Search Results (24)

Copper-doped indium zinc sulfides were synthesized by heating and stirring a mixture of zinc chloride, indium chloride tetrahydrate, thioacetamide, and copper chloride at 180 °C for 18 h. Among these, Zn_5.7Cu_0.3In₂S₉ exhibited a hydrogen-producing activity of 1660 μmol/g·h, which was approximately five times higher than that of pristine indium zinc sulfide. Therefore, the catalyst was characterized to investigate the effect of Cu addition. PL results revealed that the incorporation of Cu reduced the fluorescence intensity, indicating suppressed recombination of photogenerated electron–hole pairs. DRS showed that the Cu addition enhanced optical absorption in the visible-light region and narrowed the band gap. These findings suggest that the incorporation of copper into indium zinc sulfide improves its photocatalytic activity. Full article

Herein, flower-like Zn₃In₂S₆ (ZIS₃) crystallites were grown onto acorn leaf-like CdS assemblies via a two-step hydrothermal approach. Under visible light irradiation, the Zn₃In₂S₆-enriched heterostructures demonstrated an enhanced azo-dye degradation rate, with the majority of the organic analyte (Orange G) being degraded within 60 min. In contrast, the CdS-enriched hybrids showed poor photocatalytic performance. The optimized hybrid containing a nominal CdS content of 4 wt% was characterized by various physicochemical techniques, such as XRD, SEM, XPS and Raman. XPS analysis showed that the electron density around the Zn and In sites in Zn₃In₂S₆ was slightly increased, implying a certain charge migration pattern. Complementary information from scavenging experiments suggested that hydroxy radicals were not the exclusive transient responsible for oxidative degradation of the organic azo-dye. This research provides new information about the development of metal chalcogenide-based heterostructures for efficient photocatalytic organic pollutant degradation. Full article

Photocatalytic water splitting for hydrogen production is seen as a promising solution to energy problems due to its eco-friendly and sustainable properties, which have attracted considerable interest. Despite progress, the efficiency and selectivity of solar-driven photocatalytic hydrogen generation are still below optimal levels, making it a major challenge to effectively harness solar energy for hydrogen production through photocatalytic water splitting. Advancing high-performance semiconductor photocatalysts is seen as key to tackling this issue. Zinc indium sulfide (ZnIn₂S₄) has gained attention in recent years as a promising semiconductor material for photocatalytic hydrogen production, thanks to its advantageous properties. Studies in photocatalysis are shifting toward the continuous development and modification of materials, with the goal of enhancing efficiency and extending their applications in environmental and energy fields. With proper development, the material may eventually be suitable for large-scale commercial use. Recent studies have aimed at boosting the photocatalytic hydrogen evolution (PHE) efficiency of ZnIn₂S₄-based photocatalysts through a range of experimental techniques, including surface modifications, forming semiconductor heterojunctions, doping with metals and nonmetals, defect engineering, and particle size analysis. The purpose of this review is to explain the design strategies for ZnIn₂S₄-based photocatalysts through these approaches and to provide a thorough summary of the latest developments in their role as catalysts for hydrogen production. Full article

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

Zinc indihuhium sulfide (ZIS), among various semiconductor materials, shows considerable potential due to its simplicity, low cost, and environmental compatibility. However, the influence of precursor anions on ZIS properties remains unclear. In this study, we synthesized ZIS via a hydrothermal method using four different anionic precursors (ZnCl₂/InCl₃, Zn(NO₃)₂/In(NO₃)₃, Zn(CH₃CO₂)₂/In(CH₃CO₂)₃, and Zn(CH₃CO₂)₂/In₂(SO₄)₃), resulting in distinct morphologies and crystal structures. Our findings reveal that ZIS produced from Zn(CH₃CO₂)₂/In₂(SO₄)₃ (ZIS-AceSO₄) exhibited the highest photocatalytic CO₂ reduction efficiency, achieving a CO production yield of 134 μmol g⁻¹h⁻¹. This enhanced performance is attributed to the formation of more zinc and indium vacancy defects, as confirmed by EDS analysis. Additionally, we determined the energy levels of the valence band maximum (VBM) and the conduction band minimum (CBM) via UPS and absorption spectra, providing insights into the band alignment essential for photocatalytic processes. These findings not only deepen our understanding of the anionic precursor’s impact on ZIS properties but also offer new avenues for optimizing photocatalytic CO₂ reduction, marking a significant advancement over previous studies. Full article

The high electrons and holes recombination rate of ZnIn₂S₄ significantly limits its photocatalytic performance. Herein, a simple in situ photodeposition strategy is adopted to introduce the cocatalyst cobalt phosphate (Co-Pi) on ZnIn₂S₄, aiming at facilitating the separation of electron–hole by promoting the transfer of photogenerated holes of ZnIn₂S₄. The study reveals that the composite catalyst has superior photocatalytic performance than blank ZnIn₂S₄. In particular, ZnIn₂S₄ loaded with 5% Co-Pi (ZnIn₂S₄/5%Co-Pi) has the best photocatalytic activity, and the H₂ production rate reaches 3593 μmol·g⁻¹·h⁻¹, approximately double that of ZnIn₂S₄ alone. Subsequent characterization data demonstrate that the introduction of the cocatalyst Co-Pi facilitates the transfer of ZnIn₂S₄ holes, thus improving the efficiency of photogenerated carrier separation. This investigation focuses on the rational utilization of high-content and rich cocatalysts on earth to design low-cost and efficient composite catalysts to achieve sustainable photocatalytic hydrogen evolution. Full article

Timely diagnosis and appropriate antitumoral treatments remain of utmost importance, since cancer remains a leading cause of death worldwide. Within this context, nanotechnology offers specific benefits in terms of cancer therapy by reducing its adverse effects and guiding drugs to selectively target cancer cells. In this comprehensive review, we have summarized the most relevant novel outcomes in the range of 2010–2023, covering the design and application of nanosystems for cancer therapy. We have established the general requirements for nanoparticles to be used in drug delivery and strategies for their uptake in tumor microenvironment and vasculature, including the reticuloendothelial system uptake and surface functionalization with protein corona. After a brief review of the classes of nanovectors, we have covered different classes of nanoparticles used in cancer therapies. First, the advances in the encapsulation of drugs (such as paclitaxel and fisetin) into nanoliposomes and nanoemulsions are described, as well as their relevance in current clinical trials. Then, polymeric nanoparticles are presented, namely the ones comprising poly lactic-co-glycolic acid, polyethylene glycol (and PEG dilemma) and dendrimers. The relevance of quantum dots in bioimaging is also covered, namely the systems with zinc sulfide and indium phosphide. Afterwards, we have reviewed gold nanoparticles (spheres and anisotropic) and their application in plasmon-induced photothermal therapy. The clinical relevance of iron oxide nanoparticles, such as magnetite and maghemite, has been analyzed in different fields, namely for magnetic resonance imaging, immunotherapy, hyperthermia, and drug delivery. Lastly, we have covered the recent advances in the systems using carbon nanomaterials, namely graphene oxide, carbon nanotubes, fullerenes, and carbon dots. Finally, we have compared the strategies of passive and active targeting of nanoparticles and their relevance in cancer theranostics. This review aims to be a (nano)mark on the ongoing journey towards realizing the remarkable potential of different nanoparticles in the realm of cancer therapeutics. Full article

Low isolation efficiency of photogenerated electron-hole pairs and inadequate utilization of visible light limit the application of g-C₃N₄ nanosheets (CNNs) in photocathodic protection (PCP). Therefore, indium zinc sulfide (ZnIn₂S₄, ZIS) nanolayers with nano-leaf structures were fabricated on CNNs using a simple hydrothermal method and used as visible light sensitizer and electron donor to improve its PCP performance. Under visible light illumination, the 30% ZIS@CNNs photoelectrode coupled with 316 stainless steel (SS) exhibited the largest photocurrent density of 17.30 μA cm⁻² and the highest potential drop of 0.37 V, which was approximately 4 and 7.5 times higher than that of pure CNNs, respectively. The improvement in protection performance may be attributable to the crucial increase in visible light absorption and the terrific enhancement in rapid migration pathways provided using heterogeneous junctions. Full article

Photocatalytic degradation plays a crucial role in wastewater treatment, and the key to achieving high efficiency is to develop photocatalytic systems that possess excellent light absorption, carrier separation efficiency, and surface-active sites. Among various photocatalytic systems, S-type heterojunctions have shown remarkable potential for efficient degradation. This work delves into the construction of S-type heterojunctions of ternary indium metal sulfide and bismuth ferrite nanofibers with the introduction of sulfur vacancy defects and morphology modifications to enhance the photocatalytic degradation performance. Through the impregnation method, BiFeO₃/ZnIn₂S₄ heterojunction materials were synthesized and optimized. The 30% BiFeO₃/ZnIn₂S₄ heterojunction exhibited superior photocatalytic performance with higher sulfur vacancy concentration than ZnIn₂S₄. The in-situ XPS results demonstrate that the electrons between ZnIn₂S₄ and BFO are transferred via the S-Scheme, and after modification, ZnIn₂S₄ has a more favorable surface morphology for electron transport, and its flower-like structure interacts with the nanofibers of BFO, which has a further enhancement of the reaction efficiency for degrading pollutants. This exceptional material demonstrated a remarkable 99% degradation of Evans blue within 45 min and a significant 68% degradation of ciprofloxacin within 90 min. This work provides a feasible idea for developing photocatalysts to deal with the problem of polluted water resources under practical conditions. Full article

During the last few decades, major advances have been made in photovoltaic systems based on Cu(In,Ga)Se₂ chalcopyrite. However, the most efficient photovoltaic cells are processed under high-energy-demanding vacuum conditions. To lower the costs and facilitate high-throughput production, printing/coating processes are proving to be effective solutions. This work combined printing, coating, and chemical bath deposition processes of photoabsorber, buffer, and transparent conductive layers for the development of solution-processed photovoltaic systems. Using a sustainable approach, all inks were formulated using water and ethanol as solvents. Screen printing of the photoabsorber on fluorine-doped tin-oxide-coated glass followed by selenization, chemical bath deposition of the cadmium sulfide buffer, and final sputtering of the intrinsic zinc oxide and aluminum-doped zinc oxide top conductive layers delivered a 6.6% maximum efficiency solar cell, a record for screen-printed Cu(In,Ga)Se₂ solar cells. On the other hand, the all-non-vacuum-processed device with spray-coated intrinsic zinc-oxide- and tin-doped indium oxide top conductive layers delivered a 2.2% efficiency. The given approaches represent relevant steps towards the fabrication of sustainable and efficient Cu(In,Ga)Se₂ solar cells. Full article

Photocatalytic overall water splitting in solar–chemical energy conversion can effectively mitigate environmental pollution and resource depletion. Stable ternary metal indium zinc sulfide (ZnIn₂S₄) is considered one of the ideal materials for photocatalytic overall water splitting due to its unique electronic and optical properties, as well as suitable conduction and valence band positions for suitable photocatalytic overall water splitting, and it has attracted widespread researcher interest. Herein, we first briefly describe the mechanism of photocatalytic overall water splitting, and then introduce the properties of ZnIn₂S₄ including crystal structure, energy band structure, as well as the main synthetic methods and morphology. Subsequently, we systematically summarize the research progress of ZnIn₂S₄-based photocatalysts to achieve overall water splitting through modification methods such as defect engineering, heterostructure construction, and co-catalyst loading. Finally, we provide insights into the prospects and challenges for the overall water splitting of ZnIn₂S₄-based photocatalysts. Full article

Zinc indium sulfide (ZnIn₂S₄), as a significant visible-light-responsive photocatalyst, has become a research hotspot to tackle energy demand and environmental issues owing to its excellent properties of high stability, easy fabrication, and remarkable catalytic activity. However, its drawbacks, including low utilization of solar light and fast photoinduced charge carriers, limit its applications. Promoting the response for near-infrared (NIR) light (~52% solar light) of ZnIn₂S₄-based photocatalysts is the primary challenge to overcome. In this review, various modulation strategies of ZnIn₂S₄ have been described, which include hybrid with narrow optical gap materials, bandgap engineering, up-conversion materials, and surface plasmon materials for enhanced NIR photocatalytic performance in the applications of hydrogen evolution, pollutants purification, and CO₂ reduction. In addition, the synthesis methods and mechanisms of NIR light-driven ZnIn₂S₄-based photocatalysts are summarized. Finally, this review presents perspectives for future development of efficient NIR photon conversion of ZnIn₂S₄-based photocatalysts. Full article

The primary purpose of recent research on solar cells is to achieve a higher power conversion efficiency with stable characteristics. To push the developments of photovoltaic (PV) technology, tandem solar cells are being intensively researched, as they have higher power conversion efficiency (PCE) than single-junction cells. Perovskite solar cells (PSCs) are recently used as a top cell of tandem solar cells thanks to their tunable energy gap, high short circuit current, and low cost of fabrication. One of the main challenges in PSCs cells is the stability issue. Carbon perovskite solar cells (CPSCs) without a hole transport material (HTM) presented a promising solution for PSCs’ stability. The two-terminal monolithic tandem solar cells demonstrate the commercial tandem cells market. Consequently, all the proposed tandem solar cells in this paper are equivalent to two-terminal monolithic tandem devices. In this work, two two-terminal tandem solar cells are proposed and investigated using the SCAPS-1D device simulator. Carbon perovskite solar cell (CPSC) without hole transport material (HTM) is used as the top cell with a new proposed gradient doping in the perovskite layer. This proposal has led to a substantial enhancement of the stability issue known to be present in carbon perovskite cells. Moreover, a higher PCE, exceeding 22%, has been attained for the proposed CPSC. Two bottom cells are examined, Si and CIGS-GeTe solar cells. The suggested CPSC/Si and CPSC/CIGS-GeTe tandem solar cells have the advantage of having just two junctions, which reduces the complexity and cost of solar cells. The performance parameters are found to be improved. In specific, the PCEs of the two proposed cells are 19.89% and 24.69%, respectively. Full article

The application of semiconductor photocatalysts with narrow band gaps is hindered by the rapid recombination of electron–hole pairs and limitation of multiple reactive oxygen species (ROS) synchronous generation. A n–n-type direct Z-scheme heterostructured photocatalyst was constructed based on the staggered band alignment of bismuth tungstate (Bi₂WO₆) and indium zinc sulfide (ZnIn₂S₄) to reveal the synergistic effect of charge separation and multiple ROS synchronous generation on boosting photocatalytic performance. Under irradiation, electrons in the conduction band (CB) of Bi₂WO₆ and holes in the valence band (VB) of ZnIn₂S₄ recombined at interface to prolong the lifetime of electrons in the CB of ZnIn₂S₄ and holes in the VB of Bi₂WO₆. Meanwhile, the multiple ROS synchronously generated to oxidize pollutant due to the strong redox ability of electrons of ZnIn₂S₄ and holes of Bi₂WO₆, which was determined by the CB potential of ZnIn₂S₄ and VB potential of Bi₂WO₆. The results provided valuable insights for the application of photocatalysts with a narrow band gap in the field of water pollution control. Full article

Quantum dots (QDs) have outstanding optical properties such as strong fluorescence, excellent photostability, broad absorption spectra, and narrow emission bands, which make them useful for bioimaging. However, cadmium (Cd)-based QDs, which have been widely studied, have potential toxicity problems. Cd-free QDs have also been studied, but their weak photoluminescence (PL) intensity makes their practical use in bioimaging challenging. In this study, Cd-free QD nanoprobes for bioimaging were fabricated by densely embedding multiple indium phosphide/zinc sulfide (InP/ZnS) QDs onto silica templates and coating them with a silica shell. The fabricated silica-coated InP/ZnS QD-embedded silica nanoparticles (SiO₂@InP QDs@SiO₂ NPs) exhibited hydrophilic properties because of the surface silica shell. The quantum yield (QY), maximum emission peak wavelength, and full-width half-maximum (FWHM) of the final fabricated SiO₂@InP QDs@SiO₂ NPs were 6.61%, 527.01 nm, and 44.62 nm, respectively. Moreover, the brightness of the particles could be easily controlled by adjusting the amount of InP/ZnS QDs in the SiO₂@InP QDs@SiO₂ NPs. When SiO₂@InP QDs@SiO₂ NPs were administered to tumor syngeneic mice, the fluorescence signal was prominently detected in the tumor because of the preferential distribution of the SiO₂@InP QDs@SiO₂ NPs, demonstrating their applicability in bioimaging with NPs. Thus, SiO₂@InP QDs@SiO₂ NPs have the potential to successfully replace Cd-based QDs as highly bright and biocompatible fluorescent nanoprobes. Full article