RESUMO
Ordered layered structures serve as essential components in lithium (Li)-ion cathodes1-3. However, on charging, the inherently delicate Li-deficient frameworks become vulnerable to lattice strain and structural and/or chemo-mechanical degradation, resulting in rapid capacity deterioration and thus short battery life2,4. Here we report an approach that addresses these issues using the integration of chemical short-range disorder (CSRD) into oxide cathodes, which involves the localized distribution of elements in a crystalline lattice over spatial dimensions, spanning a few nearest-neighbour spacings. This is guided by fundamental principles of structural chemistry and achieved through an improved ceramic synthesis process. To demonstrate its viability, we showcase how the introduction of CSRD substantially affects the crystal structure of layered Li cobalt oxide cathodes. This is manifested in the transition metal environment and its interactions with oxygen, effectively preventing detrimental sliding of crystal slabs and structural deterioration during Li removal. Meanwhile, it affects the electronic structure, leading to improved electronic conductivity. These attributes are highly beneficial for Li-ion storage capabilities, markedly improving cycle life and rate capability. Moreover, we find that CSRD can be introduced in additional layered oxide materials through improved chemical co-doping, further illustrating its potential to enhance structural and electrochemical stability. These findings open up new avenues for the design of oxide cathodes, offering insights into the effects of CSRD on the crystal and electronic structure of advanced functional materials.
RESUMO
Within the family of two-dimensional dielectrics, rhombohedral boron nitride (rBN) is considerably promising owing to having not only the superior properties of hexagonal boron nitride1-4-including low permittivity and dissipation, strong electrical insulation, good chemical stability, high thermal conductivity and atomic flatness without dangling bonds-but also useful optical nonlinearity and interfacial ferroelectricity originating from the broken in-plane and out-of-plane centrosymmetry5-23. However, the preparation of large-sized single-crystal rBN layers remains a challenge24-26, owing to the requisite unprecedented growth controls to coordinate the lattice orientation of each layer and the sliding vector of every interface. Here we report a facile methodology using bevel-edge epitaxy to prepare centimetre-sized single-crystal rBN layers with exact interlayer ABC stacking on a vicinal nickel surface. We realized successful accurate fabrication over a single-crystal nickel substrate with bunched step edges of the terrace facet (100) at the bevel facet (110), which simultaneously guided the consistent boron-nitrogen bond orientation in each BN layer and the rhombohedral stacking of BN layers via nucleation near each bevel facet. The pure rhombohedral phase of the as-grown BN layers was verified, and consequently showed robust, homogeneous and switchable ferroelectricity with a high Curie temperature. Our work provides an effective route for accurate stacking-controlled growth of single-crystal two-dimensional layers and presents a foundation for applicable multifunctional devices based on stacked two-dimensional materials.
RESUMO
Ferroelectricity, especially the Si-compatible type recently observed in hafnia-based materials, is technologically useful for modern memory and logic applications, but it is challenging to differentiate intrinsic ferroelectric polarization from the polar phase and oxygen vacancy. Here, we report electrically controllable ferroelectricity in a Hf0.5Zr0.5O2-based heterostructure with Sr-doped LaMnO3, a mixed ionic-electronic conductor, as an electrode. Electrically reversible extraction and insertion of an oxygen vacancy into Hf0.5Zr0.5O2 are macroscopically characterized and atomically imaged in situ. Utilizing this reversible process, we achieved multilevel polarization states modulated by the electric field. Our study demonstrates the usefulness of the mixed conductor to repair, create, manipulate, and utilize advanced ferroelectric functionality. Furthermore, the programmed ferroelectric heterostructures with Si-compatible doped hafnia are desirable for the development of future ferroelectric electronics.
RESUMO
OBJECTIVE: The objective is to develop a natural and stable anti-oxidative stress and anti-ageing ingredient. In this study, we evaluated the changes in white tea leaves fermented with Eurotium cristatum PLT-PE and Saccharomyces boulardii PLT-HZ and their efficacy against skin oxidative stress. METHODS: We employed untargeted metabolomics technology to analyse the differential metabolites between tea extract (TE) and fermented tea extract (FTE). In vitro, using H2O2-induced HaCaT cells, we evaluated cell vitality, ROS, and inflammatory factors (TNF-α, IL-1ß, and IL-6). Additionally, we verified the effects on the extracellular matrix and nuclear DNA using fibroblasts or reconstructed skin models. We measured skin hydration, elasticity, wrinkle area, wrinkle area ratio, erythema area, and erythema area ratio in volunteers after using an emulsion containing 3% FTE for 28 and 56 days. RESULTS: Targeted metabolomics analysis of white tea leaves yielded more than 20 differential metabolites with antioxidant and anti-inflammatory activities, including amino acids, polypeptides, quercetin, and liquiritin post-fermentation. FTE, compared to TE, can significantly reduce reactive oxygen species (ROS) and protect against oxidative stress-induced skin damage in H2O2-induced HaCaT cells. FTE can inhibit H2O2-induced collagen degradation by suppressing the MAPK/c-Jun signalling pathway and can also mitigate the reactive oxygen species damage to nuclear DNA. Clinical studies showed that the volunteers' stratum corneum water content, skin elasticity, wrinkle area, wrinkle area ratio, erythema area, and erythema area ratio significantly improved from the baseline after 28 and 56 days of FTE use. CONCLUSION: This study contributes to the growing body of literature supporting the protective effects against skin oxidative stress and ageing from fermented plant extracts. Moreover, our findings might inspire multidisciplinary efforts to investigate new fermentation techniques that could produce even more potent anti-ageing solutions.
OBJECTIF: L'objectif est de développer un ingrédient naturel et stable contre le stress oxydatif et antiâge. Dans cette étude, nous avons évalué les modifications dans les feuilles de thé blanc fermentées avec la PLTPE Eurotium cristatum et la PLTHZ Saccharomyces boulardii et leur efficacité contre le stress oxydatif cutané. MÉTHODES: Nous avons utilisé une technologie de métabolomique non ciblée pour analyser les métabolites différentiels entre l'extrait de thé (ET) et l'extrait de thé fermenté (ETF). In vitro, à l'aide de cellules HaCaT induites par l'H2O2, nous avons évalué la vitalité cellulaire, les ERO et les facteurs inflammatoires (TNFα, IL1ß, and IL6). Nous avons également vérifié les effets sur la matrice extracellulaire et l'ADN nucléaire à l'aide de fibroblastes ou de modèles cutanés reconstruits. Nous avons mesuré l'hydratation de la peau, l'élasticité, la surface de rides, le rapport des surfaces de rides, la surface d'érythème, et le rapport des surfaces d'érythème chez des volontaires ayant utilisé une émulsion contenant 3% d'ETF pendant 28 et 56 jours. RÉSULTATS: L'analyse métabolomique ciblée des feuilles de thé blanc a révélé plus de 20 métabolites différentiels ayant des activités antioxydantes et antiinflammatoires, notamment des acides aminés, des polypeptides, de la quercétine et de la liquiritine après fermentation. Par rapport à l'ET, l'ETF peut réduire significativement les espèces réactives de l'oxygène (ERO) et protéger contre les lésions cutanées induites par le stress oxydatif dans les cellules HaCaT induites par l'H2O2. L'ETF peut inhiber la dégradation du collagène induite par l'H2O2 en supprimant la voie de signalization MAPK/cJun et peut également atténuer les dommages causés par les espèces réactives de l'oxygène à l'ADN nucléaire. Les études cliniques ont montré que la teneur en eau de la couche cornée des volontaires, l'élasticité de la peau, la surface de rides, le rapport des surfaces de rides, la surface d'érythème et le rapport des surfaces d'érythème se sont significativement améliorés par rapport à la référence après 28 et 56 jours d'utilisation d'ETF. CONCLUSION: Cette étude contribue au corpus croissant de littérature soutenant les effets protecteurs des extraits de plantes fermentées contre le stress oxydatif cutané et le vieillissement. En outre, nos résultats pourraient inspirer des efforts pluridisciplinaires pour étudier de nouvelles techniques de fermentation susceptibles de produire des solutions antiâge encore plus puissantes.
RESUMO
One of the primary challenges to improving lithium-ion batteries lies in comprehending and controlling the intricate interphases. However, the complexity of interface reactions and the buried nature make it difficult to establish the relationship between the interphase characteristics and electrolyte chemistry. Herein, we employ diverse characterization techniques to investigate the progression of electrode-electrolyte interphases, bringing forward opportunities to improve the interphase properties by what we refer to as high-entropy solvation disordered electrolytes. Through formulating an electrolyte with a regular 1.0 M concentration that includes multiple commercial lithium salts, the solvation interaction with lithium ions alters fundamentally. The participation of several salts can result in a weaker solvation interaction, giving rise to an anion-rich and disordered solvation sheath despite the low salt concentration. This induces a conformal, inorganic-rich interphase that effectively passivates electrodes, preventing solvent co-intercalation. Remarkably, this electrolyte significantly enhances the performance of graphite-containing anodes paired with high-capacity cathodes, offering a promising avenue for tailoring interphase chemistries.
RESUMO
This research examines the anti-aging potential of the flavonoid derivative of isoquercitrin known as enzymatically modified isoquercitrin (EMIQ). Initial HPLC analyses showed that EMIQ used in the study contained 1-12 glucosides and 10.7% pentahydroxyflavonoids, promising potent antioxidant properties. In subsequent in-vitro studies with UVA-exposed human dermal fibroblasts (HDFa), EMIQ demonstrated protective properties by reducing collagen damage. It modulated both the TGFß/Smad pathway and the MMP1 pathway, contributing to collagen preservation. This protective effect was further confirmed using the T-Skin™ model, a reconstructed full-thickness human skin model, which illustrated that EMIQ could defend the physiological structures of both the epidermis and dermis against UV radiation. A 28-day clinical trial with 30 volunteers aged 31-55 years highlighted EMIQ's effectiveness. Participants using EMIQ-containing Essence displayed reduced facial trans-epidermal water loss and skin roughness, alongside improved skin elasticity. This study emphasizes EMIQ's potential as an anti-photoaging ingredient in cosmetics, warranting further research. The findings pave the way for developing innovative skincare products addressing photoaging effects.
RESUMO
Mastering the self-organization of nanoparticle morphologies is pivotal in soft matter physics and film growth. Silicon dioxide (SiO2) nanoparticles are an archetypical model of nanomotor in soft matter. Here, the emphasis is on the self-organizing behavior of SiO2 nanoparticles under extreme conditions. It is unveiled that manipulating the states of the metal substrate profoundly dictates the motion characteristics of SiO2 nanoparticles. This manipulation triggers the emergence of intricate morphologies and distinctive patterns. Employing a reaction-diffusion model, the fundamental roles played by Brownian motion and Marangoni-driven motion in shaping fractal structures and radial Turing patterns are demonstrated, respectively. Notably, these radial Turing patterns showcase hyperuniform order, challenging conventional notions of film morphology. These discoveries pave the way for crafting non-equilibrium morphological materials, poised with the potential for self-healing, adaptability, and innovative applications.
RESUMO
OBJECTIVES: To investigate and compare the chemical and optical stability of four restorative composite materials: two injectable resins, one flowable resin and one compomer. METHODS: Two injectable nano-filled composite resins: G-aenial Universal (GU) and Beautifil Injectable XSL (BI), a flowable composite resin: Filtek Supreme Flowable (FS) and a compomer: Dyract Flow (DF), in A2 shade were tested and compared. Water sorption and solubility were conducted according to ISO4049:2019 standard; ICP-OES and F-ion selective electrode were used to test the elemental release; Degree of conversion (DC) was obtained by using FTIR; water contact angle was obtained by static sessile drop method, and a spectrophotometer was used for optical properties (ΔEâ, ΔLâ and TP). SPSS 28.0 was used for statistical analysis and the significant level was pre-set as α = 0.05. RESULTS: GU performed the best in water sorption and solubility, FS had the lowest elemental release, the best colour stability, and the highest DCIM and DC24-h. DF, the compomer had the lowest, and GU and BI, the injectable composites had the largest water contact angle, respectively. Correlations were found between water sorption and water solubility. CONCLUSIONS: The four composite restorative materials showed different chemical and optical behaviours. Overall, composite resins performed better than compomer, while additional laboratory and in vivo tests are necessary to obtain a more comprehensive comparison between injectable and flowable composite resins. Wsp and Wsl are influenced by many common factors, and the values are highly positively related. CLINICAL SIGNIFICANCE: A comprehensive understanding of materials is crucial before selecting materials for clinical practice. Composite resins rather than compomers are recommended because of their exceptional properties, which make them eligible for a wide range of clinical applications and an elongated lifespan.
Assuntos
Cor , Compômeros , Resinas Compostas , Materiais Dentários , Teste de Materiais , Solubilidade , Água , Resinas Compostas/química , Materiais Dentários/química , Água/química , Compômeros/química , Humanos , Restauração Dentária Permanente/métodos , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier , Metacrilatos/química , Injeções , Poliuretanos/química , Nanocompostos/química , Propriedades de Superfície , Fenômenos Ópticos , Bis-Fenol A-Glicidil MetacrilatoRESUMO
OBJECTIVE: As osteoporosis progresses, the primary compressive trabeculae (PCT) in the proximal femur remains preserved and is deemed the principal load-bearing structure that links the femoral head with the femoral neck. This study aims to elucidate the distribution patterns of PCT within the proximal femur in the elderly population, and to assess its implications for the development and optimization of internal fixation devices used in hip fracture surgeries. METHODS: This is a retrospective cohort study conducted from March 2022 to April 2023. A total of 125 patients who underwent bilateral hip joint CT scans in our hospital were enrolled. CT data of the unaffected side of the hip were analyzed. Key parameters regarding the PCT distribution in the proximal femur were measured, including the femoral head's radius (R), the neck-shaft angle (NSA), the angle between the PCT-axis and the head-neck axis (α), the distance from the femoral head center to the PCT-axis (δ), and the lengths of the PCT's bottom and top boundaries (L-bottom and L-top respectively). The impact of gender differences on PCT distribution patterns was also investigated. Student's t-test or Mann-Whitney U test were used to compare continuous variables between genders. The relationship between various variables was investigated through Pearson's correlation analysis. RESULTS: PCT was the most prominent bone structure within the femoral head. The average NSA, α, and δ were 126.85 ± 5.85°, 37.33 ± 4.23°, and 0.39 ± 1.22 mm, respectively, showing no significant gender differences (p > 0.05). Pearson's correlation analysis revealed strong correlations between α and NSA (r = -0.689, p < 0.001), and R and L-top (r = 0.623, p < 0.001), with mild correlations observed between δ and NSA (r = -0.487, p < 0.001), and R and L-bottom (r = 0.427, p < 0.001). Importantly, our study establishes a method to accurately localize PCT distribution in true anteroposterior (AP) radiographs of the hip joint, facilitating precise screw placement in proximal femur fixation procedures. CONCLUSION: Our study provided unprecedented insights into the distribution patterns of PCT in the proximal femur of the elderly population. The distribution of PCT in the proximal femur is predominantly influenced by anatomical and geometric factors, such as NSA and femoral head size, rather than demographic factors like gender. These insights have crucial implications for the design of internal fixation devices and surgical planning, offering objective guidance for the placement of screws in hip fracture treatments.
Assuntos
Tomografia Computadorizada por Raios X , Humanos , Feminino , Masculino , Estudos Retrospectivos , Idoso , Idoso de 80 Anos ou mais , Fêmur/diagnóstico por imagem , Cabeça do Fêmur/diagnóstico por imagem , Osso Esponjoso/diagnóstico por imagem , Pessoa de Meia-Idade , Colo do Fêmur/diagnóstico por imagemRESUMO
The vast compositional space available in high-entropy oxide semiconductors offers unique opportunities for electronic band structure engineering in an unprecedented large room. In this work, with wide band gap semiconductor lithium niobate (LiNbO3) as a model system, we show that the substitutional addition of high-entropy metal cation mixtures within the Nb sublattice can lead to the formation of a single-phase solid solution featuring a substantially narrowed band gap and intense broadband visible light absorption. The resulting high-entropy LiNbO3 [denoted as Li(HE)O3] crystallizes as well-faceted nanocubes; atomic-resolution imaging and elemental mapping via transmission electron microscopy unveil a distinct local chemical complexity and lattice distortion, characteristics of high-entropy stabilized solid solution phases. Because of the presence of high-entropy stabilized Co2+ dopants that serve as active catalytic sites, Li(HE)O3 nanocubes can accomplish the visible light-driven photocatalytic water splitting in an aqueous solution containing methanol as a sacrificial electron donor without the need of any additional co-catalysts.
RESUMO
OBJECTIVES: To evaluate the mechanical, wear, antibacterial properties, and biocompatibility of injectable composite materials. METHODS: Two injectable composite resins (GU and BI), one flowable composite resin (FS), and one flowable compomer (DF), in A2 shade, were tested. Mechanical properties were tested via three-point bending test immediately after preparation and after 1-day, 7-day, 14-day, and 30-day water storage. Under water-PMMA slurry immersion, specimens were subjected to a 3-body wear test (10,000 cycles) against stainless steel balls, while the roughness, wear depth, and volume loss were recorded. After 1-day and 3-day MC3T3-E1 cell culture, cell viability was evaluated with CCK-8 test kits, while the cell morphology was observed under CLSM and SEM. Antibacterial properties on S. mutans were assessed via CFU counting, CLSM, and SEM observation. SPSS 26.0 was used for statistical analysis (α = 0.05). RESULTS: The mechanical properties were material-dependent and sensitive to water storage. Flexural strength ranked GU > FS > BI > DF at all testing levels. Three nanocomposites had better wear properties than DF. No significant difference on 1-day cell viability was found, but DF showed significantly lower cell proliferation than nanocomposites on 3-day assessment. GU and FS had more favourable cell adhesion and morphology. CFU counting revealed no significant difference, while FS presented a slightly thicker biofilm and BI showed relatively lower bacteria density. CONCLUSIONS: Injectable nanocomposites outperformed the compomer regarding mechanical properties, wear resistance, and biocompatibility. The tested materials presented comparable antibacterial behaviours. Flowable resin-based composites' performances are affected by multiple factors, and their compositions can be attributed. CLINICAL SIGNIFICANCE: A profound understanding of the mechanical, wear, and biological properties of the restorative material is imperative for the clinical success of dental restorations. The current study demonstrated superior properties of highly filled injectable composite resins, which imply their wider indications and better long-term clinical performances.
Assuntos
Antibacterianos , Materiais Biocompatíveis , Sobrevivência Celular , Resinas Compostas , Teste de Materiais , Streptococcus mutans , Propriedades de Superfície , Resinas Compostas/química , Resinas Compostas/farmacologia , Antibacterianos/farmacologia , Streptococcus mutans/efeitos dos fármacos , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Camundongos , Animais , Sobrevivência Celular/efeitos dos fármacos , Materiais Dentários/química , Compômeros/farmacologia , Água/química , Nanocompostos/química , Resistência à Flexão , Injeções , Polimetil Metacrilato/químicaRESUMO
Cu-oxide-based catalysts are promising for CO2 electroreduction (CO2RR) to CH4, but suffer from inevitable reduction (to metallic Cu) and uncontrollable structural collapse. Here we report Cu-based rock-salt-ordered double perovskite oxides with superexchange-stabilized long-distance Cu sites for efficient and stable CO2-to-CH4 conversion. For the proof-of-concept catalyst of Sr2CuWO6, its corner-linked CuO6 and WO6 octahedral motifs alternate in all three crystallographic dimensions, creating sufficiently long Cu-Cu distances (at least 5.4 Å) and introducing marked superexchange interaction mainly manifested by O-anion-mediated electron transfer (from Cu to W sites). In CO2RR, the Sr2CuWO6 exhibits significant improvements (up to 14.1 folds) in activity and selectivity for CH4, together with well boosted stability, relative to a physical-mixture counterpart of CuO/WO3. Moreover, the Sr2CuWO6 is the most effective Cu-based-perovskite catalyst for CO2 methanation, achieving a remarkable selectivity of 73.1% at 400 mA cm-2 for CH4. Our experiments and theoretical calculations highlight the long Cu-Cu distances promoting *CO hydrogenation and the superexchange interaction stabilizing Cu sites as responsible for the superb performance.
RESUMO
Layered O3-type oxides are one of the most promising cathode materials for Na-ion batteries owing to their high capacity and straightforward synthesis. However, these materials often experience irreversible structure transitions at elevated cutoff voltages, resulting in compromised cycling stability and rate performance. To address such issues, understanding the interplay of the composition, structure, and properties is crucial. Here, we successfully introduced a P-type characteristic into the O3-type layered structure, achieving a P3-dominated solid-solution phase transition upon cycling. This modification facilitated a reversible transformation of the O3-P3-P3' structure with minimal and gradual volume changes. Consequently, the Na0.75Ni0.25Cu0.10Fe0.05Mn0.15Ti0.45O2 cathode exhibited a specific capacity of approximately 113 mAh/g, coupled with exceptional cycling performance (maintaining over 70% capacity retention after 900 cycles). These findings shed light on the composition-structure-property relationships of Na-ion layered oxides, offering valuable insights for the advancement of Na-ion batteries.
RESUMO
All-solid-state lithium batteries have attracted widespread attention for next-generation energy storage, potentially providing enhanced safety and cycling stability. The performance of such batteries relies on solid electrolyte materials; hence many structures/phases are being investigated with increasing compositional complexity. Among the various solid electrolytes, lithium halides show promising ionic conductivity and cathode compatibility, however, there are no effective guidelines when moving toward complex compositions that go beyond ab-initio modeling. Here, we show that ionic potential, the ratio of charge number and ion radius, can effectively capture the key interactions within halide materials, making it possible to guide the design of the representative crystal structures. This is demonstrated by the preparation of a family of complex layered halides that combine an enhanced conductivity with a favorable isometric morphology, induced by the high configurational entropy. This work provides insights into the characteristics of complex halide phases and presents a methodology for designing solid materials.
RESUMO
Multiferroic materials, which simultaneously exhibit ferroelectricity and magnetism, have attracted substantial attention due to their fascinating physical properties and potential technological applications. With the trends towards device miniaturization, there is an increasing demand for the persistence of multiferroicity in single-layer materials at elevated temperatures. Here, we report high-temperature multiferroicity in single-layer CuCrSe2, which hosts room-temperature ferroelectricity and 120 K ferromagnetism. Notably, the ferromagnetic coupling in single-layer CuCrSe2 is enhanced by the ferroelectricity-induced orbital shift of Cr atoms, which is distinct from both types I and II multiferroicity. These findings are supported by a combination of second-harmonic generation, piezo-response force microscopy, scanning transmission electron microscopy, magnetic, and Hall measurements. Our research provides not only an exemplary platform for delving into intrinsic magnetoelectric interactions at the single-layer limit but also sheds light on potential development of electronic and spintronic devices utilizing two-dimensional multiferroics.
RESUMO
Nanomaterials with a large chiroptical response and high structural stability are desirable for advanced miniaturized optical and optoelectronic applications. One-dimensional (1D) nanotubes are robust crystals with inherent and continuously tunable chiral geometries. However, their chiroptical response is typically weak and hard to control, due to the diverse structures of the coaxial tubes. Here we demonstrate that as-grown multiwalled boron nitride nanotubes (BNNTs), featuring coherent-stacking structures including near monochirality, homo-handedness and unipolarity among the component tubes, exhibit a scalable nonlinear chiroptical response. This intrinsic architecture produces a strong nonlinear optical response in individual multiwalled BNNTs, enabling second-harmonic generation (SHG) with a conversion efficiency up to 0.01% and output power at the microwatt level-both excellent figures of merit in the 1D nanomaterials family. We further show that the rich chirality of the nanotubes introduces a controllable nonlinear geometric phase, producing a chirality-dependent SHG circular dichroism with values of -0.7 to +0.7. We envision that our 1D chiral platform will enable novel functions in compact nonlinear light sources and modulators.
RESUMO
Monolayer molybdenum disulfide (MoS2), an emergent two-dimensional (2D) semiconductor, holds great promise for transcending the fundamental limits of silicon electronics and continue the downscaling of field-effect transistors. To realize its full potential and high-end applications, controlled synthesis of wafer-scale monolayer MoS2 single crystals on general commercial substrates is highly desired yet challenging. Here, we demonstrate the successful epitaxial growth of 2-inch single-crystal MoS2 monolayers on industry-compatible substrates of c-plane sapphire by engineering the formation of a specific interfacial reconstructed layer through the S/MoO3 precursor ratio control. The unidirectional alignment and seamless stitching of MoS2 domains across the entire wafer are demonstrated through cross-dimensional characterizations ranging from atomic- to centimeter-scale. The epitaxial monolayer MoS2 single crystal shows good wafer-scale uniformity and state-of-the-art quality, as evidenced from the ~100% phonon circular dichroism, exciton valley polarization of ~70%, room-temperature mobility of ~140 cm2v-1s-1, and on/off ratio of ~109. Our work provides a simple strategy to produce wafer-scale single-crystal 2D semiconductors on commercial insulator substrates, paving the way towards the further extension of Moore's law and industrial applications of 2D electronic circuits.