Temporal and spatial evolution simulation and attribution analysis of vegetation photosynthesis over the past 21 years based on satellite SIF data: a case study from Asia.

Photosynthesis in vegetation is one of the key processes in maintaining regional ecological balance and climate stability, and it is of significant importance for understanding the health of regional ecosystems and addressing climate change. Based on 2001-2021 Global OCO-2 Solar-Induced Fluorescence (GOSIF) dataset, this study analyzed spatiotemporal variations in Asian vegetation photosynthesis and its response to climate and human activities. Results show the following: (1) From 2001 to 2021, the overall photosynthetic activity of vegetation in the Asian region has shown an upward trend, exhibiting a stable distribution pattern with higher values in the eastern and southern regions and lower values in the central, western, and northern regions. In specific regions such as the Turgen Plateau in northwestern Kazakhstan, Cambodia, Laos, and northeastern Syria, photosynthesis significantly declined. (2) Meteorological factors influencing photosynthesis exhibit differences based on latitude and vertical zones. In low-latitude regions, temperature is the primary driver, while in mid-latitude areas, solar radiation and precipitation are crucial. High-latitude regions are primarily influenced by temperature, and high-altitude areas depend on precipitation and solar radiation. (3) Human activities (56.44%) have a slightly greater impact on the dynamics of Asian vegetation photosynthesis compared to climate change (43.56%). This research deepens our comprehension of the mechanisms behind the fluctuations in Asian vegetation photosynthesis, offering valuable perspectives for initiatives in environmental conservation, sustainability, and climate research.

Multiple strategies of improving photocatalytic water splitting efficiency in 2D arsenic sesquichalcogenides.

Improving the solar-to-hydrogen efficiency has always been a significant topic in the field of photocatalysis. Based on first-principles calculations, herein, we propose multiple strategies to improve the photocatalytic properties of 2D arsenic sesquichalcogenides for full water splitting. The new configurations As2STe2 and As2SeTe2 monolayers, derived from the As2Te3 monolayers by surface modification, are manifested to be typical infrared-light driven photocatalysts. Notably, under the built-in electric field, As2STe2 and As2SeTe2 monolayers can fulfil overall water splitting and the predicted solar-to-hydrogen efficiencies even reach up to 36.19% and 29.36%, respectively. The Gibbs free energy calculations indicate that the OER can be successfully driven under light irradiation. In addition, the overpotentials can provide most of the energy for HER when illuminated, especially for As2STe2 with the . In addition, both As2S3 and As2Se3 monolayers are capable of satisfying the conditions for photocatalytic water splitting. Furthermore, the band gaps of As2Se3 and As2S3 can dramatically be narrowed by increasing the number of layers and doping, respectively. These findings provide a theoretical basis for As2X3 monolayers to achieve efficient photocatalytic water splitting.

Effects of Inorganic Substitutions and Different Metal Electrode Materials on Electronic Transport Properties of Organic Molecular Devices.

Incorporating inorganic components into organic molecular devices offers one novel alternative to address challenges existing in the fabrication and integration of nanoscale devices. In this study, using a theoretical method of density functional theory combined with the nonequilibrium Green's function, a series of benzene-based molecules with group III and V substitutions, including borazine molecule and XnB3-nN3H6 (X = Al or Ga, n = 1-3) molecules/clusters, are constructed and investigated. An analysis of electronic structures reveals that the introduction of inorganic components effectively reduces the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, albeit at the cost of reduced aromaticity in these molecules/clusters. Simulated electronic transport characteristics demonstrate that XnB3-nN3H6 molecules/clusters coupled between metal electrodes exhibit lower conductance compared to prototypical benzene molecule. Additionally, the choice of metal electrode materials significantly impacts the electronic transport properties, with platinum electrode devices displaying distinct behavior compared to silver, copper, and gold electrode devices. This distinction arises from the amount of transferred charge, which modulates the alignment between molecular orbitals and the Fermi level of the metal electrodes by shifting the molecular orbitals in energy. These findings provide valuable theoretical insights for the future design of molecular devices incorporating inorganic substitutions.

Dual transmission channels at metal-MoS2/WSe2 hetero-bilayer interfaces.

van der Waals heterostructures (vdWHs) open the possibility of creating novel semiconductor materials at the atomic scale that demonstrate totally new physics and enable unique functionalities, and have therefore attracted great interest in the fields of advanced electronic and optoelectronic devices. However, the interactions between metals and vdWHs semiconductors require further investigation as they directly affect or limit the advancement of high-performance electronic devices. Here we study the contact behavior of MoS2/WSe2 vdWHs in contact with a series of bulk metals using ab initio electronic structure calculations and quantum transport simulations. Our study shows that dual transmission paths for electrons and holes exist at the metal-MoS2/WSe2 hetero-bilayer interfaces. In addition, the metal-induced bandgap state (MIGS) of the original monolayer disappears due to the creation of the heterolayer, which weakens the Fermi level pinning (FLP) effect. We also find that the creation of the heterolayer causes a change in the Schottky barrier height (SBH) of the non-ohmic contact systems, whilst this does not occur so easily in the ohmic contact systems. In addition, our results indicate that when Al, Ag and Au are in contact with a MoS2/WSe2 hetero-bilayer semiconductor, a low contact barrier exists throughout the whole transmission process causing the charge to tunnel to the MoS2 layer, irrespective of whether the MoS2 is in contact with the metals as the nearest layer or as the next-nearest layer. Our work not only offers new insights into electrical contact issues between metals and hetero-bilayer semiconductors, but also provides guidance for the design of high-performance vdWHs semiconductor devices.

The co-pyrolysis of waste urea-formaldehyde resin with pine sawdust: co-pyrolysis behavior, pyrocarbon and its adsorption performance for Cr (VI).

Urea-formaldehyde (UF) resin is difficult to degrade and classified as hazardous organic waste. To address this concern, the co-pyrolysis behavior of UF resin with pine sawdust (PS) was studied, and the adsorption properties of pyrocarbon were evaluated with Cr (VI). Thermogravimetric analysis revealed that adding a small amount of PS can improve the pyrolysis behavior of UF resin. Based on the Flynn Wall Ozawa (FWO) method, the kinetics and activation energy values were estimated. It was observed that when the amount of UF resin exceeded twice that of PS, the activation energy of the reaction decreased, and they acted synergistically. The characterization of pyrocarbon samples showed that the specific surface area increased with the increase of temperature, while the content of functional groups showed the opposite trend. Intermittent adsorption experiments showed that 5UF + PS400 achieved 95% removal of 50 mg/L Cr (VI) at 0.6 g/L dosage and at pH 2. The adsorption process was consistent with the Langmuir isotherm and pseudo-second-order kinetics, and the maximum adsorption was 143.66 mg/g at 30 ℃. Furthermore, the adsorption process consisted of electrostatic adsorption, chelation, and redox reaction. Overall, this study provides a useful reference for the co-pyrolysis of UF resin and the adsorption capacity of pyrocarbon.

Influence and mechanism of alkali-modified sludge on coal water slurry properties.

Municipal sludge (MS) is used to prepare coal water slurry (CWS). This practice is beneficial for resource utilization and reduces treatment costs and environmental pollution. In this study, alkali-modified municipal sludge (AMS) was prepared with Ca(OH)2 as modifier and mixed with coal to produce AMS-CWS. The effect and mechanism of MS and AMS on slurry ability, stability, and combustion characteristics of the CWS were explored. The results of the pulping experiments showed that the slurry concentration of the AMS-CWS was approximately 10% greater than that of MS-CWS. The water separation rates of MS-CWS and AMS-CWS were 5% and 5.26%, respectively, which were 13.62% and 13.36% less than that of CWS (18.62%). The zeta potential experiments verified these results. Combustion performance research shows that both MS and AMS have positive effects on combustion performance. The results of the contact angle experiments showed that the hydrophobicity of AMS was enhanced, which was beneficial for improving the pulping capacity of MS-CWS.

Tunable Dirac states in doped B2S3 monolayers.

Two-dimensional (2D) Dirac materials have been a research hotspot due to their intriguing properties, such as high carrier mobility and ballistic charge transport. Here, we demonstrate that the B2S3 monolayer with a hexagonal structure, which has been reported as a photocatalyst, can be tuned to new 2D Dirac materials by doping atoms. The Young's modulus can reach 65.23 N m-1, indicating that the monolayer can be used as a buffer materials. The electronic structures of the pristine B2S3 monolayer show that some Dirac points appear but do not occur exactly on the Fermi level (EF). Fortunately, we find that the Dirac cone can be tuned to the EF by doping C, N, or Sn atoms. The C-doped B2S3 monolayer can be a half-metallic Dirac material, which has significant potential application in spintronics. For N- and Sn-doped B2S3 monolayers, the typical kagome bands are formed near the EF, which arise from three molecular orbitals hybridized by B, S, and N (Sn) atoms. These outstanding properties render the doped B2S3 monolayers promising 2D Dirac materials for future nanoelectronic devices.

Effect of bio-based surfactant on wettability of low-rank coal surface and its mechanism.

In this study, the effect of a bio-based environment-friendly surfactant, cardanol polyoxyethylene ether (BGF), on the wettability of the surface of low-rank coal (LRC) and its mechanism were studied. The adsorption experiment showed that the adsorption of the surfactant conformed to the Langmuir adsorption model and the pseudo-second-order kinetic model. The adsorption was mainly affected by hydrogen bonding, and the adsorption rate was affected by intraparticle diffusion and liquid film diffusion. The wettability experiment showed that the influence of BGF on the wettability of the surface of LRC followed the given order: BGF-7 > BGF-10 > BGF-15. The investigation of adhesion work showed that the adhesion work and the stability of the coal-water system decreased after adsorption. Fourier transform infrared and X-ray photoelectron spectroscopy analyses showed that after adsorption, the peak strength of vinyl ether, the content of elemental carbon, and the content of C-C/C-H groups increased.

Construction of Highly Proton-Conductive Zr(IV)-Based Metal-Organic Frameworks From Pyrrolo-pyrrole-Based Linkers with a Rhombic Shape.

To date, numerous zirconium cluster-based metal-organic frameworks (Zr-MOFs) with attractive physical properties have been achieved thanks to tailorable organic linkers and versatile Zr clusters. Nevertheless, in comparison with the most-used high-symmetry organic linkers, low-symmetry linkers have rarely been exploited in the construction of Zr-MOFs. Despite challenges in predicting the structure and topology of the MOF, linker desymmetrization presents opportunities for the design of Zr-MOFs with unusual topologies and unexpected functionalities. Herein, we report for the first time the construction of two robust Zr-MOFs (IAM-7 and IAM-8) from two pyrrolo-pyrrole-based low-symmetry tetracarboxylate linkers with a rare rhombic shape. The low symmetry of the linkers arises from the asymmetric pyrrolo-pyrrole core and the varying branch lengths, which play a critical role in the structural diversity between IAM-7 and IAM-8 seen from the structural analysis and lead to hydrophilic channels that contain uncoordinated carboxylate groups in the structure of IAM-7. Furthermore, the proton conductivity of IAM-7 displays a high temperature and humidity dependence where the proton conductivity increases from 2.84 × 10-8 S cm-1 at 30 °C and 40% relative humidity (RH) to 1.42 × 10-2 S cm-1 at 90 °C and 95% RH, making it among one of the most conductive Zr-MOFs. This work not only enriches the library of Zr-MOFs but also offers a platform for the design of low-symmetry linkers toward the structural diversity or irregularity of MOFs as well as their structure-related properties.

Novel 2D B2S3as a metal-free photocatalyst for water splitting.

Metal-free semiconductors with desirable characteristics have recently gained great attention in the field of hydrogen generation. The non-metal material B2S3has two phases, hexagonal B2S3(h-B2S3) and orthorhombic B2S3(o-B2S3), which compose a novel class of 2D materials. Bothh-B2S3ando-B2S3monolayers are direct semiconductors with bandgaps of 2.89 and 3.77 eV by the Heyd-Scuserria-Ernzerhof (HSE) function, respectively. Under appropriate uniaxial strain (1%), the bandgap ofh-B2S3can be decreased to 2.8 eV. The carrier mobility can reach 1160 cm2V-1s-1, supporting the fast migration of photo-induced carriers. Most importantly, the band edges of bothh-B2S3ando-B2S3cover the reduction and oxidation levels for water splitting. We explore the process of photocatalytic water splitting onh-B2S3monolayers by analyzing the feasibility of the decomposition of H2O and the generation of H2. The results indicate that the special mesoporous structure of B2S3is helpful for photocatalytic hydrogen production. The new nanomaterial, B2S3, offers great promise as a metal-free photocatalyst due to its tunable bandgaps, its useful band edges, and its other excellent electronic properties.

Theoretical Simulations of Heavy-Atom Kinetic Isotope Effects in Aliphatic Claisen Rearrangement.

The aliphatic Claisen rearrangement of allyl vinyl ether has attracted great interest for its broad applications in chemical synthesis and biosynthesis. Although it is well agreed that this reaction proceeds via a concerted, "chair-like" transition state, certain inconsistencies of kinetic isotope effect (KIE) data between experimental measurements and theoretical simulations or between independent experiments indicate that the nature and mechanism of this important reaction need to be investigated in more detail. In order to verify two independent sets of experimental data, we present theoretical calculations on heavy-atom KIE values of alipahtic Claisen rearrangement, using our recently developed path-integral method with the second-order Kleinert's variational perturbation theory, which goes beyond the traditional method for computing KIE values by employing the Bigeleisen equation. Amazingly, the results demonstrate that both sets of experimental measurements are correct, while the inconsistency originates from the fact that the aliphatic Claisen rearrangement undergoes similar but different mechanisms in gas and solution phases. Different experimental conditions will alter the actual reactant state by tuning the population distribution of reactant conformers. According to the comparison between experimental and theoretical results, a more clear reaction mechanism of aliphatic Claisen rearrangement is revealed.

Surface functional group modification induced partial Fermi level pinning and ohmic contact at borophene-MoS2 interfaces.

Large Schottky barrier at the electric contact interface drastically hinders the performance of two-dimensional (2D) semiconductor devices, because of which it is crucial to develop better methods to achieve the ohmic contact. Recently, a new field effect transistor (FET) device was constructed by the popular 2D channel material MoS2 and an electrode material borophene was detected theoretically, but the large Schottky barrier still existed. Hence, we used surface functional groups modification on the borophene surface to regulate this Schottky barrier, based on ab initio electronic structure calculations and quantum transport simulations. Our study shows that this method makes it possible to obtain tunable metal work functions in a wide range, and the ohmic contact can still be realized. Although van der Waals (vdW) contacts were observed at all the interfaces between the 2D borophene-based metals and the monolayer MoS2, the Fermi level pinning (FLP) effect was still obvious, and existed in our proposed system with the ohmic contact. Moreover, we also discuss the origin of the FLP with varying degrees. It was found that the interface dipole and metal-induced gap states (MIGS) would be responsible for the FLP of vertical and lateral directions, respectively. More precisely, we find that the size of MIGS is dependent on the relative orientation between the functional group and metal-MoS2 interface. This work not only suggests that surface functional group modification is effective in forming ohmic contact with MoS2, but also holds some implication in the fundamental research on metal-semiconductor contacts with the vdW type.

Interpenetrated Metal-Organic Frameworks with ftw Topology and Versatile Functions.

Through an "isoreticular expansion" strategy, a large number of highly porous zirconium-based metal-organic frameworks (Zr-MOFs) have been achieved using extended organic linkers in the past few years. However, interpenetrated Zr-MOFs with ftw topology have scarcely been reported, mainly owing to the used bulky tetratopic linkers that effectively prevent the network interpenetration. Here, we report a new family of zirconium and lanthanide (Ln) MOFs with ftw topology, constructed by hexanuclear Zr or Ln (Ln = Eu, Tb, Gd, Dy, Tm, Yb, Nd, and Er) clusters and a spirobifluorene-center tetracarboxylate linker. Our studies reveal that the isostructural Zr and Ln MOFs are all doubly interpenetrated with ultrahigh thermal and chemical stability. The observed unusual interpenetration can be attributed to the specific geometry of the spirobifluorene-center tetratopic linker. Gas adsorption studies show that the interpenetrated Zr-MOF is still highly porous and exhibits high performance for CO2 storage, which can be attributed to the strong CO2 binding environment contributed by the reduced pore size. In addition, the presented MOFs display strong characteristic luminescence in the UV-vis-NIR region. Moreover, the incorporation of the spiro-center linker into the framework can efficiently produce two-photon-excited photoluminescence with a large action cross-section value, which also benefited from the high packing density of the nonlinear optical chromophore linker in the interpenetrated structure.

Tuning the Connectivity, Rigidity, and Functionality of Two-Dimensional Zr-Based Metal-Organic Frameworks.

Presented herein is a group of highly stable Zr-based metal-organic frameworks with bowl-shaped dihydroanthracene-based tetratopic linkers as building blocks. Structural analysis reveals that these frameworks are all two-dimensional but comprise three distinct connectivities of Zr6 nodes. By using the steric hindrance of the nonplanar linker, the connectivity of Zr6 node can be tuned from 8-c to unusual 4-c. Further, through either one-pot synthesis or postsynthetic linker installation strategies, the connectivity of Zr6 node can be tuned from 8-c to 10-c by the insertion of a secondary linear dicarboxylate linker, from which not only the temperature-dependent flexibility of the structure can be effectively controlled with enhanced rigidity and thermal stability but also a scaffold for postsynthetic metalation of Pd(II) catalyst for Heck coupling reaction is offered.

Exotic magnetism in As-doped α/ß-In2Se3 monolayers with tunable anisotropic carrier mobility.

The two-dimensional (2D) material family is expanding fast as novel metal chalcogenides are being continually fabricated and intriguingly, plenty of them are ideal candidates for future nanoscale electronic and magnetic devices. Based on first-principles calculations, we investigated the electronic and magnetic properties of α/ß-In2Se3 monolayers. We find singularities of density of states appear in the valence band and hole doping (such as a Se atom substituted by a lower valence atom) can induce various ferromagnetic phase transitions in the α/ß-In2Se3 monolayers. In particular, replacement by arsenic at the anion site can enhance ferromagnetism and drive α-In2Se3 to be a robust half-metal and ß-In2Se3 to be a bipolar magnetic semiconductor. Then, we proposed spin-polarized field-effect transistors based on α-In2Se3 and a bipolar field-effect spin-filter based on ß-In2Se3. Besides, we also discussed the influences of the molecules in air on the device performance such as carrier mobility. We found that the adsorption of either O2 or H2O on α/ß-In2Se3 induced changes in hole mobility in different directions. These findings reveal a new road to electronic and magnetic modulations in 2D materials.

Enhanced photocatalysis for water splitting in layered tin chalcogenides with high carrier mobility.

Due to their proper band gaps (between 1.40 eV and 2.34 eV), newly fabricated tin monochalcogenides (SnX, X = S, Se) and dichalcogenides SnX2, whose monolayer formation energies are much smaller than MoS2, are promising materials for harvesting visible light. Moreover, the anisotropic carrier mobility is up to 2486.93 cm2 V-1 s-1 for SnSe and 2181.96 cm2 V-1 s-1 for SnS2. By applying low tensile strain, the band edge of SnX can be lowered to meet the criteria for water splitting. Meanwhile, the photo-generated exciton binding energies are pretty low, which indicates that the electron-hole can separate efficiently, and may lead to remarkable activity for photocatalysis. Promisingly, it is possible to stack SnS and SnS2 to fabricate a vertical heterostructure (VHT). According to band analysis, we found that the global valence and conduction bands are from SnX and SnX2, respectively. Due to the weak interaction between the two monolayers, the optical gaps can slightly decrease in the two monolayers compared to those in the corresponding isolated ones. Therefore, the VHT can meet the two primary conditions of a photocatalyst for water splitting to generate H2 in SnX and O2 in SnX2. The strong electronegativity difference between the two layers develops an effective potential gradient between the SnS and SnS2 layers, which evokes an effective electric field between them. Thus, it is of benefit for quick charge separation and inter-layer charge transfer. High efficiency of light harvesting can be realized, and improved photocatalytic efficiency.

The Syntheses, Characterization and Crystal Structures of a Series of Heterocyclic ß-Diketones and Their Isoxazole Compounds.

BACKGROUND: In the field of coordination chemistry, the introduction of heterocyclic substituents into the structure of ß-diketone enables ligand to produce multiple coordination sites. The adoption of small steric oxime group into the structure of heterocyclic ß-diketone by Schiff-base condensation will further increase coordination sites and facilitate the generation of polynuclear structures. OBJECTIVE: A series of ß-diketones (2a-2c) containing different heterocycles such as pyridine, thiophene and furan and their corresponding isoxazole compounds (3a-3c) were synthesized. MATERIALS AND METHODS: The Claisen condensations were investigated in a solvent-free rheological phase system at room temperature to obtain heterocyclic ß-diketones 2a-2c, which further reacted with hydroxylamine hydrochloride to obtain heterocyclic isoxazoles 3a-3c. All these compounds were well characterized by EA, IR, 1H NMR and X-ray crystal diffraction to confirm the structures. Synthetic mechanisms of compounds and the effects of different heterocycles on reactivity were discussed deeply. RESULTS: 1H NMR indicated that these ß-diketones do not exist as a total diketonic form but an equilibration between diketone and enol forms in CDCl3 solvent, in which the enol form accounts for 98.0% in 2a, 94.3% in 2b, 95.5% in 2c. While the crystal structures of 2a-2c showed that the reaction allows to isolate diketones in solid state. Crystal structures of 3a-3c showed that the neutral ß-ketone oximes resonate and cyclize to form the target heterocyclic isoxazoles. CONCLUSION: SN1 nucleophilic substitution mechanism of Claisen ketoester condensation was proposed for the syntheses of 2a-2c, and SN1 single molecule nucleophilic substitution reaction mechanism was put forward for 3a-3c.

General Component Analysis (GCA): A new approach to identify Chinese corporate bond market structures.

PCA has been widely used in many fields to detect dominant principle components, but it ignores the information embedded in the remaining components. As a supplement to PCA, we propose the General Component Analysis (GCA). The inverse participation ratios (IPRs) are used to identify the global components (GCs) and localized components (LCs). The mean values of the IPRs derived from the shuffled data are taken as the natural threshold, which is exquisite and novel. In this paper, the Chinese corporate bond market is analyzed as an example. We propose a novel network method to divide time periods based on micro data, which performs better in capturing the time points when the market state switches. As a result, two periods have been obtained. There are two GCs in both periods, which are influenced by terms to maturity and ratings. Besides, there are 382 LCs in Period 1 and 166 LCs in Period 2. In the LC portfolios there are two interesting bond collections which are helpful to understand the thoughts of the investors. One is the supper AAA bond collection which is believed to have implicit governmental guarantees by the investors, and the other is the overcapacity industrial bond collection which is influenced by the supply-side reform led by the Chinese government. GCA is expected to be applied to other complex systems.

Carbenoxolone inhibits mechanical stress-induced osteogenic differentiation of mesenchymal stem cells by regulating p38 MAPK phosphorylation.

The aim of the present study was to explore the effects of pannexin1 (Px1) protein channels on osteogenic differentiation of mesenchymal stem cells (MSCs) under mechanical stress stimulation. MSCs were isolated from Sprague Dawley rats (3 weeks old, weighing 100-120 g) and cultured in vitro. A safe concentration of carbenoxolone was determined (CBX, an inhibitor of Px1 channels; 100 µM) on MSCs using the Cell Counting Kit-8 (CCK8) method. MSCs were divided into 6 groups: Control, stress (4,000 µ strain), and stress following 3, 6, 12, and 24 h pretreatment with CBX. Stress groups were stimulated with mechanical stress for 15 min. Alkaline phosphatase (ALP) activity, type I collagen expression, intracellular calcium ion (Ca2+) concentration, Px1 expression, p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated phosphorylation were determined. ALP activity was increased in the stress group, and this was prevented by pretreatment with CBX. Similarly, stress-induced increases in type I collagen expression, Ca2+ concentration, Px1 expression, and p38 MAPK phosphorylation decreased in the presence of CBX. ERK phosphorylation was decreased by stress, however was not affected by CBX treatment. Altogether, the results suggest that mechanical stress promoted the osteogenic differentiation of MSCs, and this promotion was inhibited by pretreatment with CBX, possibly through regulating the phosphorylation of p38 MAPK.

Pressure induced photoluminescence modulation in a wide range and synthesis of monodispersed ternary AgCuS nanocrystal based on Ag2S nanocrystals.

Binary Ag2S nanocrystals (NCs) have many potential optical applications because of their low toxicity, narrow direct band gaps and near-infrared photoluminescence (PL) with high emission efficiency. However, due to its small exciton Bohr radius (2.2 nm), the PL spectra of Ag2S NCs can only be modulated below ∼1200 nm with increasing particle size. Meanwhile, ternary silver copper chalcogenides (AgCuX, X = S, Se) have also attracted increased attention in recent years. Temperature-dependent structural phase transformation leads electrical transport to exhibit fascinating transitions between p and n type conduction, which makes AgCuS and AgCuSe ideal materials for diode or transistor devices. Nevertheless, the traditional method to synthesize these materials is mainly through melting the mixture of Ag, Cu and S/Se powder under extremely high reaction temperatures (973-1373 K) and long reaction time, forming a bulk product. Therefore, the synthesis of high quality monodispersed and size-tunable AgCuS or AgCuSe NCs is still a challenge. To address these issues, in this paper, we report using Ag2S NCs as a template, a method to synthesize monodispersed and size-tunable ß-AgCuS NCs via ion exchange and diffusion processes. Similarly, monodispersed ß-AgCuSe NCs were also synthesized by this simple and reproducible strategy. This synthetic method opens new avenues for investigating the size-, morphology- and temperature-dependent phase transitions of these ternary AgCuS and AgCuSe materials. Thus, the corresponding electrical transport between p and n type conduction can be studied in the future. Furthermore, we systematically investigated the pressure-dependent PL properties and band gap modulation of monodispersed Ag2S NCs using in situ high pressure PL and absorption spectroscopy. We found that the PL peak of 6.0 nm for Ag2S NCs could be easily adjusted from ∼1200 to 1900 nm with increasing pressure from 0 to 5.1 GPa, which greatly extends the wavelength range of the PL peak beyond that of other approaches.