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Simultaneously optimizing nonlinear absorption coefficient and modulation depth is a considerable challenge for nonlinear optical materials. Here we present an effective solution through constructing PbS2‐based inorganic‐organic superlattice. PbS2/Cn superlattice particles are synthesized, where n (4, 6, and 8) denotes the number of carbon atoms in the organic component. First‐principles simulations indicate the formation of covalent bonds and van der Waals interaction between PbS2 unit and interlayer organic molecules. All samples exhibit strong nonlinear absorption under femtosecond laser excitation with a wavelength range between 515 nm and 900 nm, and the nonlinear absorption coefficient increases with interlayer distance. The optimized sample, PbS2/C8, demonstrates outstanding nonlinear absorption and substantial modulation depth under 800 nm (the third‐order nonlinear absorption coefficient βeff, 10449 ± 609 cm GW−1; modulation depth, 39.1%) and 900 nm (the fifth‐order nonlinear absorption coefficient γeff, 6465 ± 68 cm3 GW−2; modulation depth, 88.1%), which exhibits saturable absorption under 515 nm (βeff, ‐4932 ± 818 cm GW−1; modulation depth, 48.1%). It exhibits a small optical limiting threshold of 1.23 mJ cm−2. These performances surpass those of typical single‐/few‐layer metal chalcogenides. Structural and spectral analyses elucidate that the remarkable optical nonlinearity can be attributed to quantum confinement in the inorganic layer and the dielectric enhancement of the superlattice. [ABSTRACT FROM AUTHOR]

Researchers have created a modern infrared (IR) sensor that is both super-sensitive and highly flexible. This remarkable device possesses impressive properties of exceptional sensitivity (24,000%), high responsiveness (1.25 A/W), and fast response time (3 ms). This innovation stands out for its unique construction: an ultrathin layer of lead sulfide (PbS) deposited on a standard Whatman filter paper. This design achieves a photo-current 32 times greater than previous record-holding PbS thin films. The key advantage is its unmatched flexibility. This sensor can bend and flex without breaking, maintaining its IR detection capabilities even after enduring extreme bending cycles. This breakthrough paves the way for a new era of wearable IR photo sensors, flexible electronics, and medical applications. [ABSTRACT FROM AUTHOR]

Short‐wave infrared (SWIR) photodetectors utilizing quantum dot (QD) material systems, harnessed through the quantum confinement effect to tune the absorption wavelength, offer an attractive avenue for the development of cost‐effective and solution‐processed photodetectors compared to the relatively expensive compound semiconductor photodetectors. However, the pores between the QDs and poor chemical stability after surface modification have impeded the practical application of quantum‐dot‐based photodetectors. In this study, high‐gain SWIR photodetector is demonstrated and achieved by incorporating PbS QD into the Cs2AgBiBr6 halide‐based double perovskite matrix, as confirmed by X‐ray diffraction, transmission electron microscope, and energy dispersive spectrometer. The thin film structure and detailed local structure are revealed by 2D grazing‐incidence wide and small‐angle X‐ray scattering. The resulting PbS@Cs2AgBiBr6‐based SWIR photodetector exhibits remarkable performance with a responsivity and detectivity of 15000 A W−1 and 1.31 × 1012 cm Hz1/2 W−1, respectively. This study offers valuable insights into the design of composite materials for high‐gain SWIR photodetectors. [ABSTRACT FROM AUTHOR]

Multiplexed fluorescence in vivo imaging remains challenging due to the attenuation and scattering of visible and traditional near infrared (NIR‐I, 650–950 nm) wavelengths. Fluorescence imaging using shortwave infrared (SWIR, 1000–1700 nm, a.k.a. NIR‐II) light enables deeper tissue penetration due to reduced tissue scattering as well as minimal background autofluorescence. SWIR‐emitting semiconductor quantum dots (QDs) with tunable emission peaks and optical stability are powerful contrast agents, yet few imaging demonstrations exclusively use SWIR emission beyond two‐color imaging schemes. In this study, we engineered three high quality lead sulfide/cadmium sulfide (PbS/CdS) core/shell QDs with distinct SWIR emission peaks ranging from 1100–1550 nm for simultaneous three‐color imaging in mice. We first use the exceptional photostability of QDs to non‐invasively track lymphatic drainage with longitudinal imaging, highlighting the detailed networks of lymphatic vessels with widefield imaging over a 2 hr period. We then perform multiplexed imaging with all three QDs to distinctly visualize the lymphatic system and spatially overlapping vasculature networks, including clearly distinguishing the liver and spleen. This work establishes optimized SWIR QDs for next generation multiplexed and longitudinal preclinical imaging, unlocking numerous opportunities for preclinical studies of disease progression, drug biodistribution, and cell trafficking dynamics in living organisms. [ABSTRACT FROM AUTHOR]

During pyrite mining, tailings and waste residues are generated, and the oxidation of exposed metal sulfides leads to significant environmental issues such as acid mine drainage pollution. Studying the oxidation mechanism of pyrite is crucial for inhibiting or preventing the formation of acid mine drainage. Alkaline amino acids were used as electrolytes to explore the electrochemical oxidation mechanism of pyrite. Through electrochemical methods such as OCP, CV, Tafel polarization curve, LSV, and EIS, the electrochemical behavior of pyrite surfaces was measured, confirming the feasibility of pyrite oxidation in an alkaline amino acid system. The oxidation mechanisms of pyrite were consistent across the 3 alkaline amino acids, with the oxidation rate of pyrite following the order: lysine>arginine>histidine. [ABSTRACT FROM AUTHOR]

The flotation characteristics of chalcopyrite, galena and sphalerite in the system with dextrin, sodium humate (HA-Na), cationic guar gum (CGG) and DP115 (modified polyacrylamide) as inhibitors and Z-200 as collector were investigated. The results showed that compared with the traditional system of adding macromolecular organic inhibitor first and then adding Z-200 collector, the three sulfide minerals showed different flotation behaviors in the system of adding Z-200 first and then adding macromolecular organic inhibitor. Chalcopyrite was basically not affected by dextrin, while dextrin more strongly inhibits galena, sphalerite was slightly activated by lower dosage of dextrin and was equivalent to that of adding dextrin first and then adding Z-200, and higher dosage of dextrin slightly enhanced the inhibition of sphalerite. HA-Na weakened the inhibition of three sulfide minerals. The inhibition of CGG on sphalerite, especially chalcopyrite, was enhanced, while the inhibition of galena was basically equivalent to that of CGG when added first. Chalcopyrite was basically not affected by DP115, and the lower amount of DP115 more strongly inhibited galena and sphalerite, while the inhibition of higher amount of DP115 on galena and sphalerite was basically the same as that of adding DP115 first and then Z-200. The research results can provide reference for the selection of organic macromolecular inhibitors and the improvement of flotation separation efficiency when Z-200 was used as collector in the flotation separation of copper-lead-zinc sulfide ore. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION A colorimetric method for the quantification of hydrogen sulfide (H₂S) produced in microbial fermentations was developed using lead gelled alginate microparticles packed in glass columns. The formation of a lead sulfide complex, between H₂S and lead ion (Pb2+) immobilized on the microparticles, allowed simple and accurate quantification by colorimetry.The microparticle‐loaded columns were calibrated and showed significant analytical sensitivity. The calibration curve of the system showed a correlation coefficient (r2) of 0.995 and a detection limit of 1.29 ± 0.02 μg L−1. The application of the columns in laboratory wine fermentations was able to detect variations in H2S production from 10.6 to 23.5 μg L−1 by increasing the sugar content in the medium, and from 10.6 to 3.2 μg L−1 with decreasing nitrogen content in the medium.Validation of the proposed method was carried out by determining H₂S in a vinic fermentation model, the results of which were compared with those obtained using a reference chemical method. The data obtained showed no statistically significant differences between the two methods, confirming the reliability and accuracy of the developed system. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study employs microwave roasting to decompose smithsonite mineral (zinc carbonate) into zinc oxide, which then reacts with pyrite to sulfurize its surface, forming zinc sulfide. This process is beneficial for the flotation recovery of zinc oxide minerals. The surface sulfidation behavior of smithsonite under low-temperature microwave roasting conditions is examined through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermodynamic calculations. XRD and thermodynamic analysis indicate that smithsonite completely decomposes into zinc oxide at 400 °C. Introducing a small amount of pyrite as a sulfidizing reagent leads to the formation of sulfides on the surface of decomposed smithsonite. XPS analysis confirms that the sulfide formed on the surface is zinc sulfide. SEM analysis reveals that sulfides are distributed on the surface of smithsonite, and the average sulfur concentration increases with the pyrite dosage. Microwave-assisted sulfurization of smithsonite (ZnCO3) was found to significantly enhance its floatability compared to conventional sulfurization methods. The optimal mass ratio of ZnCO3 to FeS2 is approximately 1:1.5, with the best temperature being 400 °C. These findings provide a technical solution for the application of microwave roasting in the efficient recovery of smithsonite through flotation. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the mineralogical and chemical composition of zinc and lead metallurgical slags. These slags contain numerous elements, including toxic metals, which form conglomerates or multiphase intergrowths. The phase composition of slags is one of the main factors that determine their behaviour in weathering environments, that is, their ability to release metals when exposed to atmospheric factors. In this paper, the release of elements from slags and their mobility in a hypergenic environment is determined based on the results of leachability tests and on geochemical modelling, thus assessing the environmental impact of landfilled slags. The elements released from slags in the largest quantities are zinc and lead. Zn is leached out over a long period of time. It was found that after 12 years, the concentration of Zn in the eluate exceeds by 40 times the permissible value of 200 mg/kg for hazardous waste. The degree of leaching of lead from slags as a function of time (after 12 years), despite its significant solubility in water, is much lower than the degree of leaching of zinc. The most mobile phase components of slags in the studied hypergenic environment are the lead phases (anglesite and galena) and, to a lesser extent, the zinc phases (sphalerite and willemite). Anglesite and galena in almost the entire Eh-pH range, along with admixtures of elements, decompose into ionic forms: PbCl42−, Pb2+, and PbOH+. Sphalerite in the soil and water environment (oxidizing and acidic conditions) will decompose into the mobile ionic form Zn2+. Willemite, which is resistant to weathering, will undergo similar decomposition. It can therefore be assumed that the carriers of toxic metals are primarily lead sulphides and sulphates, zinc sulphides, and, less frequently, zinc, lead, and iron oxides. [ABSTRACT FROM AUTHOR]

Quantitative fluorescence quenching is a common analytical approach to studying the mechanism of chemical reactions. The Stern–Volmer (S–V) equation is the most common expression used to analyze the quenching behavior and can be used to extract kinetics in complex environments. However, the approximations underlying the S–V equation are incompatible with Förster Resonance Energy Transfer (FRET) acting as the primary quenching mechanism. The nonlinear distance dependence of FRET leads to significant departures from "standard" S–V quenching curves, both by modulating the interaction range of donor species and by increasing the effect of component diffusion. We demonstrate this inadequacy by probing the fluorescence quenching of long-lifetime lead sulfide quantum dots mixed with plasmonic covellite copper sulfide nanodisks (NDs), which serve as perfect fluorescent quenchers. By applying kinetic Monte Carlo methods, which consider particle distributions and diffusion, we are able to quantitatively reproduce experimental data, which show significant quenching at very small concentrations of NDs. The distribution of interparticle distances and diffusion are concluded to play important roles in fluorescence quenching, particularly in the shortwave infrared, where photoluminescent lifetimes are often long relative to diffusion time scales. [ABSTRACT FROM AUTHOR]

Colloidal quantum dot (CQD) based infrared (IR) photodetectors offer facile wavelength tunability in the IR and low‐cost fabrication. However, owing to their large surface areas, CQDs intrinsically have significant surface traps critically affecting the speed of CQD photodetectors, typically mediated through tedious surface passivation efforts. In this report, an alternative strategy involving coupling of near‐IR photoactive lead sulfide CQDs with a thermally evaporated amorphous selenium (a‐Se) hole transport layer is proposed. By separating the detector into a photon absorbing CQD region and a charge transport a‐Se region, the study takes advantage of the extremely low noise, predominantly hole‐only transport process in a‐Se. A high 3 dB bandwidth of 2.5 MHz and a competitive specific detectivity of 2.5 × 1011 Jones at room temperature are demonstrated at 980 nm. This report serves as a first demonstration of strong coupling between an IR active CQD absorber and a‐Se, which paves the path to obtain fast and highly photoresponsive IR photodetection in the future. [ABSTRACT FROM AUTHOR]

In this study, on the fabrication of a flexible wavelength sensor is reported, which is achieved by growing a layer of lead sulfide (PbS) nanofilm on both sides of a polyethylene terephthalate substrate using the chemical bath deposition method, followed by the deposition of two parallel Au interdigital electrodes. Experimental result shows that the photocurrent ratio of the two photodetectors monotonically decreases with increasing wavelength in the range from 265 nm (UV) to 2000 nm (NIR), indicating that the incident light wavelength can be distinguished by the photocurrent ratio. Notably, the as‐constructed wavelength sensor exhibits superior performance compared to most previously reported filter‐less designs, achieving an average absolute error of 11.5 nm and an average relative error of 1.1%. It is also found that the sensor exhibits excellent mechanical flexibility and environmental stability. Furthermore, by introducing the back‐end circuit, real‐time detection of the wavelength of monochromatic light and the peak wavelength of LED light are achieved, with detection errors not exceeding 2.8% and 2.6%, respectively. It is believed that the flexible PbS nanofilm wavelength sensor prepared in this study has potential application in future portable and flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]

Cerussite is an essential lead oxide mineral with increasing economic importance as lead sulfide resources deplete. This study utilizes density functional theory (DFT) to investigate the structural and electronic properties of the sulfurized cerussite (110) surface. The results show that when the cerussite crystal cleaves along the (110) plane, only the surface layer atoms undergo relaxation to reconstruct the surface, while the atoms located deeper have almost no impact on the reconstructed surface structure. The Pb atoms on the cerussite (110) surface react with the sulfurizing agent to form a PbS deposition layer with a structure similar to galena. This PbS deposition layer is tightly adsorbed onto the lead oxide layer through Pb-S bonds formed by S and subsurface lead oxide structure Pb atoms. The chemical reactivity of Pb atoms in the PbS layer on the sulfurized cerussite (110) surface is more potent than that of Pb atoms on the galena surface; additionally, the Pb atoms closer to the lead oxide layer exhibit slightly higher chemical reactivity than those farther away. This study provides insight into sulfurized cerussite surfaces' structure and properties at an atomic level and assists in explaining the floating behavior of cerussite. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots (CQDs)-based near and shortwave infrared (SWIR) light emitting diodes (LEDs) have significantly advanced in recent years. Despite the improvement, the performance is still inferior to that of their counterparts in the visible range. Developing a device simulation methodology is vital to studying the loss mechanism and reducing the losses to achieve high-performance SWIR LEDs. Here, we report a novel technique to simulate lead sulfide (PbS) CQD-based SWIR LED performance using 1-dimensional Solar Cell Capacitance Simulation (SCAPS-1D) software. The platform solves the basic semiconductor equations to estimate the radiative and non-radiative recombination in the active layer. The role of various material parameters like emitter bandgap, trap density, recombination coefficients, and band offset for charge injection on device performance was investigated. The simulation shows that the most dominating loss factor for PbS LEDs in higher injection domains is the Auger recombination, whereas, in lower voltage regimes, trap-assisted non-radiative recombination pathways are prominent. The simulation validates the experimentally reported device performances and guides the roadmap for achieving external quantum efficiency above 20% in these devices. [ABSTRACT FROM AUTHOR]

During the production process of sulfide lead-zinc ore using the flotation method, a large amount of beneficiation wastewater is generated. The pH value, suspended solids, chemical oxygen demand, heavy metal ions, etc. in the beneficiation wastewater often exceed the water quality standard limits. Direct discharge of mineral processing wastewater will disturb the water environment in the mining and surrounding areas. Direct reuse will cause fluctuations and deterioration of mineral processing production indicators. Therefore, lead-zinc mining production enterprises must treat mineral processing wastewater and discharge it in compliance with standards or recycle it back to the mineral processing plant for production use. Taking Dongtangzi Lead Zinc Mine in Feng County, Shaanxi Province as an example, this paper elaborates on the method of fully recycling mineral processing wastewater and the achieved results. In order to reduce the impact of mineral processing wastewater on production and mineral processing indicators, the circulation volume and water quality of mineral processing wastewater were analyzed and monitored, and the reasons affecting mineral processing production were identified. Through research and investigation, a wastewater treatment process suitable for the company was designed. By continuously adjusting and optimizing the mineral processing agent system (including changing the lime dosing point and reducing the lime dosage, using Z-1 flotation agent, MB collector, and BK204 frother reducing, the dosage of copper sulfate and ethyl sulfide nitrogen, and discontinuing the use of Na2SO3 K2Cr2O6, Na2CO3, ZnSO4, xanthate, terpineol oil and other reagents, the total amount of mineral processing reagents hasbeen reduced from 13 295 g/t to 6 500 g/t, with a reduction by 6 795 g/t and a decrease of 51%. At the same time, the flocculation effect of lime and Z-1 flotation agent, as well as the inhibitory effect of Z-1 flotation agent on heavy metals and carbon-containing substances, purify the flotation operation environment, enabling wastewater treatment and mineral processing operations to be carried out simultaneously in the production process, eliminating the impact of fully recycled mineral processing wastewater on production. Mineral processing wastewater only needs to be naturally settled in the tailings pond and can be fully recycled for mineral processing production without the specific wastewater treatment, achieving full recycling of mineral processing wastewater. The dosage and cost of reagents are significantly reduced, and the mineral processing indicators are significantly improved. The results can provide a reference for the recycling of similar lead-zinc ore beneficiation wastewater. [ABSTRACT FROM AUTHOR]

Colloidal semiconductor nanoparticles (NPs) represent an emergent state of matter with unique properties, bridging bulk materials and molecular structures. Their distinct physical attributes, such as bandgap and photoluminescence, are intricately tied to their size and morphology. Ligand passivation plays a crucial role in shaping NPs and determining their physical properties. Ligand exchange (LE) offers a versatile approach to tailoring NP properties, often guided by Pearson's Hard–Soft Acid–Base theory. Lead sulfide (PbS), a semiconductor of considerable interest, exhibits size-dependent tunable bandgaps from the infrared to the visible range. Here, we present two methods for synthesizing water-soluble, polyvinylpyrrolidone (PVP)-coated PbS NPs. The first involves direct synthesis in an aqueous solution while utilizing PVP as the surfactant for the formation of nano-cubes with a crystal coherence length of ~30 nm, while the second involves LE from octadecylamine-coated PbS truncated nano-cubes to PVP-coated PbS NPs with a crystal coherence length of ~15 nm. Multiple characterization techniques, including X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and thermal gravimetric analysis, confirmed the results of the synthesis and allowed us to monitor the ligand exchange process. Our findings demonstrate efficient and environmentally friendly approaches for synthesizing PVP-coated PbS NPs. [ABSTRACT FROM AUTHOR]

This study presents a versatile and efficient method to synthesize large‐size lead sulfide (PbS) quantum dots (QDs) that display emission in the short‐wave infrared (SWIR) region, using accessible and stable diethylammonium diethyldithiocarbamate (C2)2DTCA and octylammonium octyldithiocarbamate (C8DTCA) as sulfur sources. As these sulfur sources enable the formation of well‐dispersed, large‐size PbS QDs in a very convenient way, this method can further be taken up for scale‐up studies. Importantly, this approach allows precise control over QD sizes, thereby enhancing their SWIR optical properties. By adjusting the hot injection temperatures and sulfur source concentrations, different synthesis routes are explored, providing flexibility for the desired QD characteristics. The results presented here offer a promising opportunity to leverage the synthesized PbS QDs in applications such as optoelectronics, sensors, and imaging technology. [ABSTRACT FROM AUTHOR]

In this study, we investigated the influence of Cu doping and gamma irradiation on the photocatalytic activity of lead sulfide (PbS) nanoparticles for methylene blue (MB) degradation under solar light. The optical bandgap of the γ-irradiated Pb (1-x) Cu x S (where x = 0 to 0.02) was calculated between 2.29 eV - 2.72 eV, facilitating the modulation of optical bandgaps in PbS. Additional analyses incorporating photoluminescence and the Brunauer (Emmett) Teller method were used to determine optical properties, surface area, and pore distribution. The photocatalytic degradation of MB under sunlight irradiation was investigated. The photocatalytic activity was enhanced with the increasing rate of MB degradation. Notably, gamma-irradiated Pb 0.99 Cu 0.01 S exhibited a remarkable MB degradation efficiency of 73.64 %, demonstrating its stability over three consecutive cycles. This underscores its inherent stability and potential for repeated use. Overall, these findings highlight the significant potential of gamma-irradiated Cu-doped PbS nanoparticles as durable, renewable photocatalysts for efficient degradation in an aqueous media, thereby offering a promising approach for environmental remediation. [ABSTRACT FROM AUTHOR]

Ultrathin cells are gaining popularity due to their lower weight, reduced cost, and enhanced flexibility. However, compared to bulk cells, light absorption in ultrathin cells is generally much lower. This study presents a numerical simulation of a metamaterial light management structure made of ultrathin lead sulfide colloidal quantum dots (PbS CQDs) sandwiched between a top ITO grating and a tungsten backing to develop an efficient hybrid solar/thermophotovoltaic cell (HSTPVC). The optical properties were computed using both the finite integration technique (FIT) and the finite element method (FEM). The absorptance enhancement was attributed to the excitations of magnetic polaritons (MP), surface plasmon polaritons (SPP), and lossy mode resonance (LMR). The HSTPVC with the metamaterial optical light management structure was assessed for short-circuit current density, open-circuit voltage, and conversion efficiency. The results show a conversion efficiency of 18.02% under AM 1.5 solar illumination and a maximum thermophotovoltaic conversion efficiency of 12.96% at TB = 1600 K. The HSTPVC can operate in a hybrid solar/thermal conversion state when the ITO grating is included by combining the advantages of QDs and metamaterials. This work highlights the potential for developing a new generation of hybrid STPV cells through theoretical modeling and numerical simulations. [ABSTRACT FROM AUTHOR]

Lead sulfide colloid quantum dots (PbS QDs) offer great opportunities to revolutionize large‐area short‐wave infrared (SWIR) detection technologies due to high absorption coefficients and spectral selectivity. However, a critical issue for QDs‐based SWIR detectors is high dark current noise due to thermal carriers and the large amounts of surface defect states induced by the ligand exchange process, which hinders the improvement of the room temperature detectivity and linear dynamic range. Herein, it is demonstrated that these dilemmas can be overcome by adopting a novel hybrid‐layered phototransistor device architecture composed of a self‐assembly high‐mobility organic conduction channel and a bulk heterojunction infrared absorber containing PbS QDs as sensitizers. Strong photo absorption in the photoactive layer creates photogenerated charges that are transferred to the conduction channel, where they recirculate many times due to the long trapped‐electron lifetime in the photoactive layer and the high carrier mobility of the channel. Therefore, low dark current noise and high photoconductive gain are achieved by both electrical gating and photodoping for carrier‐density modulation of phototransistors. Finally, an optimized SWIR phototransistor device with a low room‐temperature dark current of 7 pA and a high detectivity of 8 × 1012 Jones under 1650 nm light illumination is demonstrated. [ABSTRACT FROM AUTHOR]

The ternary metal sulfide CoS2:Ni17S18:Al2S3 thin films were created in the presence of diethyldithiocarbamate as a sulfur source, pursued by physical vapour deposition. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-visible spectrophotometer, and Fourier transform infrared spectroscopy were used to identify and characterize the synthesised substances. The ternary metal sulfide had a mean crystallite size of 37.8 nm on the nanoscale. SEM revealed spherical particles with rounded edges particles. XPS presented Al 2p, Co 2p, Ni 2p and S 2p core level peaks of the elements. The ternary metal sulfide had a band gap energy of 3.49 eV. The phenomenal storage technology potential of the thin film was evaluated using cyclic voltammetry that revealed an astounding supercapacitance of 515 F g−1, demonstrating the material's effectiveness. Voltammetric findings show the cycling stability of the nanoparticle thin film. Moreover, the photocatalytic degradation of contaminants such as methylene blue dye, pesticide zoxamide, and phenol was probed, with such a spectacular degradation rate constant of 4.11 × 10−2 min−1 with 91.5% degradation achieved for pesticide. [ABSTRACT FROM AUTHOR]

In the present paper, we have conducted both theoretical and experimental investigations on thin films of lead sulfide (PbS). The structural and morphological properties of these films, which were prepared using the spray pyrolysis method, were analyzed utilizing X-ray diffraction (XRD) and scanning electron microscopy (SEM). Theoretical calculations were performed employing the first principles full potential linearized augmented plane wave (FP-LAPW) approach. The findings of this study reveal that the PbS film that was deposited is polycrystalline and possesses a rock-salt structure. The SEM image depicts a planar structure with dimensions ranging from 480 to 930 nm. The results obtained through energy dispersive spectroscopy (EDS) indicate high crystalline quality, and the film surface exhibits a rough texture and a dense morphology. In terms of its behavior, PbS acts as a semiconductor with a direct optical band gap situated at the L point of the Brillouin zone (BZ). The density of states on both sides of the band gap is primarily of s-p character. The ionic nature of PbS can be attributed to charge transfer. A substantial level of agreement has been observed between the experimental and theoretical results. Our ongoing research endeavors aim to explore biosensors and their various applications. The novelty of this work lies in the combined study of the structural and morphological properties of PbS films grown using the spray pyrolysis technique, employing both experimental and theoretical approaches. This paper describes a comprehensive approach to understanding bulk and thin-film PbS materials through theory and experimentation. [ABSTRACT FROM AUTHOR]

Silicon photonics faces a persistent challenge in extending photodetection capabilities beyond the 1.6 µm wavelength range, primarily due to the lack of appropriate epitaxial materials. Colloidal quantum dots present a promising solution here, offering distinct advantages, such as infrared wavelength tunability, cost-effectiveness, and facile deposition. Their unique properties position them as a potential candidate for enabling photodetection in silicon photonics beyond the conventional telecom wavelength, thereby expanding the potential applications and capabilities within this domain. In this study, we have successfully integrated lead sulfide (PbS) colloidal quantum dot photodiodes (QDPDs) onto silicon waveguides using standard process techniques. The integrated photodiodes exhibit a remarkable responsivity of 1.3 A/W (with an external quantum efficiency of 74.8%) at a wavelength of 2.1 µm, a low dark current of only 106 nA, and a bandwidth of 1.1 MHz under a −3 V bias. To demonstrate the scalability of our integration approach, we have developed a compact 8-channel spectrometer incorporating an array of QDPDs. This achievement marks a significant step toward realizing a cost-effective photodetector solution for silicon photonics, particularly tailored for a wide range of sensing applications around the 2 µm wavelength range. [ABSTRACT FROM AUTHOR]

The effect of adding orders of inorganic regulators such as zinc sulfate, copper sulfate, sodium sulfite and sodium sulfide on the flotation of chalcopyrite, galena, and sphalerite was studied under the Z-200 collector system. The results of microflotation tests showed that compared with adding inorganic regulator before the Z-200, when the inorganic regulator was added after the Z-200, there were differences in the effect on the flotation of the three kinds of sulfide minerals: the depressing effect of zinc sulfate on chalcopyrite, especially galena, was significantly weakened, and the depressing effect of zinc sulfate on sphalerite was weakened at lower dosage, but stronger at higher dosage. Copper sulfate slightly enhanced the depressing effect on chalcopyrite, had a strong activation effect on galena, especially at lower dosage, the activation effect of copper sulfate on sphalerite was significantly enhanced at lower dosage, and was weakened at higher dosage. Sodium sulfite weakened its depressing effect on chalcopyrite, especially galena, and enhanced the depressing effect on sphalerite. Sodium sulfide weakened its depressing effect on chalcopyrite, had a similar activation effect on galena at lower dosage, while its depressing effect was enhanced at higher dosage, and enhanced its depressing effect on sphalerite at low dosage. The research results can provide reference for the selection and the adding sequence of inorganic regulators in the flotation separation of sulfide ores under the Z-200 collector system. [ABSTRACT FROM AUTHOR]

[Display omitted] Organic solar cells have been fabricated using various concentrations of lead sulfide quantum dots. Data from Mott–Schottky analysis revealed intriguing changes in the bulk heterojunction layer of the solar cells that were directly related to the addition of the quantum dots. Notably, the highest power conversion efficiency of 5.15% was achieved with the addition of 0.4 wt% lead sulfide quantum dots. [ABSTRACT FROM AUTHOR]

Lead sulfide (PbS) colloidal quantum dots (CQDs) is emerging as a promising material for infrared photodetectors because of its strong absorbance in the near infrared region, the tunable energy gap, facile fabrication, and excellent electrical properties. This Tutorial gives a comprehensive introduction of materials and devices of PbS CQD based infrared photodetectors. First, we introduce the concept of CQDs and the typical characters of CQDs. The synthesis of PbS CQDs and a solid film fabrication method are then summarized. Subsequently, the study for defect passivation and carrier transport in a PbS CQD thin film is presented. In the end, the device structure, the electrical diagram, and strategies for enhancing device performance of three kinds of infrared photodetector are concluded. [ABSTRACT FROM AUTHOR]

The integration between infrared detection and modern microelectronics offers unique opportunities for compact and high-resolution infrared imaging. However, silicon, the cornerstone of modern microelectronics, can only detect light within a limited wavelength range (< 1100 nm) due to its bandgap of 1.12 eV, which restricts its utility in the infrared detection realm. Herein, a photo-driven fin field-effect transistor is presented, which breaks the spectral response constraint of conventional silicon detectors while achieving sensitive infrared detection. This device comprises a fin-shaped silicon channel for charge transport and a lead sulfide film for infrared light harvesting. The lead sulfide film wraps the silicon channel to form a “three-dimensional” infrared-sensitive gate, enabling the photovoltage generated at the lead sulfide-silicon junction to effectively modulate the channel conductance. At room temperature, this device realizes a broadband photodetection from visible (635 nm) to short-wave infrared regions (2700 nm), surpassing the working range of the regular indium gallium arsenide and germanium detectors. Furthermore, it exhibits low equivalent noise powers of 3.2×10−12 W·Hz−1/2 and 2.3×10−11 W·Hz−1/2 under 1550 nm and 2700 nm illumination, respectively. These results highlight the significant potential of photo-driven fin field-effect transistors in advancing uncooled silicon-based infrared detection.

In this study, lead(II) sulphide (PbS) nanoparticles of varying particle sizes were synthesized using the hot injection method, employing 1-octadecene (ODE) as a coordinating ligand in conjunction with oleylamine (OAm). This synthesis approach was compared with the preparation of hexagonal-shaped nanoparticles through the ligand of 1-Dodecanethiol (DT), resulting in DT-capped PbS nanoparticles. The prepared nanoparticles were characterized using multiple techniques including photoluminescence (PL), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The condensation reaction of DT ligands led to various nanoparticles within the range of 34.87 nm to 35.87 nm across different synthesis temperatures (120 °C, 150 °C, 180 °C, 210 °C, and 240 °C). The PbS with DT ligands exhibited a highly crystalline and superhydrophilic structure. Interestingly, near-infrared (NIR)-PL analysis revealed peaks at 1100 nm, representing the lowest-energy excitonic absorption peak of PbS nanoparticles for both ligands. This suggests their potential utility in various applications, including IR photoreactors, as well as in the development of non-toxic nanoparticles for potential applications in in vivo bioimaging. [ABSTRACT FROM AUTHOR]

The n‐type quantum dot (QD) active layer is the core component of lead sulfide QD solar cells (PbS QDSCs). In the state‐of‐the‐art PbS QDSCs, the active layer is commonly obtained through liquid‐phase ligand exchange (LPLE). Due to the intricate chemical state of the ligand exchange solution providing halide ligand, therefore, the PbS‐OAQD solutions is used at concentrations of 20, 30, and 40 mg mL−1 for LPLE, aiming to investigate the reasons for different surface states post‐exchange and their impact on device performance. The results indicate that when the concentration of the PbS‐OA QD solution is 30 mg mL−1, the exchanged QDs exhibit complete removal of surface OA, a higher content of short‐chain ligand PbX2 (X = I, Br), Consequently, devices fabricated using PbS‐PbX2 QD obtained through the exchange of 30 mg mL−1 PbS‐OA QD solution achieve a higher power conversion efficiency (PCE) of 12.53%. This study presents a simple and effective strategy to enhance the performance of PbS QDSCs. [ABSTRACT FROM AUTHOR]

Designing effective strategies for mitigating energy crisis highlights a research gap in current solar cell technologies. This study explores the inherent physicochemical properties of thin films composed of copper gallium sulfide telluride (CuGa1−xCrx(S,Te)2) with chromium substitution, prepared through the chemical spray pyrolysis technique. The investigation showcases how the concept of intermediate band structuring contributes to enhancing solar cell efficiency. This enhancement can be attributed to the remarkable mobility (from 1.80 to 5.48 cm2 V−1 s−1) and conductivity (from 1.00 to 6.06 S cm−1) exhibited by pure and 0.1 chromium thin films, respectively. Notably, the Cr‐0.1‐substituted CGST film displays maximum photoresponsivity of 0.624 AW−1, an external quantum efficiency of 145%, and a detectivity of 2.37E10. The fabricated solar cell is subjected to theoretical simulation using solar cell capacitance simulator‐1D software, revealing an upward trend in efficiency from 7.13% to 11.23% with increasing Cr substitution from 0.025 to 0.1. This efficiency improvement can be ascribed to the reduction in bandgap (from 2.40 to 1.72 eV) and the creation of a sub‐band in CGST due to Cr incorporation, as substantiated by UV–vis and NIR spectroscopy. These outcomes suggest that Cr‐0.1‐substituted CGST holds promise as a potential thin film absorber material in solar photovoltaics. [ABSTRACT FROM AUTHOR]

Strong emission over a wide near-infrared (NIR) region makes lead sulfide quantum dots (QDs) a preferred material in building NIR light-emitting diodes (NIR-LEDs) for numerous applications. Narrow-bandgap emitter QDs blended in the matrix of high-band gap QDs offer a simple yet powerful architectural platform for building high-performance NIR-LEDs. So far, the all-QD-based blend architecture has been realized using a poorly controlled solid-state ligand exchange approach. Advanced solution-phase ligand exchange, which offers greater control over surface passivation, is yet to be realized in all-QD LED device construction. We observe that the solution-phase ligand exchange from the optimized lead halide and thiol ligand combination, used in high-performing QD solar cell construction, is inefficient in realizing efficient all-QD LEDs, which could have restricted the adoption of the solution-phase ligand exchange thus far. Here, we introduce an innovative dual-ligand strategy to build all-QD-based NIR-LEDs using an advanced solution-phase ligand exchange approach. Through ligand engineering of matrix QDs, we managed to improve photoluminescence quantum yield (40%), reduce trap density (1014 cm–3), and prolong carrier lifetime (832 ns). The LED devices benefit from improved electronic properties and balanced carrier injection to yield 6% EQE and 7.7% PCE, which are six times higher than those of state-of-the-art ligands. [ABSTRACT FROM AUTHOR]

Since their discovery in 1981, quantum dots (QDs) have been the center of attention in optoelectronic fields owing to their excellent properties such as clearly discrete band structure, high luminous efficiency, and tunable energy bandgap via dot size control. Among them, the bandgap increase characteristic based on the quantum confinement effect opens a new horizon in the field of deep ultraviolet photodetectors (DUV PDs). Emerging applications such as risk monitoring, wireless optical communication, and chemical sensing with extremely low environmental interference raise the significance of DUV PDs. Nonetheless, the limited material selection for DUV absorption has been the main obstacle for further applications. Along this line, this review systematically revisits the recent advances in QD‐based DUV PDs, using bandgap‐widened QDs, with a focus on the synthetic method, device architecture, and interactions among constituent components. Various QDs categorized into carbon, oxide, sulfide, and nitride are reviewed with the specific characteristics of each substance. The future prospects of QD‐based DUV PDs in terms of practical applications and the current challenges are discussed. [ABSTRACT FROM AUTHOR]

Recently protein binders have emerged as a promising substitute for antibodies due to their high specificity and low cost. Herein, we demonstrate an electrochemical biosensor chip through the electronic labelling strategy using lead sulfide (PbS) colloidal quantum dots (CQDs) and the unnatural SARS-CoV-2 spike miniprotein receptor LCB. The unnatural receptor can be utilized as a molecular probe for the construction of CQD-based electrochemical biosensor chips, through which the specific binding of LCB and the spike protein is transduced to sensor electrical signals. The biosensor exhibits a good linear response in the concentration range of 10 pg mL−1 to 1 μg mL−1 (13.94 fM to 1.394 nM) with the limit of detection (LOD) being 3.31 pg mL−1 (4.607 fM for the three-electrode system) and 9.58 fg mL−1 (0.013 fM for the HEMT device). Due to the high sensitivity of the electrochemical biosensor, it was also used to study the binding kinetics between the unnatural receptor LCB and spike protein, which has achieved comparable results as those obtained with commercial equipment. To the best of our knowledge, this is the first example of using a computationally designed miniprotein receptor based on electrochemical methods, and it is the first kinetic assay performed with an electrochemical assay alone. The miniprotein receptor electrochemical biosensor based on QDs is desirable for fabricating high-throughput, large-area, wafer-scale biochips. [ABSTRACT FROM AUTHOR]

In this study, we synthesised and characterised a new zinc(II) triazenide for potential use in vapour deposition of zinc sulphide thin films. The compound is volatile and quantitatively sublimes at 80 °C under vacuum (0.5 mbar). Thermogravimetric analysis showed a one-step volatilisation with an onset temperature at ∼125 °C and 5% residual mass. The compound also reacted with 2 or 4 molar equivalents of triphenylsilanethiol to give dimeric and monomeric zinc thiolates, respectively. The high volatility, thermal stability, and reactivity with sterically hindered thiols makes this compound a potential candidate for use in vapour deposition of zinc containing thin films. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of vanadium sulfide (VxSy) by atomic layer deposition (ALD) based on the use of tetrakis(dimethylamino) vanadium (IV) and hydrogen sulfide is presented for the first time. The (ultra)thin films VxSy are synthesized in a wide range of temperatures (100–225 °C) and extensively characterized by different methods. The chemical composition of the VxSy (ultra)thin films reveals different vanadium oxidation states and sulfur‐based species. Extensive X‐ray photoelectron spectroscopy analysis studies the effect of different ALD parameters on the VxSy chemical composition. Encouraged by the rich chemistry properties of vanadium‐based compounds and based on the variable valences of vanadium, the electrochemical properties of ALD VxSy (ultra)thin films as electrode material for supercapacitors are further explored. Thereby, nanotubular composites are fabricated by coating TiO2 nanotube layers (TNTs) with different numbers of VxSy ALD cycles at low temperature (100 °C). Long‐term cycling tests reveal a gradual decline of electrochemical performance due to the progressive VxSy thin films dissolution under the experimental conditions. Nevertheless, VxSy‐coated TNTs exhibit significantly superior capacitance properties as compared to the blank counterparts. The enhanced capacitance properties exhibited are derived from the presence of chemically stable and electrochemically active S‐based species on the TNTs surface. [ABSTRACT FROM AUTHOR]

The present work is devoted to studying the effect of temperature on the formation of a submicron-sized particles of lead sulfide (PbS). Lead sulfide samples were obtained by chemical bath deposition method. 25 ml of an aqueous solution of lead nitrate Pb(NO3)2, 75 ml of sodium hydroxide NaOH and 50 ml of thiourea CH4N2S with molar concentrations of 0.18 M (1.52 g), 0.38 M (1.151 g) and 0.11 M (0.397 g), respectively, were used as reagents. In the process of obtaining samples, solutions of lead nitrate and sodium hydroxide were initially mixed at temperatures of 70℃ and 100℃, then a thiourea solution was added to this mixture. It was found that temperature has an effect on the formation of PbS structures. It is shown that at a temperature of 100℃ isolated particles are formed, whereas at a temperature of 70℃ a film is formed. The morphology and elemental composition of the obtained lead sulfide (PbS) samples were studied by scanning electron microscopy (SEM) and the surface structure was studied using an atomic force microscope (AFM). As a result of the study of the morphology and texture of the surface of lead sulfide samples, the average size of isolated particles was determined, which is ~144 nm, and these particles also had a cubic shape with a smooth surface. [ABSTRACT FROM AUTHOR]

Undoped and Chromium (Cr) doped (2, 4%) copper sulfide (Cu2S) nanostructured thin films were created by spray pyrolysis. The films were polycrystalline and combined cubic and monoclinic structures, according to the results of the XRD investigation. Surface roughness values for the doped and undoped thin films are 8.71, 7.79, and 3.24 nm, respectively. SEM images display Cu2S nanostructures with fine crystallites and traces of nanorod. Chromium doping increases particle size and induces nanorod growth, enhancing surface porosity. The optical examination shows that Cr-doped Cu2S thin films exhibit effective absorption (> 104 orders) in the visible range. From the change in absorption coefficient, it can be observed that there is a valley around 2.6 eV. By doping Cr (up to 2%) in Cu2S films, it is possible to control the band gap between 2.62 eV and 2.73 eV. The refractive index of undoped Cu2S films decreases with increasing Cr-doping concentration. Gas sensing of Chromium-doped and undoped Cu2S nanostructures involves dynamic resistance change at 100°C. Undoped Cu2S displays low resistance, exhibiting p-type semiconductor behavior. Notably, 4% Cr-doped Cu2S shows high resistance, and the introduction of NO2 decreases resistance. Decreased sensitivity with rising Cr doping in Cu2S: 2% Cr and Cu2S: 4% Cr. Responsiveness declined across different NO2 concentrations (200 ppm, 300 ppm, and 400 ppm). [ABSTRACT FROM AUTHOR]

This article deals with the optimization by simulation of a graded bandgap thin film solar cell based on antimony selenosulfide Sb2(Se1-ySy)3 having the following structure: Front contact/n-ZnO/i-ZnO/p-SbSSe/n-CdS/Back contact. The simulation is performed using SCAPS-1D software. The optimization process includes optimizing the bulk defect density, bandgap profile, material composition, thickness, and doping density of the absorber layer of thin film solar cell based on antimony selenosulfide Sb2(Se1-ySy)3. We found that for a bulk defect density below 1013 cm-3, using an absorber material with a graded bandgap profile leads to an efficiency of 25.33 % (For a bulk defect density of 1010 cm-3) higher than that with a uniform bandgap profile. However, for a bulk defect density of 1013 cm-3, both profiles provide almost the same maximum solar cell conversion efficiencies of about 13.6 %. Ultimately, for a bulk defect density above 1013 cm-3, the graded bandgap profile is not useful, and a maximum solar cell conversion efficiency of 10.5 % (For a bulk defect density of 1014 cm-3) is achieved with a uniform bandgap profile. These optimization results help to improve the efficiency of low-cost fabricated thin-film solar cells. [ABSTRACT FROM AUTHOR]

The ultrapure and stoichiometric semiconductor PbS-st thin film is manufactured for the first time by hydrochemical method. The width of the band gap Eg (295 K) = 0.39 eV is in a 0.3–0.7μm thick PbS-st film. The drift mobility of carriers of 320–480 cm2/(V s) and the carrier lifetime of 7–20 µs correspond to the best natural single crystals of PbS. When cooled to 140 K, the conductivity of PbS-st films decreases 10,000 times. This is already a dielectric. From the conductivity graph in the range of 140–295 K, the Hall band gap of Eg (4 K) = 0.34 eV is determined, which sharply differs from the known Eg (4 K) = 0.286 eV. The temperature coefficient of change is in the width of the optical zone dE/dT (140–323 K) = + 1.6 × 10–4 eV/K, which is 2.5 times less than the known one. Ultra-fast photodetectors with a time constant of τ = 8 µs and a detection ability of D*(2.4, 1000, 1) = 1.7 × 1010 cm Hz1/2/W were made. As well as photodetectors are similar to vacuum ones with τ = 40–70 µs and D*(2.4, 1000, 1,) = (4–6) × 1010 cm Hz1/2/W with a dark resistance of 40–120 kOhm/square. Oxygen-free photodetectors PbS have no analogues. [ABSTRACT FROM AUTHOR]

Galena is a natural mineral enriched with lead sulfide (PbS). It typically forms in hydrothermal veins associated with igneous rocks and can also occur as a gangue mineral in other ore deposits. PbS is of special importance for scientific research applications due to the possibility of tuning its semiconductor energy gap using nanotechnology in conjunction with powder metallurgy as an easy, controllable production route. In this paper, almost pure PbS was successfully produced starting from a high ratio of PbS phase galena ore. As-received galena lumps were roughly pulverized and milled to produce four particle size ranges of 38, 63, 125, and 250 µm prior to compaction and sintering in a vacuum (pre-flushed with argon gas). SEM coupled with the EDAX analysis unit was employed to investigate the microstructure and chemical composition of the as-received galena and the subsequent products after sintering. The chemical analysis confirmed the high ratio of PbS compound in the as-received galena and sintered products with approximately 85% Pb and 13% S mass ratio. The sintering process of the galena powder was carried out at different values of temperature, time, and compaction pressure. Additionally, the effect of length to diameter ratio of compacted and sintered samples was investigated. XRD analysis confirmed the existence of the PbS phase in the as-received and sintered samples at 700 °C with approximately 98 wt.%, as well as a new phase that is formed at 800 °C with a lower percentage. The micro-hardness of the as-received and sintered samples was measured and compared with the as-received galena ore. The results showed a significant reduction in the hardness of sintered galena powder compared with the bulk as-received galena by 52%. Furthermore, a relative sintered density of 99.3% for the as-received galena density signifies a novel result using powder metallurgy techniques. [ABSTRACT FROM AUTHOR]

Disclosing the full potential of functional nanomaterials requires the optimization of synthetic protocols and an effective size screening tool, aiming at triggering their size-dependent properties. Here we demonstrate the successful combination of a wide-angle X-ray total scattering approach with a deep learning classifier for quantum dots sizing in both colloidal and dry states. This work offers a compelling alternative to the lengthy process of deriving sizing curves from transmission electron microscopy coupled with spectroscopic measurements, especially in the ultra-small size regime, where empirical functions exhibit larger discrepancies. The core of our algorithm is an all-convolutional neural network trained on Debye scattering equation simulations, incorporating atomistic models to capture structural and morphological features, and augmented with physics-informed perturbations to account for different predictable experimental conditions. The model performances are evaluated using both wide-angle X-ray total scattering simulations and experimental datasets collected on lead sulfide quantum dots, resulting in size classification accuracies surpassing 97%. With the developed deep learning size classifier, we overcome the need for calibration curves for quantum dots sizing and thanks to the unified modeling approach at the basis of the total scattering method implemented, we include simultaneously structural and microstructural aspects in the classification process. This algorithm can be complemented by incorporating input information from other experimental observations (e.g., small angle X-ray scattering data) and, after proper training with the pertinent simulations, can be extended to other classes of quantum dots, providing the nanoscience community with a powerful and broad tool to accelerate the development of functional (nano)materials. [ABSTRACT FROM AUTHOR]

A Pb-free FASnI3 perovskite solar cell improved by using Cu2O/ZnO as two-dimensional-based hole/electron transport nanolayers has been proposed and studied by using a SCAPS-1D solar simulator. To calibrate our study, at first, an FTO/ZnO/MAPbI3/Cu2O/Au multilayer device was simulated, and the numerical results (including a conversion efficiency of 6.06%, an open circuit potential of 0.76 V, a fill factor parameter of 64.91%, and a short circuit electric current density of 12.26 mA/cm2) were compared with the experimental results in the literature. Then, the conversion efficiency of the proposed FASnI3-based solar cell was found to improve to 7.83%. The depth profile energy levels, charge carrier concentrations, recombination rate of electron/hole pair, and the FASnI3 thickness-dependent solar cell efficiency were studied and compared with the results obtained for the MAPbI3-containing device (as a benchmark). Interestingly, the FASnI3 material required to obtain an optimized solar cell is one-half of the material required for an optimized MAPbI3-based device, with a thickness of 200 nm. These results indicate that developing more environmentally friendly perovskite solar cells is possible if suitable electron/hole transport layers are selected along with the upcoming Pb-free perovskite absorber layers. [ABSTRACT FROM AUTHOR]

• Laser and photochemistry were first used in restoring and transformation of PbS on painted cultural relics. • Targeted fast realization of restoring and transformation of PbS, and without damage to the base color. • Laser catalysis restoration has wide applicability to papers, the silks and other organic materials. Lead white darkening is a common disease in all kinds of painted cultural relics. In this study, a combination of laser and photodynamic technology was used to achieve controlled restoration of lead sulfide at the lead darkening site on the painted layer of cultural relics by laser catalysis with porphyrin to produce singlet oxygen. The chromatic change, micromorphology and chemical composition were systematically studied for a simulated sample with the lead darkening part of the painted layer. The results show that laser catalytic treatment can repair the color darkening that occurs by the PbS formation, while no obvious changes to the pore and microparticle structure of the painted layer and the base. In this study, the pollutant of lead sulfide was proved to be converted into lead sulfate by oxidation, and then was converted to lead white by precipitation, which was the original composition of the pigment. It is also found that the laser catalytic treatment method can effectively avoid basic layer damages of cultural relics, especially for the papers, the silks and other organic materials. This technology not only provides a new approach for the restoration and transformation of PbS on painted cultural relics, but also makes available new applications for the laser and photodynamic technology in the field of cultural relics protection. [ABSTRACT FROM AUTHOR]

Lead Sulfide (PbS) nanoparticle-decorated silicon (Si) pyramids array on Si-based photocathodes are fabricated by using pure chemical methods. The PbS thin layers were synthesized by chemical solution deposition onto flat Silicon (Si) and pyramidal textured Silicon (SiPY) obtained from alkaline Si substrate etching. Scanning Electron Microscopy (SEM) was used to carry out the morphological characterization, while UV–Vis-NIR Spectroscopy was used to study the optical properties. The Linear sweep voltammetry (LSV) was conducted to study the catalytic activity in dark and under white light irradiation using a potentiostat station. Cyclic voltammetry in the presence of and without purging CO2 was also investigated. The LSV investigations showed the synergy effect between PbS thin films and Si for the rising and transport of the charge carriers. The results showed a higher photocatalytic towards CO2 reduction of PbS/SiPY compared to Silicon substrate without surface texturization and sensitization. The photoelectrode based on PbS/SiPY could efficiently be used as a photocathode for the photoelectrochemical (PEC) reduction of CO2 to Methanol. [ABSTRACT FROM AUTHOR]

The effect of lead sulfide (PbS) decoration on the photocatalytic properties of porous silicon (PS) was investigated. The PbS nanoparticles (PbS-NPs) are prepared by the successive ionic layer adsorption and reaction method (SILAR). The microstructure, surface morphology, phase composition, and optical properties of the prepared structure were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM and high-resolution mode HRTEM), and UV–Vis spectroscopy respectively. The PbS nanoparticle properties were altered by changing the SILAR cycles number (10 to 60 cycles) permitting a well-control of PbS-NP size and density. The synthesized nanohybrid system photocatalytic activity was investigated via the degradation of amido black dye (AB) as a pollutant model. The tested structures showed that the best enhancement of the photocatalytic removal of AB was reached with PbS-NPs deposited during 60 SILAR cycles with a reaction rate of 0.01096 min−1, exceeding that of pure PS layer. [ABSTRACT FROM AUTHOR]

In recent times, zero-dimensional materials have gained importance from a fundamental and technological perspective. Lead selenium sulphide (PbSeS) is a potential candidate for finding interest in its zero-dimensional form among many compound semiconductors. Hence, in this communication, we explored the impact of quantum confinement effects on the energy band gap and wavelength of PbSeS semiconductor nanocrystals (Quantum dots) using cohesive energy and hyperbolic band models (HBM). Experimental data, such as scanning electron microscopy, UV-Vis-NIR, and PL spectroscopies were used to determine the size of nanoparticles and wavelength. PbSeS nanocrystals were also prepared by one-pot synthesis. The experimental results showed that the prepared PbSeS nanostructures are formed with tiny nanometer size, which showed a redshift of about 0.79eV in energy bandgap. A theoretical study showed that the energy bandgap in quantum-sized PbSeS differs from that in its bulk crystal. [ABSTRACT FROM AUTHOR]

Lead Sulfide (PbS) nanoparticle-decorated silicon (Si) pyramids array on Si-based photocathodes are fabricated by using pure chemical methods. The PbS thin layers were synthesized by chemical solution deposition onto flat Silicon (Si) and pyramidal textured Silicon (SiPY) obtained from alkaline Si substrate etching. Scanning Electron Microscopy (SEM) was used to carry out the morphological characterization, while UV–Vis-NIR Spectroscopy was used to study the optical properties. The Linear sweep voltammetry (LSV) was conducted to study the catalytic activity in dark and under white light irradiation using a potentiostat station. Cyclic voltammetry in the presence of and without purging CO2 was also investigated. The LSV investigations showed the synergy effect between PbS thin films and Si for the rising and transport of the charge carriers. The results showed a higher photocatalytic towards CO2 reduction of PbS/SiPY compared to Silicon substrate without surface texturization and sensitization. The photoelectrode based on PbS/SiPY could efficiently be used as a photocathode for the photoelectrochemical (PEC) reduction of CO2 to Methanol. [ABSTRACT FROM AUTHOR]

Lead sulfide quantum dots (PbS QDs) are used in broadband photodetectors due to their excellent size tunability, photosensitivity, and solution processability. However, due to the risk of Ostwald ripening, synthesizing high-quality PbS QDs with absorption peaks over 2000 nm with high monodispersity is a challenge. In this study, by controlling the molar ratio of Pb to S and the number of injections of S precursor, we successfully prepared large PbS QDs with an absorption peak at 2122 nm, corresponding to an average diameter of 11.42 nm, with a super-mono-dispersity of 5.50%. Broadband photodetectors ranging from visible light to short-wave infrared are prepared using the large PbS QDs, corresponding to a response rate of 5.98 mA/W at 1940 nm. [ABSTRACT FROM AUTHOR]

In this review, the chemical bath deposition method has been studied to investigate lead sulfide thin film. The important results obtained from XRD, AFM and optical Spectrophotometer measurements were discussed. peaks patterns illustrated that the lead sulfide structure have a cubic phase nanocrystalline corresponded to the strong peaks (111) and (200) at 2θ ≅ 26.3◦ and 29.8◦ respectively. Atomic force microscope (AFM) images exhibited that the lead sulfide (PbS) thin films have a nano-size grain also the grain size increased with increasing film thickness. Different parameters such as dislocation density and internal strain have been studied to be decreased with concentration. Decreasing internal strain and dislocation density with increasing concentration show enhancement of lattice constant as prepared films Scanning electron Microscope (SEM) images displayed that the top surface layers are strongly affected depending on the nature top. The PbS structure are quite homogeneous , the size distribution was about 71–83 nm. The influence of deposition time, thickness, nature of the substrate, concentration of solution and doping on the PbS films was also discussed. It can be seen, The prepared thin film was a thinner film with a short deposition time compared to prepared samples with a longer time. It has also been found that the precipitated films show optical absorbance in the room and UV region but their absorbance decreases upon entering the near-infrared (NIR) region. Lead Sulfide thin films have gained remarkable attention worldwide due to an important narrow band gap semiconductor which has broad potential applications in optoelectronics devices.