ACS Materials Letters最新文献

It is well established that semiconductor materials are crucial in modern technologies. Technological breakthroughs are achievable mainly through alteration of the properties of semiconducting materials by doping. Doping in semiconductors can be accomplished by multiple techniques. Every method possesses its own merits and drawbacks. Typically, most doping techniques affect the structure of the semiconducting material due to the impact of the doping atom during the doping procedure. This profoundly affects the characteristics of the semiconducting material. To tackle these issues, an innovative approach has recently been employed for doping semiconducting materials based on the differences in the work function among these materials. This technique is commonly referred to as “surface transfer doping”. This Review begins with a discussion of the theory underlying the surface transfer doping process, followed by an examination of its significant impact on the properties of semiconductors.

Quantum dot light-emitting diodes (QLEDs), as an emergent display technology, have garnered considerable interest due to their outstanding luminescent characteristics. Among various strategies to improve device performance, the localized surface plasmon resonance (LSPR) effect has been demonstrated as a promising approach. However, previously reported LSPR-enhanced green QLEDs rely on heavy-metal-based quantum dots (QDs), which pose a significant barrier to their future commercialization. Herein we present the first LSPR-enhanced eco-friendly green ZnSeTe-based QLEDs by incorporating Au nanoparticles into the ZnMgO electron transport layer (ETL) and optimizing their concentration to maximize the LSPR effect. As a result, the optimal plasmonic devices exhibited a significant improvement in performance, with the maximum external quantum efficiency (EQE) substantially increased from 7.15% to 11.75% and the extrapolated T₅₀ lifetime at 1000 cd m^–2 markedly extended from 107.63 to 150.41 h. Consequently, this work provides an efficient strategy toward developing high-performance, eco-friendly green QLEDs.

Photocatalytic H₂O₂ production coupled with uranyl ion complexation to form UO₂(O₂) precipitates provides an energy-efficient solution for uranium recovery. However, the currently used photocatalysts often require sacrificial agents and lack stability. Herein, a porphyrin-based conjugated microporous polymer, Bpy-Por-CMP, was synthesized via a one-step method utilizing pyrrole- and aldehyde-based ligands. Bpy-Por-CMP exhibited a high uranium extraction rate of 95.4% under simulated sunlight without sacrificial agents, maintaining over 94.0% efficiency across a pH range of 3–9. In contrast with biphenyl ligands, bipyridine ligands were found to construct a donor–acceptor structure with the porphyrins. This unique structure enhances photoinduced charge separation, facilitating effective photocatalytic H₂O₂ production and uranium extraction. This work demonstrates the application of a bipyridyl porphyrin-based conjugated microporous polymer for uranium extraction via the UO₂(O₂)-based approach under non-sacrificial and ambient conditions. The chemical stability and high uranium extraction performance of this material highlight its practical application in nuclear wastewater treatment.

Capacitive Deionization (CDI) has become a viable and energy-efficient desalination process nowadays. Conventional electrodes for CDI application possessed low ion adsorption capability. Recent advancements focus on faradaic electrodes, which exploit redox reactions to produce improved ion storage through pseudocapacitive and intercalation effects. Advanced materials offer improved desalination efficiency, operating adaptability, and charge storage properties. Advanced CDI electrode efficiency improved due to faradaic ion storage, such as cathodic oxygen reduction and intercalation reactions which resulted through the development of electrode functionality and design. This review thoroughly examines recent developments in capacitive and faradaic materials-based electrodes for CDI, focusing on material synthesis and performance optimization. The review outlines limitations such as parameter optimization, electrode deterioration, and integration into scalable CDI systems. Emerging materials offer effective desalination efficacy by tackling these limitations. This review critically analyzes the drawbacks of traditional carbon-based CDI electrodes and their physiochemical advancements, and assesses their economic viability.

Many transition-metal-based catalysts, including metal–organic frameworks (MOFs), usually undergo reconstruction to form catalytically active oxyhydroxide sites during the oxygen evolution reaction (OER). However, structural transformation of conventional bulk MOFs mostly occurs at the surface, while internal active centers are not utilized, limiting the improvement in electrocatalytic performance. Herein, we demonstrate that reducing the MOF dimension can accelerate the transformation to metal oxyhydroxides and boost the OER activity. An ultralong NiCo-MOF-74 nanowire (NiCo-MOF-74-NW) enriched with surface open metal sites is prepared by a “pre-assembly–crystallization” strategy. Structural characterization and in situ analysis reveal that the nanowire morphology facilitates reconstruction into active CoOOH species during electrocatalysis. NiCo-MOF-74-NW achieves a low overpotential of 292 mV at 100 mA cm^–2, along with enhanced intrinsic activity and favorable reaction kinetics compared to MOF microrods (NiCo-MOF-74-MR). This work provides insights for designing MOF-based electrocatalysts through the decrease of dimensions to promote surface reconstruction.

Metal–organic frameworks (MOFs) represent a well-defined class of materials capable of incorporating catalytically active sites for gas-phase catalysis. However, the reducing conditions of hydrogenation catalysis can lead to nanoparticle formation in MOFs, which can significantly diminish the catalytic activity of single-site metals and reduce the longevity of MOF-based hydrogen solutions. Here, we present a straightforward approach to accessing catalytically active single metal sites in a robust Ni-MFU-4l MOF for gas-phase hydrogenation without the formation of Ni nanoparticles. By carefully tuning the local node chemistry through postsynthetic exchange of the terminal ligand coordinated to the Ni(II) centers in the MOF, from −Cl to −OH or −HCOO, we can readily generate Ni–H active species. We further demonstrate, using in situ pair-distribution function analysis, that these Ni–H sites are the sole catalytically active sites in the terminal ligand-exchanged counterparts, whereas nanoparticles readily form in the parent Ni-MFU-4l-Cl under otherwise identical catalytic conditions.

Group IV color centers in diamond are promising single-photon emitters for quantum information processing and networking. Among them, the tin-vacancy (SnV) center stands out due to its long spin coherence times at cryogenic temperatures above 1 K. While SnV centers have been realized using various fabrication routes, their in situ formation via microwave plasma-enhanced chemical vapor deposition (MW PE CVD) remains relatively unexplored. In this study, SnV centers, identified by a zero-phonon line (ZPL) near 620 nm, were synthesized in nanocrystalline diamond and free-standing microcrystalline diamond using tin oxide (SnO₂) as a dopant source at substrate temperatures of 750°C and 850°C. Photoluminescence measurements reveal that lowering the substrate temperature enhances both the ZPL intensity and spatial uniformity of SnV centers. These results highlight substrate temperature as a key parameter for controlling SnV incorporation during MW PE CVD growth and provide insights into optimizing fabrication strategies for diamond-based quantum technologies.

High overpotential resulting from the slow reaction rate of the oxygen reduction reaction (ORR) at air electrodes limits the practical use of proton exchange membrane fuel cells (PEMFCs) and zinc–air batteries (ZABs). In this study, a simplified single-step synthesis of PdAg alloy nanoparticles loaded on reduced graphene oxide (PdAg-rGO) as a bifunctional catalyst for the ORR and the oxygen evolution reaction (OER) was designed. Electrochemical evaluations revealed that the PdAg-rGO electrocatalyst showed a good ORR E_onset potential in alkaline (0.87 V) and acidic media (0.74 V). For the OER, PdAg-rGO required a 290 mV overpotential to deliver 50 mA cm^–2 and a Tafel slope of 61 mV dec^–1. Notably, PdAg-rGO demonstrated long durability, maintaining stable performance over 120 h in ZAB and over 100 h in PEMFC tests. The findings highlight the practical potential of the PdAg alloy as a robust and versatile ORR catalyst for emerging technologies in energy systems.

The generation and manipulation of photoinduced transient currents, as well as characterization of the emission of resultant electromagnetic waves, are crucial for the design and coherent operation of advanced optoelectronic devices. An ultrafast optical pulse-driven transient photocurrent lasts for picosecond time scale bursts as a terahertz (THz) emission. The emitted radiation, permitted by the intrinsic structural properties of materials, is remarkably enriched with information on associated ultrafast transients and can potentially explore microscopic insights into fascinating nonlinear dynamical characteristics. This review aims to understand terahertz (THz) emission and the underlying ultrafast photophysics in contemporary matter systems. Since THz emission is the manifestation of photocurrents and induced dynamic polarization that sustain a picosecond time scale, it offers a noncontact and noninvasive platform for studying such ultrafast phenomena.

Postoperative recurrence and metastasis remain major causes of mortality in breast cancer due to residual tumor cells and complex metastatic processes. Here, we develop an NIR-responsive MXene-based scaffold that integrates antiplatelet therapy, chemotherapy, and photothermal therapy for postoperative intervention. The scaffold is fabricated by printing sodium alginate, gelatin methacryloyl, and MXene into CaCl₂ solution followed by UV cross-linking. Benefiting from the photothermal capacity of MXene nanosheets, the scaffold enables efficient photothermal conversion and NIR-triggered drug release. Incorporation of the platelet glycoprotein (GPVI) inhibitor evobrutinib disrupts platelet–tumor interactions, thereby suppressing epithelial–mesenchymal transition and tumor invasion. In vivo, the scaffold provides sustained doxorubicin release and photothermal ablation to inhibit residual tumor growth while reducing lung metastasis through GPVI blockade. Transcriptomic analysis further confirms that the scaffold impedes tumor progression by modulating platelet activation and angiogenesis. This multifunctional platform offers a promising strategy for preventing postoperative breast cancer recurrence and metastasis.