Materials Advances最新文献

Activated carbon (AC), generally synthesized from fossil fuels or biomass waste, is a crucial form of porous carbon used for the purification of gases and liquids. Its key performance metrics vary widely when produced from biomass because of the differing amounts of cellulose, hemicellulose, lignin, and mineral/ash content. In this study, we adapted the Aqueous Lignin Purification using Hot Agents (ALPHA) process, originally developed for purifying lignin-rich waste streams, to control the sugars (as cellulose/hemicellulose) and mineral/ash content of a given biomass. Biomass samples having a wide range of sugars (0.01–56 wt%) and mineral/ash compositions (0.01–7.1 wt%) were generated from a single, hybrid poplar cultivar and used to create AC using ZnCl₂-impregnation and low-temperature carbonization. Strong correlations were developed between the biomass sugars and mineral/ash composition and the AC surface area, pore size, and pore distribution, with the maximum surface area of 2500 m² g⁻¹ being obtained from the precursor with the highest level (56 wt%) of sugars. These findings may provide a path to predicting the properties of AC from biomasses encompassing a wide range of compositions, and furthermore, select AC precursors for target applications.

A family of biologically active novel zinc(II) compounds, namely [Zn(ahpa)(Cl)(H₂O)] (1), [Zn(ahpa)(NO₃)(H₂O)] (2) and [Zn(ahpa)(H₂O)₂](ClO₄) (3), of an anthracene-appended multifunctional organic scaffold, Hahpa (Hahpa = 3-((anthracene-10-ylmethyl)(2-hydroxyethyl)amino)propanoic acid), were synthesized and characterized. Synthesis of 1–3 was accomplished by reacting Hahpa with zinc(II) precursors such as ZnCl₂, Zn(NO₃)₂·6H₂O and Zn(ClO₄)₂·6H₂O, respectively, in the presence of NaOH at room temperature. Compounds 1–3 were characterized by elemental analysis, FTIR, electronic absorption and emission spectroscopy, molar conductivity analysis, and TGA studies. Elemental analysis, molar conductivity analysis, and UV-vis and fluorescence titration results unambiguously confirm the integrity of the compound frameworks. Moreover, the structures of 1–3 were ascertained by density functional theory (DFT) computation using the B3LYP/6-311G level of theory, indicating a distorted square pyramidal geometry around the zinc centers. Furthermore, the anticancer properties of 1–3 were assessed in human cervical cancer (HeLa) cell lines, revealing a significantly high cytotoxicity with IC₅₀ values ranging from 1.09 to 2.11 μM. They showed high selectivity between the normal and cancer cells despite this potency. The anticancer activity of 1–3 was possibly due to an increase in cellular reactive oxygen species (ROS), destruction of cell membrane integrity, and DNA damage occurring via nuclear condensation. Electronic absorption spectroscopy, ethidium bromide (EB) displacement assay and circular dichroism (CD) spectroscopy confirmed the binding affinity and binding mode of 1–3 with DNA in a dose-dependent manner. All three compounds were also able to modulate the expression of p53 tumour suppressor protein and exhibited antitumorigenic activity, whereas their activity remained unaltered in the normal cell. When a comparative assessment of anticancer properties of 1–3 was made, 1 showed a higher cytotoxicity towards the cancer cells in comparison to 2 and 3.

A major challenge in the commercialization of perovskite solar cells (PSCs) is the presence of toxic metals, like lead, in their composition. Compared with conventional lead halide perovskites, double halide perovskites have garnered significant interest owing to their reduced toxicity, adjustable bandgap, structural flexibility, and enhanced stability. This study focuses on evaluating a lead-free Cs₂BiAgI₆-double perovskite solar cell (DPSC) using a one-dimensional solar cell capacitance simulator (SCAPS-1D) with a bilayer ZnO/AZO electron transport layer (ETL) and ZnO ETL, along with various hole transport layers (HTLs) for the first time. The selected HTLs included CBTS, Cu₂O, CuAlO₂, CZTS, CuSCN, spiro-OMeTAD, MoO₃, and V₂O₅. Various factors, such as energy band alignment, recombination and generation rates, absorber thickness, defect and doping densities for all layers, energy levels of ETLs and HTL, interfacial defect densities, back metal contact, and operating temperature, were examined for improving the performance of DPSC. This study was aimed at enhancing the efficiency and deepening our understanding of the electron transport mechanisms in Cs₂BiAgI₆-DPSCs. The research findings suggested that V₂O₅ and ZnO/AZO were the most suitable materials for the HTL and ETL, respectively, among the various options considered. Therefore, we utilized ITO/ZnO/AZO/Cs₂BiAgI₆/V₂O₅/Au as the required DPSC. To boost the performance of the DPSC, electron–hole pair handling at the ETL/perovskite interface was optimized by adding a 10 nm AZO UTL, thereby enhancing the ZnO/double perovskite interface properties. The bilayer structure of ZnO/AZO offered advantages such as efficient electron extraction and minimal interfacial recombination owing to its enhanced energy level alignment and defect passivation. After optimizing these parameters, the system with the ZnO/AZO bilayer ETL achieved an efficiency of 27.20%, along with a V_oc of 1.3221 V, J_sc of 23.84 mA cm⁻², and FF of 86.28%. Thus, this work presents a straightforward and promising approach for fabricating photovoltaic devices, particularly for various types of double perovskites, with favorable charge transport layers and recombination properties. Furthermore, these findings offer theoretical guidance to improve the efficiency of Cs₂BiAgI₆-based photovoltaic solar cells (DPSCs) and facilitate the widespread adoption of eco-friendly and stable perovskites.

In this work, we investigate the impact of Bi³⁺ doping on the luminescence properties of Eu³⁺-activated NaYb(MoO₄)₂ phosphors synthesized via the conventional solid-state reaction method. Rietveld refinement of X-ray diffraction data confirmed the tetragonal crystal structure (space group I4₁/a) for all samples. UV-visible absorption spectroscopy revealed an indirect bandgap of approximately 3.25 eV for the 5% Bi³⁺-doped sample. Under UV excitation, intense red emissions originating from the ⁵D₀ → ⁷F transitions of Eu³⁺ ions were observed at 589 nm, 613 nm, 652 nm, and 700 nm, along with near-infrared emission from Yb³⁺ at 997 nm, sensitized by the MoO₄²⁻ group. Photoluminescence (PL) analysis demonstrated an enhancement in the Eu³⁺ emission intensity with increasing Bi³⁺ concentration, reaching an optimum at 5% Bi³⁺ doping. Chromaticity coordinates confirmed a significant enhancement in the red emission intensity upon Bi³⁺ incorporation. Judd–Ofelt parameters and crystal field parameters were determined, revealing that Bi³⁺ doping influences the local environment of Eu³⁺ ions, impacting the luminescence properties. Furthermore, we explored the potential of Bi³⁺/Eu³⁺ codoped NaYb(MoO₄)₂ for optical thermometry based on the fluorescence intensity ratio (FIR) technique, achieving a high relative sensitivity (S_r = 1.14% K⁻¹). This work demonstrates the influence of Bi³⁺ doping on the luminescence properties of Eu³⁺ in NaYb(MoO₄)₂ and explores its potential for applications in temperature sensing and other optoelectronic devices.

The sustainable production of hydrogen fuel through biomass-derived ethanol valorization is directly dependent on the availability of eco-friendly and efficient electrocatalysts for possible real-world end-uses. To this aim, graphitic carbon nitride (gCN) supported on flexible carbon cloths via electrophoretic deposition was functionalized with nano- and ultra-dispersed ZnO and ZnFe₂O₄ co-catalysts by cold plasma sputtering. The developed materials were tested for the first time as electrocatalysts for the ethanol oxidation reaction (EOR) in alkaline media, paving the way to the implementation of promising and inexpensive noble metal-free systems for green energy generation.

The increasing demand for advanced materials with multifunctional magnetic properties has sparked growing interest in rare-earth and transition metal-based double perovskites. In this study, we comprehensively investigate disordered Y₂CoCrO₆ (YCCO), synthesized via the sol–gel method. Structural analysis confirms a single-phase orthorhombic crystal structure with B-site disorder, as revealed by X-ray photoelectron spectroscopy, which also identifies mixed valence states of Co and Cr due to antisite disorder and oxygen vacancies. This structural disorder profoundly impacts YCCO′s magnetic properties, leading to the emergence of a Griffiths-like phase, detected through inverse susceptibility measurements. Additionally, the material exhibits both antiferromagnetic and weak ferromagnetic behaviors, evidenced by a negative Curie–Weiss temperature and unsaturated magnetic hysteresis loops. Arrott plot analysis indicates a second-order phase transition and magnetocaloric measurements reveal a maximum entropy change (S_max) of 0.217 J kg⁻¹ K⁻¹, a relative cooling power (RCP) of 17.36 J kg⁻¹, and a temperature averaged entropy change (TEC) of 0.17 J kg⁻¹ K⁻¹ over a temperature span (T_lift) of 30 K under a 5 T field, showcasing its potential for low-temperature and multistage cooling applications. Although its modest magnetocaloric effect (MCE) performance is attributed to its antiferromagnetic nature with weak ferromagnetic contributions and a low Curie temperature, this work represents a significant step in unveiling the potential of YCCO for multifunctional applications. Future optimization through chemical doping, nanostructuring, and compositional modifications is proposed to enhance its magnetocaloric and functional properties, positioning YCCO as a strong candidate for advanced magnetic and cooling technologies.

Retraction of ‘Influence of carbon additions on microstructures and mechanical properties in additive manufactured superalloys’ by Mingjun Xie et al., Mater. Adv., 2023, 4, 4897–4911, https://doi.org/10.1039/D3MA00370A.

Correction for ‘White light emission and superior color stability in a single-component host with exceptional eminent color rendering and theoretical calculations on D_uv for color quality’ by Wasim Ullah Khan et al., Mater. Adv., 2024, 5, 9851–9861, https://doi.org/10.1039/D4MA00937A.

The rare-earth-free magnetic material α′′-Fe₁₆N₂ is known to be a high-performance magnetic material. However, a synthetic route for high-yield α′′-Fe₁₆N₂ powder has not yet been established. In this study, a high-yield α′′-Fe₁₆N₂ submicron-sized powder was synthesized from Fe₃O₄via H₂ reduction, and subsequent nitridation using a CaH₂ drying agent. Here, controlling the crystallite diameter of α-Fe is crucial to promoting nitridation. α-Fe powder with a crystallite diameter of approximately 20 nm was produced by lowering the reduction temperature and water vapor partial pressure. Thus, a high-yield α′′-Fe₁₆N₂ phase of 97 wt% could be obtained. Microstructural observations indicated that α′′-Fe₁₆N₂ submicron-sized powder with primary particles of 20–30 nm diameter could be synthesized. The α′′-Fe₁₆N₂ powder had much higher coercivity than that of the α-Fe powder. Thus, the process suggested in this study is expected to contribute to the development of applications of α′′-Fe₁₆N₂ in magnetic materials.

Antibiotic pollution poses a significant threat to global health and ecosystems. It is highly demanding to detect the trace amounts of antibiotics in food and biological samples. Thus, there is a critical need for rapid and sensitive sensors with real-time monitoring capabilities to address this challenge. In this regard, porous materials such as metal–organic frameworks (MOFs) with unique and tailorable properties can serve as highly sensitive sensors for the detection of targeted analytes. Here, a new two-dimensional cobalt MOF (2D-Co MOF) has been designed and studied for the detection of nitrofurazone (NFZ), a nitrofuran class antibiotic. The 2D-Co MOF sensor demonstrates exceptional sensitivity in detecting NFZ, achieving a remarkably low detection limit of 0.04 μM. The MOF system also displayed excellent selectivity towards NFZ in the presence of potential interferants, thus acting as a potent sensor for the detection of NFZ. Additionally, the sensor exhibits excellent reliability and stability. To further demonstrate the practical applicability, the MOF sensor has been explored for the detection of NFZ drug residues in food and biological samples.