Commercial zeolites are crystalline aluminosilicate materials with high surface area and porosity which can be used in several applications. This study aims at adding luminescent functionality to the zeolite network, either enabling optical monitoring of the capturing process or towards the development of efficient light-emitting materials. Two representative commercial zeolites were chosen: 5A and 13X, adding europium (Eu³⁺) by an ion-exchange process. The effects of different solvents (water and ethanol) and thermal treatments on the structural and optical properties of the doped zeolites were investigated. The results demonstrate that 13X zeolites have superior Eu uptake and luminescent properties compared to 5A. XRD analysis suggests that Eu exchange can stress and disorder the network, which is recovered by annealing up to 600 °C. Instead, a higher temperature of 800 °C induces the collapsing of the porosity, with partial amorphization and significant reduction of the surface area of the material. The optical analysis showed that the PL intensities for 13X samples can be 60 times higher than those obtained for 5A samples. Moreover, ethanol emerged as a superior solvent to water, avoiding the presence of -OH vibrational energies detrimental to the luminescence of rare earth ions.

Semitransparent thin film solar cells based on wide bandgap absorber Sb2S3 have immense potential in building integrated photovoltaic (BIPV) applications. A typical thin film Sb2S3 solar cell using low-cost solution-based methods (such as hydrothermal deposition) utilizes a toxic CdS film with a narrow bandgap (2.4 eV) as the electron transport layer (ETL). Wide bandgap (3.1–3.4 eV) non-toxic TiO2 meets the optoelectronic requirements for a Cd-free ETL alternative but the hydrothermal deposition of Sb2S3 on TiO2 results in a non-uniform island-like growth, which is unsuitable for semitransparent applications (utilizing less than 100 nm Sb2S3). Therefore, in this study, using the successive ionic layer adsorption and reaction (SILAR) method, an ultrathin ZnS layer (1–3 nm) is coated on TiO2 as a surface modification layer to improve the nucleation and growth characteristics of Sb2S3 during hydrothermal deposition. The introduction of ZnS results in a pinhole-free compact mirrorlike Sb2S3 film similar to that obtained on CdS. The optimized solar cells based on CdS, TiO2, and TiO2-ZnS ETLs showed photoconversion efficiencies (PCEs) of 5.2 %, 5.1 %, and 4.3 %, respectively. A comprehensive comparative study is then reported highlighting the relationship between morphology, optoelectronic properties, and photovoltaic performance of the Sb2S3 films grown on the three ETLs. Furthermore, utilizing the excellent film morphology of Sb2S3 on TiO2-ZnS ETL, semitransparent solar cells were fabricated using an ultrathin Au (<10 nm) electrode. Semitransparent solar cells using 65 and 80 nm Sb2S3 absorber layers on TiO2-ZnS obtained PCEs (and average visible transmittances, AVTs) of 3.3 % (11.2 %) and 3.6 % (8.8 %), respectively. These results are critical to the development of the BIPV sector through environmentally friendly and non-critical materials-based solutions.

In this study we present and discuss p-n heterostructures for photodetection. The hybrid structures consist of CeO2:ZnO-Cu2O, featuring different concentrations of CeO2, fabricated by using hydrothermal co-growth for CeO2 and ZnO, and sputtering deposition for Cu2O. As the concentration of CeO2 in the ZnO pristine nanorods was increased, the structural, optical and functional features of the materials showed relevant changes, in terms of crystalline domains and optical bandgap. After Cu2O deposition, the ternary materials were tested as UV photodectors, showing very good performance in terms of fast response and decay times. Specifically, we found that the CeO2:ZnO-Cu2O devices maintain a stable current under light irradiation, whose value was dependent on the CeO2 amount incorporated in the ZnO 1D nanostructures. Among all tested configurations, the 5.5 % hybrid CeO2:ZnO-Cu2O exhibits the highest current efficiency, accompanied by rapid rise and decay times. Our investigation suggests that the CeO2:ZnO-Cu2O configuration holds great potential for optoelectronic applications, particularly in the development of UV photodetectors.

Interfacial solar desalination using plasmonic metal semiconductors is a valuable process for freshwater production. However, the design of a sustainable and efficient photothermal evaporator is still challenging. In the present research, polyethylene terephthalate waste bottles were upcycled into carbon foam (CF) and further functionalized with CuS nanoflakes as a photothermal layer. Analytical characterizations (X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy, and scanning transmission electron microscopy–high-angle annular dark field) demonstrated the successful decoration of two-dimensional Covellite CuS nanoflakes on graphitic CF having microporous channels. UV/vis spectroscopy measurements show enhanced optical absorption with CuS/CF of up to 95% compared to bare CF (72%). The photothermal desalination experiment displayed an improved evaporation rate of 1.90 kg m⁻² h⁻¹ for the CuS–CF compared to 1.58 kg m⁻² h⁻¹ for the bare CF and CuS 1.41 kg m⁻² h¹, reveling the excellent water evaporation efficiency of 91%. The obtained results suggested that the design of CuS-functionalized CF derived from waste plastic for solar desalination is a useful strategy to produce fresh water from the upcycling of waste materials and a good example of circular economy through the development of engineered composite systems.

Selective oxidation of amines to imines through electrocatalysis is an attractive and efficient way for the chemical industry to produce nitrile compounds, but it is limited by the difficulty of designing efficient catalysts and lack of understanding the mechanism of catalysis. Herein, we demonstrate a novel strategy by generation of oxyhydroxide layers on two-dimensional iron-doped layered nickel phosphorus trisulfides (Ni1−xFexPS3) during the oxidation of benzylamine (BA). In-depth structural and surface chemical characterizations during the electrocatalytic process combined with theoretical calculations reveal that Ni(1−x)FexPS3 undergoes surface reconstruction under alkaline conditions to form the metal oxyhydroxide/phosphorus trichalcogenide (NiFeOOH/Ni1−xFexPS3) heterostructure. Interestingly, the generated heterointerface facilitates BA oxidation with a low onset potential of 1.39 V and Faradaic efficiency of 53% for benzonitrile (BN) synthesis. Theoretical calculations further indicate that the as-formed NiFeOOH/Ni1−xFexPS3 heterostructure could offer optimum free energy for BA adsorption and BN desorption, resulting in promising BN synthesis.

In this study, unmodified and graphene (G)-modified TiO2–CuO mixed oxide thin films were synthesized via spray pyrolysis, incorporating varying graphene content (y = 2, 4, 6, and 8 at. %). The modified samples were subjected to photocatalytic (Rhodamine B (RhB), Malachite green (MG), Methylene Blue, and Methyl Orange) and photovoltaic performance evaluations. X-ray diffraction (XRD) confirmed the formation of well-crystalline thin films, while X-ray photoelectron spectroscopy (XPS) (XPS) provided insights into the electronic states of Cu, Ti, C, and O elements. After graphene modification, the Cu 2p and Ti 2p spectra exhibited a negative and positive shift, respectively, indicating Cu reduction and Ti oxidation. Optical absorption analysis revealed an increase in band gap energy with higher graphene concentrations, reaching 1.78 eV at 6 at. % graphene content. The as-prepared samples were tested for photocatalytic degradation of organic dyes in polluted water, including Rhodamine B (RhB), Malachite Green (MG), Methylene Blue (MB), and Methyl Orange (MO). The film dropped at 8 at. % graphene demonstrated remarkable photocatalytic efficiency, achieving degradation rates of 90 %, 85 %, 96 %, and 87 % for RhB, MG, MB, and MO, respectively, within 2 h of solar illumination. Furthermore, the application of G-TiO2-CuO as a secondary absorber layer in CZTS solar cells was optimized using Silvaco TCAD software, resulting in an efficiency enhancement from 10.25 % to 15.31 %. These findings highlight the crucial role of graphene modification in enhancing the physical properties of semiconductor materials, making them promising candidates for advanced optoelectronic applications.

Environmental pollution is a complex problem that threatens the health and life of animal and plant ecosystems on the planet. In this respect, the scientific community faces increasingly challenging tasks in designing novel materials with beneficial properties to address this issue. This study describes a simple yet effective synthetic protocol to obtain nickel hexacyanoferrate (Ni-HCF) nanocubes as a suitable photocatalyst, which can enable an efficient photodegradation of hazardous anthropogenic organic contaminants in water, such as antibiotics. Ni-HCF nanocubes are fully characterized and their optical and electrochemical properties are investigated. Preliminary tests are also carried out to photocatalytically remove metronidazole (MDZ), an antibiotic that is difficult to degrade and has become a common contaminant as it is widely used to treat infections caused by anaerobic microorganisms. Under simulated solar light, Ni-HCF displays substantial photocatalytic activity, degrading 94.3% of MDZ in 6 h. The remarkable performance of Ni-HCF nanocubes is attributeto a higher ability to separate charge carriers and to a lower resistance toward charge transfer, as confirmed by the electrochemical characterization. These achievements highlight the possibility of combining the performance of earth-abundant catalysts with a renewable energy source for environmental remediation, thus meeting the requirements for sustainable development.

The urea oxidation reaction (UOR), with its low thermodynamic potential, offers a promising alternative to the oxygen evolution reaction (OER) for efficient hydrogen production. However, its sluggish kinetics still demand the development of an efficient electrocatalyst. In this study, the critical role of Ru doping in Fe₂TiO₅ is demonstrated to accelerate UOR kinetics. The computational finding confirmed the feasibility of this approach, guiding the experimental synthesis of Fe_2−xRu_xTiO₅. Benefitting from surface properties and electronic structure, the synthesized material exhibits superior performance with a potential of 1.30 V at a current density of 10 mA cm⁻² for UOR, compared to undoped Fe2TiO5 (1.40 V). Moreover, it demonstrates a favourable Tafel slope of 52 mV dec⁻¹ and maintains robust durability for 72 h. As confirmed from experimental and computational findings, the enhanced activity can be attributed to the Ru doping resulting in structural distortion at the Fe site and creation of a favourable adsorption site thereby enhancing UOR via dual active center. This study not only broadens the potential applications of Fe2TiO5-based materials beyond their traditional role as photocatalysts but also establishes them as promising electrocatalysts underscoring the versatility and improved performance of Fe_2−xRu_xTiO₅.

Luminescent solar concentrators (LSCs) as an optical device to concentrate light from large areas illuminated by sunlight into small-area photovoltaic cells, can greatly reduce the cost of solar energy generation, thus showing promise in building-integrated photovoltaics. Here, we report the synthesis of a novel type of composite nanoparticle via the simple sol-gel method. Starting from hydroxyl-rich carbon nanodots (CDs), Rhodamine B (RhB) molecules were embedded into a silica matrix shell, forming a composite core-shell system, where the CDs represent the core and RhB embedded in SiO2 are the shell of the final CDs/RhB@SiO2 structure. These nanoparticles were successfully employed in high-performance LSC fabrication. The Förster resonant energy transfer (FRET) between the CDs and the dye was successfully exploited to improve the light absorption efficiency and power conversion efficiency (ηPCE) of LSC devices. The solid-state photoluminescence quantum yield of the as-synthesized composite nanoparticles can reach ∼ 57 % due to the effective suppression of the aggregation-induced quenching. These fluorescent composite nanoparticles were used for fabricating LSC devices with an ultrahigh ηPCE of ∼ 3.8 % for 5 × 5 cm2 devices, thanks to the high loading of luminophores and effective FRET.

In the past decade, molybdenum ditelluride (MoTe2) has received significant attention from the scientific community due to its structural features and unique properties originate from them. In the current review, the properties, various preparation approaches, and versatile applications of MoTe2 are presented. The review provides a brief update on the state of our fundamental understanding of MoTe2 material and also discusses the issues that need to be resolved. To introduce MoTe2, we briefly summarize its structural, optoelectronic, magnetic, and mechanical properties in the beginning. Then, different preparation methods of MoTe2, such as exfoliation, laser treatment, deposition, hydrothermal, microwave, and molecular beam epitaxy, are included. The excellent electrical conductivity, strong optical activity, tunable bandgap, high sensitivity, and impressive stability make it an ideal contender for different applications, including energy storage, catalysis, sensors, solar cells, photodetectors, and transistors. The performance of MoTe2 in these applications is systematically introduced along with mechanistic insights. At the end of the article, the challenges and possible future directions are highlighted to further modify MoTe2 material for the numerous functionalities. Therefore, the availability of different phases and layer structures implies a potential for MoTe2 to lead an era of two-dimensional materials that began from the exfoliation of graphene.