Materials Research Bulletin最新文献

Electrochemical reduction of nitrate to ammonia is a promising method for treating nitrate-containing wastewater and synthesizing high-value-added ammonia. However, the low catalytic efficiency of electrocatalysts and the complex process of catalyst preparation hinder the practical application and development of nitrate-to-ammonia conversion. In this work, Cu rearrangement on the surface of copper foam (CF) was achieved through a surface reconstruction engineering strategy, resulting in the construction of a high-performance NO₃RR electrocatalytic electrode (Cu@CF). Benefiting from the ideal structural advantages, the performance of Cu@CF in NO₃RR was significantly improved, with NH₃ production rates reaching up to 7.9 mg h^-1 cm^-2 and a Faradaic efficiency of 92.3%. Furthermore, the zinc-nitrate fuel cell assembled with Cu@CF and zinc foil also showed excellent fuel cell performance, with an output voltage of up to 1.4 V and power density of 3.9 mW cm^-2. This study has reference value for the development of efficient, stable and inexpensive NO₃RR electrodes.

Tandem solar cells (TSC) have been introduced to better absorb the spectrum of sunlight and reduce optical loss. Among these, perovskite–organic tandem solar cells (P-OTSC) have emerged as a prominent topic over the last decade due to their complementary absorption spectrum. Additionally, incorporating diverse pigmented protein complexes in TSC fabrication is becoming more common. Natural chlorophyll-containing photosystems have garnered significant attention for their naturally solar-tuned absorption spectra. Photosystem I protein (PSI), is the most robust component of oxygenic photosynthesis and contains over 100 Chl a molecules/complex with two sharp absorbance peaks at 430 and 665 nm. PSI offers a second and complementary active layer because P-OTSCs often have a low extinction coefficient in the red wavelength region. In this research, the performance of P-OTSCs was enhanced by improving the absorption spectrum by utilizing an isolated plant PSI complex. The circuit current density (J_sc) increased from 14.23 mA/cm² to 14.95 mA/cm², and the power conversion efficiency (PCE) of P-OTSCs increased from 19.32 % to 20.24 %. We also observed that the external quantum efficiency (EQE) shows an apparent increase in the long wavelength region, reflecting the absorbance of light by PSI. This work is the first to report the integration of PSI into perovskite–organic tandem solar cells, and it motivates new design considerations that can further boost efficiency and utilize natural, earth-abundant pigment proteins.

Sulfide electrolyte-based all-solid-state lithium batteries (ASSLB) are heralded as a cornerstone for next-generation energy storage solutions, distinguished by their exceptional ionic conductivity, superior energy density, and enhanced safety features. Nonetheless, the ascendancy of sulfide-based ASSLB in augmenting energy density and elongating cycle life is curtailed by the suboptimal solid-solid interfacial contact and the compromised chemical/electrochemical stability of both the cathode and the sulfide solid electrolyte (SSE). This review dissects the quintessential challenges at the cathode-SSE interface, elucidating the underlying mechanisms contributing to elevated interfacial resistance, the formation of space charge layers, and interfacial compatibility dilemmas. It addresses the primary challenges at the cathode-SSE interface, highlighting the mechanisms behind increased interfacial resistance, chemical/electrochemical instability, and poor interfacial compatibility. It systematically explores strategies to improve the interface, including microstructure regulation, coating cathode, synthesis modification, and other treatments. Finally, it summarizes the development prospects and improvement methods of sulfide-based ASSLB.

Colloidal quantum dots (CODs) have attracted attention towards the next-generation optoelectronic devices capable of tuning the bandgap to capture photons at the UV region which is the major impediment of silicon (Si) for optoelectronic applications. However, CODs convert higher-energy photons into lower-energies photons through spectral down-conversion to UV visible. This study describes the photoconductivity effects of colloidal 3C-SiC QDs onto the underlying black silicon (b-Si) for spectral down-conversion effect. The Si showed a remarkable decrease in broadband reflectance after being etched to b-Si via metal-assisted chemical etching (MACE) over a broad spectral wavelength range of 300–1100 nm. Incorporating QDs onto underlying b-Si enhanced the device responsivity from 0.034 A/W to 0.53 A/W with the formation of space charge through the down-conversion effect. Furthermore, the photovoltaic measurements demonstrate the superior performance of hybrid colloidal 3C-Si QDs/b-Si with a power conversion efficiency (PCE) of ∼7.28 % compared to b-Si without QDs (5.57 %) photovoltaic cells. Our research provides insight into the down-conversion effects of colloidal 3C-SiC QDs for photovoltaic and photodetector applications.

The field of solar photocatalysis has been plagued by photocatalysts with low photon-to-electron conversion efficiency, resulting in poor photocatalytic degradation rates of water pollutants. With a keen idea to improve the existing photocatalysts, we developed a scavenger-free, magnetically separable, bi-junctional solar photocatalyst. The photocatalyst comprises Fe²⁺ doped zinc ferrite as core, ZnO as shell, and irregular CuO nanoparticles in conjunction with the surface of core-shell nanoparticles prepared using a combination of microwave-assisted solvothermal technique and microwave-assisted reflux method. The photocatalytic degradation properties of the solar photocatalyst were modelled and optimized with the help of Methyl Orange under direct sunlight. This novel composite degrades Methyl Orange roughly four times faster than core-shell nanoparticles. The photocatalyst meets most of the criteria for working of a promising solar photocatalyst, such as 1) excellent absorption of sunlight, 2) two physically distinct heterojunction and absorbing regions for efficient charge carrier generation and separation, 3) scavenger-free degradation of textile dyes and antibiotics, 4) High surface area (39 m²g ⁻¹), 5) good stability, 6) excellent reusability, 7) and easy separation of nanoparticles for reuse with the help of a magnet. The prepared photocatalyst efficiently degrades fluoroquinolone antibiotics such as Ciprofloxacin Hydrochloride, Norfloxacin, and Ofloxacin. The photocatalyst demonstrates the capability to efficiently degrade textile dyes such as Methyl Orange, Methylene Blue, Orange G, Fluorescein sodium salt, Rhodamine B, and Crystal Violet. Additionally, the bi-junctional photocatalyst can be coated with a thin layer of silver to achieve twice the degradation rate. This enhancement is attributed to the Localized Surface Plasmon Resonance (LSPR) effect. The current work presents an effective and economical option for removing dyes and antibiotics in wastewater, marking a significant stride towards sustainable industrial practices.

The strong photo-induced charge separation /transfer plays an essential function in improving the photocatalysis efficiency of Ag₂WO₄ nanoparticles (AWO NPs). Herein, the novel Ag₂WO₄/Co/g-C₃N₄ (ACG) nanocomposite (NCs) was fabricated via the ultrasonic and facile co-precipitation approach for the assessment of photocatalytic activity. Physiological and photoelectrochemical techniques investigated the optical characteristics, phase structures, morphology, and charge separation of pristine and ACG NCs. The crystalline nature of the fabricated nanomaterials was verified by XRD and a selected area electron diffraction (SAED) pattern. According to the optical properties of ACG NCs, the particle has a band gap energy of 2.7 eV, which allows it to break down brilliant cresyl blue (BCB) in the existence of visible light (VL). The findings show that the photocatalytic degradation performance of ACG NCs for BCB (97.46%) was greater than that of individual g-C₃N₄ nanosheets (GCN NSs) (40.4%) and AWOs (58.78%). The produced photocatalyst exhibited an outstanding performance for the BCB dye degradation and the reaction mechanism obeyed the pseudo-first-order kinetics of the Langmuir-Hinshelwood model. Through a radical trapping experiment, it was determined that the ^•OH and ^•O₂ radicals were primarily accountable for the catalytic activity involved in the degradation of BCB. Six rounds of testing were used to examine the reusability of ACG NCs, and the reusable efficiency was 93.04%. The hazardous organic contaminants found in the environmental water bodies may be rapidly eliminated with the use of the produced NCs.

One-dimensional confined nanostructures with intense dipole orientation exhibit enhanced piezoelectric performance compared to traditional three-dimensional bulk films. Herein, we show that preparing highly aligned thin polyvinylidene fluoride (PVDF) nanofibers in the presence of a small amount of organically modified clay (Cloisite 30B) platelets induces a significant crystal polymorphism alteration from non-polar α-phase to polar β-phase rather than the randomly oriented neat PVDF nanofibers with a larger average diameter. It has been detected that the nanofiber orientation considerably contributes to the enhanced degree of crystallinity and mechanical properties. Also, the PVDF-Cloisite 30B interactions caused an improvement in the elastic modulus. The piezoelectric performance of the electrospun nanofibers was examined by sensing characteristics. It was found that the synergistic effects of nanofiber orientation and clay platelets efficiently improve sensing performance via the piezoelectric dipole orientation mechanism.

To provide electromagnetic protection for intelligent equipment, advanced electromagnetic wave absorption (EWA) materials are highly desired. To reveal the interaction mechanism of structure and electromagnetic waves, polyaniline (PANI) with various structures, including nanosheets, clusters, and nanofibers, is synthesized via a template-free approach. The self-assembly process of PANI can be regulated by camphor sulfonic acid due to the formation and guidance of charge transfer complexes. A comprehensive analysis of structure, chemical constitution, and electromagnetic characteristics is conducted. Clusters with three-dimensional micro-nano structure exhibit superior microwave absorption, achieving a minimum reflection loss of −52.22 dB at 9.84 GHz with a 3.2 mm thickness and an absorption bandwidth of 6.12 GHz at 2.3 mm thickness. The outstanding EWA performance is attributed to the unique architecture, strong dielectric loss capabilities, and effective impedance matching. Moreover, the fabrication process is cost-effective and scalable, making it conducive to practical applicability.

Various organic pollutants continually poison natural water resources due to rapid modernization driven by industrial growth. As a result, communities throughout the globe are paying close attention to the health and environmental issues raised by these harmful organic pollutants. Here, we prepared TiO₂-CuO(5wt%), TiO₂-CuO(5wt%)@Co₃O₄, and TiO₂-CuO(5wt%)@Mn₂O₃ photocatalysts by employing the sol-gel method for the photocatalytic removal of azo dyes. These composites' surface morphology, composition, band gap, and purity were analyzed using SEM, EDS, TEM/HRTEM, XRD, FTIR, Raman, XPS, DRS, and BET measurements. The 5 % CuO doping caused a significant change in the electronic structure of the composites and contributed to the superior photocatalytic performance of the composites against azo dyes at neutral pH and under visible light irradiation. The function of reactive oxygen species (ROS) was also studied using different scavengers and enhancers; •OH was found to be the main ROS for the photodegradation of azo dyes.

This paper presents a photochemical synthesis method for producing pure CeO₂ deposits and CeO₂ deposits loaded with varying proportions of Fe₂O₃. The deposits were calcined at 950 °C and characterized structurally, compositionally, and morphologically using XRD, XPS, SEM, FT-IR, and Raman spectroscopy techniques. Cerianite and hematite phases were identified in CeO₂/Fe₂O₃ samples, indicating heterogeneous surface deposits. Photocatalytic testing under UV–Vis illumination for 5 h demonstrated promising results. For the degradation of bright green dye, efficiencies of 78.9 % and 90.1 % were achieved for pure CeO₂ and CeO₂ samples loaded with 1.0 mol% Fe₂O₃, respectively. Similarly, for oxytetracycline drug degradation, performance rates of 35.3 % and 67.0 % were observed for CeO₂ and CeO₂ samples loaded with 1.0 mol% Fe₂O₃, respectively. Recyclability tests showed a gradual decline in photocatalytic performance over successive cycles due to by-product accumulation contaminating the catalyst.