited via hydrothermal deposition approach to optimize its crystalline orientation and defect features. [ABSTRACT FROM AUTHOR]

Photocatalytic overall splitting of pure water (H2O) without sacrificial reagent to hydrogen (H2) and oxygen (O2) holds a great potential for achieving carbon neutrality. Herein, by anchoring cobalt sulfide (Co9S8) as cocatalyst and cadmium sulfide (CdS) as light absorber to channel wall of a porous polymer microreactor (PP12), continuous violent H2 and O2 bubbling productions from photocatalytic overall splitting of pure H2O without sacrificial reagent is achieved, with H2 and O2 production rates as high as 4.41 and 2.20 mmol h−1 gcat.−1 respectively. These are significantly enhanced than those in the widely used stirred tank‐type reactor in which no O2 is produced and H2 production rate is only 0.004 mmol h−1 gcat.−1. Besides improved charge separation and interaction of H2O with photocatalyst in PP12, bonding interaction of Co9S8 with PP12 creates abundant catalytic active sites for simultaneous productions of H2 and O2, thus leading to the significantly enhanced H2 and O2 bubbling productions in PP12. This offers a new strategy to enhance photocatalytic overall splitting of pure H2O without sacrificial reagent. [ABSTRACT FROM AUTHOR]

Herein, the 1D Solar Cell Capacitance Simulator software is used to perform numerical analysis of thin‐film solar cells with Cu2ZnSnS4, Cu2BaSnS4, Cu2FeSnS4, and Cu2MnSnS4 absorber layers. The main goal is to investigate the impact of parameters, such as absorber layer thickness, acceptor density, buffer layer, bandgap, and donor density, on the efficiency of these solar cells. The absorber layer investigation entails varying the thickness and the acceptor density to evaluate their influence on the efficiency of the solar cell. A new zinc oxide sulfide (Zn(O,S)) buffer layer is also introduced instead of the conventional cadmium sulfide (CdS) buffer layer. The Zn(O,S) bandgap and its donor density, which are investigated in terms of how they affect the efficiency of the solar cells, have been varied. The optimal values for the thickness of the absorber layer, acceptor density, and the bandgap of the buffer layer are calculated. Subsequently, the donor density is evaluated to find any potential defects that may affect the efficiency of the solar cell. These results confirm that Zn(O,S) can be utilized as a buffer layer. This study concludes that Cu2ZnSnS4, Cu2BaSnS4, and Cu2MnSnS4 absorber layers have superior efficiency in comparison with Cu2FeSnS4. [ABSTRACT FROM AUTHOR]

Cadmium (Cd)-enriched adsorbents wastes possess great environmental risk due to their large-scale accumulation and toxicity in the natural environment. Recycling spent Cd-enriched adsorbents into efficient catalysts for advanced applications could address the environmental issues and attain the carbon neutral goal. Herein, a facile strategy is developed for the first time to reutilize the alkali lignin (AL)-derived biochar (ALB) absorbed with Cd into cadmium sulphide (CdS)/C composite for the efficient methylene blue (MB) removal. The ALB is initially treated with Cd-containing solution, then the recycling ALB samples with adsorbed Cd are converted to the final CdS/C composite using NaS2 as the sulphurizing reagent for vulcanization reaction. The optimal ALB400 demonstrates a high adsorption capacity of 576.0 mg g−1 for Cd removal. Then the converted CdS/C composite shows an efficient MB removal efficiency of 94%. The photodegradation mechanism is mainly attributed to carbon components in the CdS/C composite as electron acceptor promoting the separation of photoelectrons/holes and slowing down the abrasion of CdS particles. The enhanced charge transfer and contact between the carrier and the active site thus improves the removal performance and reusability. This work not only develops a method for removing Cd from wastewater effectively and achieving the waste resource utilization but also further offers a significant guidance to use other kinds of spent heavy metal removal adsorbents for the construction of low-cost and high value-added functional materials. [ABSTRACT FROM AUTHOR]

A novel ternary polycarbazole/cadmium sulfide/hematite iron (III) oxide (PCz/CdS/α‐Fe2O3) nanocomposite was synthesized through in situ chemical polymerization method. The phase structure and morphology of PCz, PCz/CdS, PCz/α‐Fe2O3, and PCz/CdS/α‐Fe2O3 were analyzed using XRD and FESEM techniques. From HR‐TEM study, particle size of PCz/CdS/α‐Fe2O3 nanocomposite was found to be 68.09 nm. The chemical composition and the binding energy of the elements present in PCz/CdS/α‐Fe2O3 nanocomposite were examined through XPS. BET studies revealed the mesoporous nature of PCz/CdS/α‐Fe2O3 with a large surface area (35.51 m2 g−1) compared to PCz/α‐Fe2O3 (21.52 m2 g−1) and PCz/CdS (7.47 m2 g−1) nanocomposites. Cyclic voltammetric studies revealed the highest specific capacitance (634.14 Fg−1) of ternary PCz/CdS/α‐Fe2O3 electrode in KOH electrolyte in comparison to H2SO4 (49.44 Fg−1) and Na2SO4 (79.94 Fg−1) electrolytes at a scan rate of 3 mVs−1. Cyclic stability test indicated a high capacitive retentivity of PCz/CdS/α‐Fe2O3 (97%) electrode than PCz/CdS (90%) and PCz/α‐Fe2O3 (93%) electrodes after completion of 2000 cycles. From EIS, PCz/CdS/α‐Fe2O3 displayed a low ESR value (1.35 Ω) than the binary electrodes; the value increased slightly after the cyclic stability analysis. All these indicate the effectiveness of PCz/CdS/α‐Fe2O3 as a suitable electrode for supercapacitors. [ABSTRACT FROM AUTHOR]

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To encounter the burgeoning energy demands of the future, it is imperative to focus on the progress of innovative and profitable techniques for hydrogen (H2) evolution, coupled with an enriched stability of photocatalysts. In this work, we have effectually prepared CdS, CdS:Ce, and CdS:(Ce, Ga) nanoparticles through a chemical refluxing method at 120 °C. Comprehensive structural analysis confirmed the effectual incorporation of Ce and Ga ions in the place of Cd2+ in a CdS matrix. Morphology analysis indicates that the prepared samples are irregularly shaped nanoparticles. Chemical analysis confirmed that the Ce and Ga ions incorporated in the Cd site occurred with 3+ and 4+ valence states. All the samples were assessed for H2 production through water splitting via artificial solar light irradiation. Amid all the samples, CdS:(Ce, Ga) nanoparticles portrayed a giant H2 evolution efficacy (3012 µmol h−1g−1) in 300 min, which is 13.9 times larger than that of the bar CdS sample. Thus, we firmly propose that CdS:(Ce, Ga) samples are authentic and potent candidates for efficient photocatalytic H2 production in sterile environments. [ABSTRACT FROM AUTHOR]

Providing renewable and inexpensive energy sources via photocatalytic water splitting to produce hydrogen relies on fabrication of efficient and stable photocatalyst. Cadmium sulfide (CdS), a typical metal sulfide semiconductor photocatalyst has witnessed considerable exploration for its narrow band gap, attractive band positions and strong photocatalytic driving force. However, the main challenge is its instability due to photocorrosion. In this review, we explore the latest strategic approach of optimizing the efficiency of CdS-based photocatalysts toward commercialization of hydrogen production via water splitting. The fundamental semiconductor properties of CdS including its synthesis methods are reported. Recent progress and advances in the various approaches for enhancing the efficiency of CdS-based photocatalysts have been discussed. Findings reveal that the efficiency and hydrogen production rate of CdS-based photocatalyst can be significantly improved through heterojunction formation, co-calatyst incorporation, morphology modulation and designing a covering layer etc. Furthermore, employing compounded modification strategies is a surest way to harness the photocatalytic advantages of CdS. Commercial application of photocatalytic hydrogen production is feasible, albeit not economically competitive compared to other methods. Thus, scientific and engineering advancements are required to actualize its economic viability in hydrogen generation. So far, CdS-based photocatalytic hydrogen production reach up to 500 mmolg−1h−1 in a laboratory scale and 1. 88 Lh-1 in an up scaled level. A brief future perspective on photocatalytic hydrogen production using CdS is outlined. • Basic fundamentals of photocatalytic water splitting including Thermodynamics and kinetics of the process were overviewed. • We discussed the photocatalytic properties, synthesis and hydrogen production of CdS. • We discussed the Strategies for improving the efficiency of CdS-based photocatalysts toward up-scaling photocatalytic hydrogen production. • Commercial prospects of CdS-based photocatalysts was highlighted. • Challenges in large scale photocatalytic hydrogen production and future perspectives were outlined. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen evolution using inexhaustible clean solar energy is considered as a promising strategy. In order to build an efficient photocatalytic hydrogen production system to satisfy the demands of practical applications, it is of great significance to design photocatalysts that offer high activity, low cost, and high stability. Herein, a series of cheap CdS/Ni(OH)2 composite photocatalysts were designed and synthesized using the hydrothermal method. The introduction of a Ni(OH)2 cocatalyst multiplied the reactive active site of cadmium sulfide and promoted the transfer of photoinduced electrons in a semiconductor. Therefore, CdS/Ni(OH)2 composites demonstrate significantly better photocatalytic performance, and the hydrogen production rate of an optimal CdS/5%Ni(OH)2 composite is 6.9 times higher than that of blank CdS. Furthermore, the stability test also showed that CdS/Ni(OH)2 had good stability. This study aims to serve as a rewarding reference for the development of high-performance composite photocatalysts. [ABSTRACT FROM AUTHOR]

Traditional circuit board fabrication schemes are not directly applicable to the production of flexible, multi‐material circuits. This article reports a technique, microfluidic directed material patterning, which combines soft microfluidic stamps and low‐temperature solution‐phase deposition to generate multi‐material circuits on flexible, non‐planar polymeric supports. Specifically, metallic and semiconductive traces are combined on commodity plastic films to yield functional photosensitive circuits that can be used in the spectrophotometric detection and concentration measurement of microdroplets on 3D "e‐plates." The photoresistive material cadmium sulfide is used in these circuits because it is suitable for visible light detection and it can be deposited directly from aqueous solutions following established bath deposition procedures. This method can produce colorimetric devices capable of quantifying micromolar concentrations of Allura Red in microdroplets of Kool‐Aid. This technique presents the opportunity for producing single‐use or low‐use disposable/recyclable devices for flexible 3D sensors and detectors following a convenient, low‐waste fabrication scheme. The general capabilities of this approach, in terms of substrate geometry and device layout (e.g., the number, area, and pattern of photoresistive elements), can be applied to the design and manufacture of more intricate, multiplexed devices supportive of advanced and/or specialized functions that go beyond those reported in this initial demonstration. [ABSTRACT FROM AUTHOR]

This work focuses on understanding the defect‐related electronic transport in cadmium sulfide (CdS) thin films, and finds thermal treatment as an efficient tool to tailor its intrinsic defect charge carrier concentration for optimum visible‐light photodetection performance. The radio frequency (RF)‐sputtered CdS thin‐films show a substantial decrease in measured dark‐current by three orders of magnitude (μA to nA) with an increase in substrate deposition temperature (Ts) from room‐temperature (RT) to a maximum of 400 °C. With increase in Ts, the current conduction behavior changes from Ohmic (at RT) to Schottky‐behavior (Ts ≥ 100–400 °C). The decrease in dark‐current and the crossover from Ohmic to Schottky electronic transport behavior, pointed to a decrease in defect‐density charge carrier concentration, with increased Ts. Additionally, post‐deposition thermal annealing of CdS thin films also is found to result in a similar decrease in dark‐current (μA to nA). The photo‐to‐dark‐current ratio of CdS thin‐film visible‐light photodetectors increased by two‐orders of magnitude, and its dynamic response time decreased by an order of magnitude via. thermal engineering. The thermal‐annealing treatment possibly reduced the defect‐related trap‐sites, which enables a reliable and faster photo‐switching response for CdS thin‐film‐based visible‐light photodetectors. [ABSTRACT FROM AUTHOR]

[Display omitted] Tubular Co 9 S 8 /CdS heterostructures have been successfully synthesized by in-situ growing CdS onto Co 9 S 8 nanotubes through a simultaneous immobilization and in-situ reduction strategy. It turned out that the so-obtained heterostructure with Co 9 S 8 /CdS molar ratio of 1/10 can display a broad light absorption edge and especially much enhanced capacity for photocatalytic reduction of Cr(VI) under visible light. The characterization analysis and experimental results suggested that an interfacial electrostatic field between Co 9 S 8 and CdS elements in the heterostructure could be constructed due to their different Fermi levels, allowing for more quantities of highly reductive electrons to participate in the photocatalytic reaction. Therefore, the so-obtained Co 9 S 8 /CdS (1/10) heterostructures could achieve the photocatalytic reduction efficiency of 100% within 20 min, which was more than two and four times larger than that of pristine CdS and Co 9 S 8 , respectively. Moreover, the possible photocatalytic reaction mechanism for reducing Cr(VI) was investigated and found to follow the direct Z-scheme charge transfer pathway. This novel fabrication route for composite photocatalysts with tubular heterostructures could lead to the widespread implementations for the elimination of various harmful pollutants in the process of environmental governance. [ABSTRACT FROM AUTHOR]

Cadmium sulfide (CdS) based heterojunctions, including type‐II, Z‐scheme, and S‐scheme systems emerged as promising materials for augmenting photocatalytic hydrogen (H2) generation from water splitting. This review offers an exclusive highlight of their fundamental principles, synthesis routes, charge transfer mechanisms, and performance properties in improving H2 production. We overview the crucial roles of Type‐II heterojunctions in enhancing charge separation, Z‐scheme heterojunctions in promoting redox potentials to reduce electron‐hole (e−/h+) pairs recombination, and S‐scheme heterojunctions in combining the merits of both type‐II and Z‐scheme frameworks to obtain highly efficient H2 production. The importance of this review is demonstrated by its thorough comparison of these three configurations, presenting valuable insights into their special contributions and capability for augmenting photocatalytic H2 activity. Additionally, key challenges and prospects in the practical applications of CdS‐based heterojunctions are addressed, which provides a comprehensive route for emerging research in achieving sustainable energy goals. [ABSTRACT FROM AUTHOR]

Cd0.4Zn0.6S:r-GO composite thin film semiconductor is prepared by the process of layer by layer deposition of cadmium zinc sulphide (Cd0.4Zn0.6S) and reduced graphene oxide (r-GO) on Si-substrate by DIP-coating technique. In this process, initially, aqueous solution of Cd0.4Zn0.6S is deposited on Si-substrate (Cd0.4Zn0.6S/Si) and baked at 500°C temperature, then, aqueous solution of r-GO is deposited on (Cd0.4Zn0.6S/Si) and baked at the same temperature to fabricate (r-GO/Cd0.4Zn0.6S/Si) composite thin film semiconductors. Structural/electronic/electrical/magnetic properties of (Cd0.4Zn0.6S:r-GO)/Si composite thin film semiconductor is enhanced in the vicinity of interfacial defects, impurities, density of states with exchange of metallic/non-metallic ions (Cd2+/Zn2+)/(S2−, SO32−) along with the incorporation of different O-functional radicals that immigrate from r-GO. It is expected that the Cd0.4Zn0.6S:r-GO composite thin film semiconductor is capable of providing future promising optoelectronic as well as magnetic device-based applications. [ABSTRACT FROM AUTHOR]

In the present work, we present the process of preparing CdS nanostructures based on templating synthesis using chemical deposition (CD) on a SiO2/Si substrate. A 0.7 μm thick silicon dioxide film was thermally prepared on the surface of an n-type conduction Si wafer, followed by the creation of latent ion tracks on the film by irradiating them with swift heavy Xe ions with an energy of 231 MeV and a fluence of 108 cm−2. As a result of etching in hydrofluoric acid solution (4%), pores in the form of truncated cones with different diameters were formed. The filling of the nanopores with cadmium sulfide was carried out via templated synthesis using CD methods on a SiO2 nanopores/Si substrate for 20–40 min. After CdS synthesis, the surfaces of nanoporous SiO2 nanopores/Si were examined using a scanning electron microscope to determine the pore sizes and the degree of pore filling. The crystal structure of the filled silica nanopores was investigated using X-ray diffraction, which showed CdS nanocrystals with an orthorhombic structure with symmetry group 59 Pmmn observed at 2θ angles of 61. 48° and 69.25°. Photoluminescence spectra were recorded at room temperature in the spectral range of 300–800 nm at an excitation wavelength of 240 nm, where emission bands centered around 2.53 eV, 2.45 eV, and 2.37 eV were detected. The study of the CVCs showed that, with increasing forward bias voltage, there was a significant increase in the forward current in the samples with a high degree of occupancy of CdS nanoparticles, which showed the one-way electronic conductivity of CdS/SiO2/Si nanostructures. For the first time, CdS nanostructures with orthorhombic crystal structure were obtained using track templating synthesis, and the density of electronic states was modeled using quantum–chemical calculations. Comparative analysis of experimental and calculated data of nanostructure parameters showed good agreement and are confirmed by the results of other authors. [ABSTRACT FROM AUTHOR]

1T/2H‐MoS2/CdS composite was effectively prepared by a two‐step hydrothermal method, which greatly improved the photocatalytic degradation efficiency of tetracycline hydrochloride and photocatalytic cycle stability compared with pristine 1T/2H‐MoS2. The highest photodegradation efficiency of 70.8% is achieved when the molar ratio of 1T/2H‐MoS2 to cadmium sulfide is 1:4. The capture experiment indicates that hydroxyl radical (⋅OH) and superoxide radical (⋅O2−) play a role in the photocatalytic degradation process. A Z‐type heterojunction may be formed on the 1T/2H‐MoS2/CdS composite based on a series of analyses, which improves the photocatalytic performance effectively via expanding the range of light response and promoting the separation of photogenerated electrons and holes. This work provides an alternative to constructing novel Z‐scheme photocatalysts with high performance in the absence of noble metals. [ABSTRACT FROM AUTHOR]

Little is known about the synthesis of colloidal ternary semiconductor magic-size clusters (MSCs) and quantum dots (QDs) in an aqueous environment. We report here the first synthesis of aqueous-phase CdSeS MSC-380 (displaying sharp optical absorption peaking at ∼ 380 nm) at room temperature and QDs at elevated temperatures. The reaction contains CdCl2·2.5H2O, 3-mercaptopropionic acid (MPA, HS–(CH2)2–COOH), selenourea (SeU, NH2–C(Se)–NH2), and thioacetamide (TAA, CH3–C(S)–NH2). Prior to the nucleation and growth (N/G) of QDs, there are clusters formed at 25 °C. The prenucleation-stage clusters are the precursor compound of CdSeS MSC-380 (PC-380). The PC is relatively transparent in optical absorption; in the presence of a primary amine butylamine (BTA, CH3–(CH2)3–NH2), the PC transforms to absorbing CdSeS MSC-380. At 80 °C, the PC decreases and the N/G of CdSeS QDs appears. The present study paves the way to the aqueous-phase synthesis of ternary CdSeS MSCs and QDs, providing an in-depth understanding of the cluster formation in the prenucleation stage of CdSeS QDs. [ABSTRACT FROM AUTHOR]

A nanocomposite consisting of graphene oxide (GO), cadmium sulfide (CdS), lead sulfide (PbS), and bismuth titanate (BT) was synthesized using the hydrothermal method. The structural and morphological characteristics of the nanocomposites were determined using various techniques. A shift in the x-ray diffraction peak positions of the GO-substituted samples indicates the successful integration of GO into the cadmium sulfide/bismuth titanate (CdS/BT) and lead sulfide/bismuth titanate (PbS/BT) matrices. The UV-visible spectra of the GO-reinforced bismuth Titanate show a decrease in the band gap of the nanocomposites. The presence of peaks at 1616 cm−1 and 954 cm−1 in the Fourier-transform infrared spectroscopy spectra confirms the incorporation of GO into the CdS/BT and PbS/BT samples. The photocatalytic performance of the materials was assessed through water-splitting experiments using methanol as a sacrificial agent. The results indicate that the GO composite with PbS/BT samples achieved the highest hydrogen production yield, measuring 438.21 μmolg−1. [ABSTRACT FROM AUTHOR]

Dual nanocomposites based on metal sulfide nanomaterials with a narrow band gap are favorable candidates for future optoelectronic applications and ionizing ray sensors. This study synthesised novel silver-doped zinc sulfide/cadmium sulfide (ZnS/CdS: Ag) nanocomposites using the cost-effective solvothermal approach. For the first time, the radiation sensitivity of the newly developed nanocomposite was assessed using a 241 Am alpha source and ion beaminduced luminescence (IBIL) measurements. When measured at room temperature, the ZnS/CdS: Ag nanocomposite demonstrated significant light emission in the blue-green spectrum. When exposed to alpha irradiation, the ZnS/CdS: Ag nanocomposite film displayed exceptional sensitivity compared to pure ZnS or CdS films. The FESEM images revealed a uniform distribution of semi-spherical and rod-shaped nanoparticles, with an average particle size of 180 nm for both shapes. The results from XRD and EDX demonstrated distinct peaks corresponding to ZnS, CdS, and associated elements within the nanocomposite. The existence of several functional groups within the nanocomposite was confirmed through Fourier transform infrared spectroscopy. Evaluations revealed that the optical quality of the ZnS/CdS: Ag nanocomposite showed enhancement compared to pure ZnS and CdS. The results suggest that the ZnS/CdS: Ag nanocomposite film holds great promise for applications in optoelectronic devices and detection technologies. [ABSTRACT FROM AUTHOR]

The article discusses the possibility of obtaining functional composite materials with pronounced photocatalytic properties. A hybrid composite material based on nanoscale cadmium sulfide fixed on a matrix of hydroxyapatite obtained by precipitation from solution has been developed. The initial components and synthesized samples were certified using some modern physico-chemical analysis methods: X-ray phase analysis, energy dispersive X-ray analysis, Raman spectroscopy, scanning electron microscopy, the Brunauer-Emmett-Teller method. The functional characteristics of the developed composite material Ca10(PO4)6(OH)2-CdS, in particular, the photocatalytic activity under the action of ultraviolet or visible radiation, are investigated. The efficiency of using the developed composite material as a photocatalyst was evaluated by the rate of oxidation of p-dihydroxybenzene (hydroquinone). Based on experimental data obtained, the values of the constants of the reaction rate of photocatalytic oxidation of hydroquinone and the time of its half-conversion under various conditions (radiation, the presence of a catalyst) are calculated. It is proved that the developed composite material, which is a hydroxyapatite modified with colloidal CdS particles, has pronounced catalytic properties and is a promising material for use as a photocatalyst. A patent application has been filed for the developed composite material.

Solar-powered water splitting is an up-and-coming method for hydrogen production. Still, it faces several challenges, including improving light responsiveness, maximizing utilization of photocatalyst active sites, and effectively utilizing photo-induced carriers to prevent low hydrogen production. In this research, we propose an approach for designing a 2D/2D heterostructure catalyst, the Cd-TCPP(Pt)@CdS, which consists of 2D CdS nanosheets (NSs) and a 2D metal-organic framework (MOF) with Pt active sites (Cd-TCPP(Pt)), aiming to achieve highly efficient visible-light-driven hydrogen evolution. Firstly, CdS NSs exhibit excellent responsiveness to visible light, ensuring robust generation of photo-induced carriers. Secondly, the 2D MOF provides abundant Pt active sites, enhancing electron utilization and reducing the energy barrier for proton reduction. Compared to pure CdS NSs (which demonstrate a hydrogen production activity of 1220 μmol/g/h), the newly designed 2D/2D composite catalyst Cd-TCPP(Pt)@CdS exhibits an activity of 13,434 μmol/g/h, representing an 11-fold increase. Impressively, Cd-TCPP(Pt)@CdS maintains a high activity of 3062 μmol/g/h even under sunlight. Density functional theory (DFT) calculations were employed to investigate the principle of proton reduction. The suitable bandgap of CdS and energy gap of 2D Cd-TCPP(Pt) contribute to their strong interaction and consequently higher efficiency in hydrogen evolution. The Pt-single atom (Pt-SA) also provides sites with low free energy for proton reduction, contributing to improved activity. The photocatalytic performance of Cd-TCPP(Pt)@CdS NSs composites demonstrates a synergistic effect between the 2D inorganic semiconductor and the 2D MOF containing the Pt-site, resulting in enhanced utilization of photo-induced carriers and atoms.

[Display omitted] Approaches that add value to biomass through the use of photoreforming reactions offer great opportunities for the efficient use of renewable resources. Here, we constructed a novel zinc cadmium sulphide/molybdenum dioxide-molybdenum carbide–carbon (Zn x Cd 1-x S-y/MoO 2 -Mo 2 C-C) heterojunction which was applied to photoreforming of biomass-based monosaccharides for hydrogen and lactic acid production. Bandgap engineering effectively modulated the redox capacity of Zn x Cd 1-x S-y and exposed more (101) crystalline surfaces, which improved the lactic acid selectivity. The MoO 2 -Mo 2 C-C (MC) co-catalysts had unique microstructures that increased the light absorption range and the number of active sites of Zn x Cd 1-x S-y. These features effectively promoted the separation and migration of photogenerated carriers, which in turn enhanced the photoreforming activity. The optimised Zn 0.4 Cd 0.6 S-0/MC composites exhibited superior photocatalytic activity with a hydrogen yield of 12.2 mmol/g/h. Conversion of biomass-based monosaccharides was approximately 100 %, where arabinose had the greatest lactic acid selectivity (64.1 %). Active species, including h+, ⋅O 2 −, ⋅OH, and 1O 2 , all favoured lactic acid production, where ⋅O 2 − played a major role in the conversion. This study demonstrates that rational design of photocatalysts can achieve the selective conversion of biomass into high value-added chemicals as well as the generation of clean energy. [ABSTRACT FROM AUTHOR]