Materials Advances最新文献

Correction for ‘Exploring 2D hexagonal WO₃/COK-12 nanostructures for efficient humidity detection’ by Bhavna Rohilla et al., Mater. Adv., 2023, 4, 5785–5796, https://doi.org/10.1039/D3MA00691C.

The rational design of self-assembling protein nanocages holds great promise for synthetic biology, biotechnology and biomedical applications. Protein nanocages are well-defined nanoparticles with an inner cavity formed by self-assembly of repetitive protein building blocks. These cavities can be tailored to encapsulate and protect cargo molecules such as drugs, enzymes, or imaging agents. The ability to design de novo protein cages has recently been revolutionized by new concepts of modular protein design, computational design of interacting surfaces and machine learning-based generative protein design. Protein cages can be designed in diverse architectures and sizes, and their assembly and disassembly can be regulated by chemical, biological, and physical signals. Here, we focus on the review of engineering strategies for the designed protein cages based on coiled coils or other modular protein domains, their functionalization and opportunities of customized engineered protein cages.

A composite series, (1 − x)ZnBi₂O₄/x-BiOBr, was synthesized using a two-step hydrothermal method. The x = 0.7 composite demonstrated 100% removal of RhB in 10 minutes (k = 0.2317 min⁻¹) under visible light, ∼74 times higher than that of ZnBi₂O₄ (k = 0.0031 min⁻¹). For Orange G, x = 0.7 yielded 100% removal in 30 min with k = 0.1053 min⁻¹, ∼14 times greater than that of ZnBi₂O₄. The improved activity correlates with high S_BET (21.8 m² g⁻¹) and good interfacial charge separation. Band-edge estimates and scavenger tests suggested a type-II-like band alignment. Moreover, the x = 0.7 composite retained ≥81% of activity over 5 cycles.

The third-generation semiconductor, silicon carbide (SiC), has become increasingly crucial in emerging markets for radio-frequency and power electronic devices due to its superior physical properties. However, the insufficient growth thickness and low powder source utilization rate still limit the development of physical vapor transport (PVT) growth. In this work, a systematic investigation on the evolution progress and consumption features of the SiC powder source in PVT growth was conducted by theoretical simulations and experimental measurements. We found that the non-uniform source consumption and recrystallization negatively impacted the evolution of thermal and flow fields, resulting in a final low utilization rate of the powder source. To enhance the usage of the powder source and the quality of as-grown crystals, we designed a porous graphite plate in the PVT chamber to modulate both mass transfer processes and the thermal field. Compared to a conventional structure, the designed porous graphite plate could optimize the utilization rate (29% enhanced) and the spatial uniformity of source consumption, thereby increasing the crystal growth rates by 33%. Meanwhile, this designed plate could reduce the thermal stress gradients and thus reduce the defect density (52%) within the SiC crystals.

A CuBi₂O₄ photocathode with interconnected nanoparticle textured morphology has achieved a photocurrent density of −0.94 mA cm⁻² at 0.52 V vs. RHE. It was successfully fabricated via electrodeposition using ethylene glycol (EG) containing a specific concentration of Bi(NO₃)₃·5H₂O and CuCl₂·2H₂O as the electrolyte, followed by 2 h of calcination at 550 °C. Using urea as a complexing agent in the EG electrolyte enhanced the photocurrent density of the CuBi₂O₄ photocathode. Adding 0.15 g of urea to the electrodeposition solution improved film uniformity, enhanced PEC water splitting efficiency, and achieved a photocurrent density of −1.44 mA cm⁻² at 0.52 V vs. RHE. This value is higher than those of previously reported CuBi₂O₄ photocathodes, which typically exhibit photocurrent densities below −1.0 mA cm⁻². To understand the factors contributing to this enhanced PEC performance, this study investigated the effects of varying urea concentrations (0, 0.1, 0.15, and 0.2 g per 100 mL EG) on the crystallite domain size, morphology, surface roughness, light absorption, band gap, electronic band structure, and PEC performance. A mechanism was proposed to account for the long-term stability based on its inadequate valence band potential and irreversible degradation behaviour. This work provides insights for optimizing CuBi₂O₄ thin films to enhance their stability and efficiency in PEC water splitting applications.

In this study, a comprehensive dual-junction (n-MoS₂/p-CuO/Si and p-CuO/n-Si) evaluation of a self-biased heterostructure was conducted for photodetector applications. Owing to the integration of both junctions, the proposed design offered dual-response functionality, under zero bias, corresponding to the visible (625 nm) and NIR (720 and 808 nm) regions. At zero applied bias, the n-MoS₂/p-CuO/Si heterojunction exhibited a responsivity (R_λ) of 21.04/30.50 mA W⁻¹ and a detectivity (D*) of 1.0 × 10¹⁴/1.5 × 10¹⁴ Jones at incident wavelengths of 625/720 nm; this highlights the self-biased nature of the fabricated design. The attained values were found to be dramatically increased under a 3 V bias, with R₂ values of 0.144 and 0.124 A/W for the n-MoS₂/p-CuO/Si and p-CuO/n-Si heterostructures, respectively. The observed figures-of-merit consistently reduced as the incident light intensity increased, indicating a strong negative correlation, which was further confirmed by the R² value approaching unity (R² = 1). The time-resolved features confirmed response/recovery times of 0.27/0.36 and 0.41/0.48 s, respectively, for the addressed heterostructures, highlighting the suitability of this design for efficient, bias-free photodetection over Vis-NIR wavelengths.

Here, we present a novel materials-based strategy that bypasses alignment procedures by integrating ZnO nanoparticles into an LCE ink, enabling a simplified, direct-write 4D printing process. We first demonstrate that ZnO doping significantly enhances the photo-actuation of non-aligned, injected LCE films, confirming the viability of the approach. Applying this strategy, we successfully printed reproducible actuators that exhibit large-amplitude bending and high actuation speeds, with performance comparable to traditionally aligned LCEs. The mechanism behind this enhancement is a synergistic photo-thermal effect; the ZnO nanoparticles increase light absorption via scattering while also dramatically improving the thermal diffusivity of the polymer matrix, leading to a more efficient and rapid mechanical response. By shifting the complexity from the manufacturing process to the material itself, this work offers a scalable pathway towards the rapid fabrication of complex, stimuli-responsive architectures for applications in soft robotics and adaptive systems.

The use of luminescent tracers in plastic recycling presents a novel application opportunity for classical phosphor materials, such as co-doped YPO₄. In this study, we report the optimization of the photoluminescence quantum yield (PLQY) of YPO₄:Yb³⁺/Er³⁺ phosphors via a flux-assisted solid-state synthesis approach. Upon excitation of Yb³⁺ ions at 940 or 980 nm, efficient energy transfer to Er³⁺ ions enables strong emission at 1540 nm, with a maximum PLQY of 78% achieved under optimized synthesis conditions. This performance was obtained by annealing the phosphor at 1100 °C for 12 h in the presence of LiCl flux. Notably, a reduced synthesis temperature of 1000 °C and a much shorter annealing time of 3 h still yielded a high PLQY (72%) when the flux was present. To demonstrate practical applicability, the phosphors were integrated into two model systems: (1) dispersion of 300 ppm phosphor in transparent silicone (emulating a bulk polymer), and (2) surface printing on polyethylene foil with a loading of 10 µg cm⁻² (emulating a label). In both cases, the measured brightness was significantly lower than that of a commercial Y₂O₂S:Yb³⁺/Er³⁺ phosphor, despite its much lower PLQY of only 7%. This discrepancy was attributed to the non-optimal particle size distribution of the YPO₄ phosphor, which induced non-optimal scattering, absorption, and emission losses in both demonstrator matrices. After optimizing particle size via dry milling, the luminescence performance of the YPO₄-based phosphor surpassed that of the commercial reference in both configurations, confirming its suitability for use in luminescent tagging of plastics.

Silicon (Si) is a high-capacity anode material for lithium-ion batteries; however, its large volume change during cycling causes severe mechanical degradation. We show that optimizing the delithiation cut-off voltage effectively suppresses interfacial delamination in Si thin-film anodes. By limiting delithiation at 0.6 V, partial Li retention reduces interfacial stress and prevents structural collapse, achieving 92% capacity retention (2200 mAh g⁻¹) after 100 cycles. Cross-sectional analyses confirmed suppressed shrinkage and strong adhesion to the substrate. This simple voltage-control strategy provides a universal and practical route to enhance the durability of Si-based and other alloy-type anodes.

The confluence of metal–organic frameworks (MOFs) and conductive materials has revolutionized gas sensing technology. This study presents a synergistic composite of MIL-101(Cr) and reduced graphene oxide (rGO) for enhanced ammonia gas sensing. rGO–MIL-101(Cr) composites with varying weight percentages of MIL-101(Cr) were synthesized and further characterised using various techniques. By harnessing the exceptional surface area and tailored pore structure of MIL-101(Cr) in tandem with the superior conductivity of rGO, the composite exhibits remarkable sensitivity and fast response times. Among the prepared compositions, rGO–20 wt% MIL-101 (Cr) has demonstrated exceptional sensitivity towards ammonia detection, with a sensitivity of −18.87 for 60 000 ppm and −5.24% for 2000 ppm of ammonia gas and a discernible response at concentrations as low as 1 ppm. Notably, the composite's response remained remarkably consistent and stable, even after one year. This outstanding durability and stability underscore the composite's potential for reliable and long-term ammonia sensing applications. At this percentage, the highest sensitivity is due to the perfect coordination bonding between ammonia molecules and the chromium nodes in MIL-101(Cr), modulating its electrical properties. The formation of a perfect interface between MIL-101 (Cr) and rGO facilitates efficient charge transport, thereby enabling precise detection of ammonia gas. The FE-SEM and TEM analyses clearly show the presence of such an interface. Notwithstanding the comparable or superior sensing capabilities of existing ammonia sensors under optimal conditions, their practical utility is frequently compromised by the susceptibility of the constituent materials to humidity. In contrast, our rGO–MIL-101(Cr) composite exhibits a unique synergy of outstanding sensing performance and notable stability under moist conditions due to its remarkably high surface area and durable architecture. This exclusive combination of properties enables our material to surpass the performance of existing sensors in real-world settings, where moisture is a common factor, and thus offers a significant advantage over existing sensors. This research highlights the potential of MOF-based composites for advanced gas sensing applications, paving the way for further exploration and development of novel sensing platforms.