Non-stoichiometric Ratio Research Articles

Highly Efficient and Stable CsPbI3 Perovskite Quantum Dots Light-Emitting Diodes Through Synergistic Effect of Halide-Rich Modulation and Lattice Repair.

Currently, CsPbI3 quantum dots (QDs) based light-emitting diodes (LEDs) are not well suited for achieving high efficiency and operational stability due to the binary-precursor method and purification process, which often results in the nonstoichiometric ratio of Cs/Pb/I. This imbalance leads to amounts of iodine vacancies, inducing severe non-radiative recombination processes and phase transitions of QDs. Herein, red-emitting CsPbI3 QDs are reported with excellent optoelectronic properties and stability based on the synergistic effects of halide-rich modulation passivation and lattice repair. First, a ternary-precursor method is employed to better control the feed ratio of Cs/Pb/I and create a halide-rich environment. Second a solvent-free solid-liquid reaction employing a multifunctional guanidinium iodide (GAI) additive is used after purification to repair iodine vacancies and partially replace surface Cs atoms, thereby effectively modifying its tolerance factor. Additionally, this short-chain GA+ can be used as the surface ligand to improve the conductivity of the QDs and suppress trap-assisted non-radiative Auger recombination. Consequently, PeLEDs based on GAI-QDs exhibit a great maximum external quantum efficiency (EQE) of 27.1% and an operational half-lifetime (T50) of 1001.1min at an initial luminance of 100cdm-2.

Enhanced thermophysical and mechanical properties of gadolinium zirconate ceramics via non-stoichiometric design

Rare-earth zirconate ceramics are potential materials for thermal barrier coatings due to their low thermal conductivity and excellent structural stability. However, the low thermal expansion coefficient and fracture toughness limit their application and further improvements are needed. In this work, non-stoichiometric gadolinium zirconate ceramics with fluorite phase structure were successfully prepared using solid-state reaction method. HRTEM, iDPC-STEM, and in-situ XRD were employed to investigate nanostructure, lattice defects, and phase stability. The non-stoichiometric ratio introduces more defects and forms special nanostructures, enhancing the thermophysical properties of gadolinium zirconate ceramics. The non-stoichiometric gadolinium zirconate ceramics have lower phonon thermal conductivity with higher hardness and fracture toughness compared to stoichiometric ratio ceramics. In addition, the non-stoichiometric gadolinium zirconate ceramics exhibit excellent structural stability in a wide temperature range. These performances provide further applications for non-stoichiometric gadolinium zirconate ceramics as thermal barrier coatings.

Tailoring of bulk oxygen vacancies in BiVO4 photoanodes via crystallization dynamics engineering for boosted photoelectrochemical water oxidation

Oxygen vacancies (Ov) in metal oxides is of critical importance in photoelectrochemical water splitting due to its unique capability on modulating the carrier density and charge separation. A challenge remains however currently on generating bulk Ov in metal oxides since surface Ov faces awkward photochemical instability. We herein demonstrate a facile way of creating the bulk Ov in Mo:BiVO4 (MBVO) photoanodes simply from altering Bi/V in MBVO with non-stoichiometric ratio, which significantly modifies the crystallization dynamics of MBVO and tailors the amount of bulk Ov in MBVO. It is proposed that the bulk OV significantly increase the majority carrier density due to the additional photoexcitation of OV, and reduce the recombination constant (krec) due to the efficient trapping of excess holes in the stable deep-level inter-band Ov2+ states. It is further demonstrated that the tailored bulk OV leads to a 1.6-fold increased photocurrent density and 50 h operational stability at 1.23 VRHE, indicating the potentials for tailoring bulk Ov in photoanodes via crystallization dynamics engineering for viable photoelectrochemical water splitting.

Accelerated peroxymonosulfate activation over defective perovskite with anchored cobalt nanoparticles for organic contaminant removal

In this study, a novel perovskite oxide (Co@D-PBSC) for activation peroxymonosulfate (PMS) to degrade organic pollutants in wastewater was developed. Cobalt nanoparticles (Co NPs) and oxygen vacancies (OVs) were introduced to the perovskite oxide lattice via a non-stoichiometric ratio and separate-out strategy. The OVs and Co NPs provided abundant active sites for the activation of PMS and the generation of reactive oxygen species. The Co metal-OVs bridge promote the adsorption of PMS, meanwhile, Co nanoparticles accelerate the Co2+/Co3+ redox cycle, resulting in the production of the main reactive substance, sulfate radicals (SO4•−). The results of catalytic experiments showed that 85 % of ofloxacin (OFX) degradation efficiency was obtained within 1 min at 0.1 g/L Co@D-PBSC, 0.3 g/L PMS, 20 mg/L OFX (150 mL), and solution pH 7.0, which indicated that Co@D-PBSC/PMS system exhibits excellent performance. This work demonstrated an efficient perovskite catalyst for PMS activation in wastewater treatment and provided a useful catalyst design strategy for the advanced oxidation processes (AOPs).

Off-Stoichiometry of Sodium Iron Pyrophosphate as Cathode Materials for Sodium-Ion Batteries with Superior Cycling Stability.

As one of the important devices for large-scale electrochemical energy storage, sodium-ion batteries have received much attention due to the abundant resources of raw materials. However, whether it is a base station power source, an energy storage power station, or a start-stop power supply, long energy cycle life (more than 5000 cycles), high stability, and safety performance are application prerequisites. Regrettably, currently, few sodium-ion batteries can meet this requirement, mainly due to shortcomings in positive electrode performance. We report a sufficiently stable sodium-ion battery cathode material, Na2Fe0.95P2O7, that retains 97.5% capacity after 5000 charge/discharge cycles. The use of nonstoichiometry in the lattice enables simultaneous modification of the crystal and electronic structure, promoting Na2Fe0.95P2O7 to be extremely stable while still being able to achieve a capacity of 92 mAh g-1 and stable cycling at high temperatures up to 60 °C. Our results confirm the positive effect of nonstoichiometric ratios on the performance of Na2Fe0.95P2O7 and provide a reliable idea to promote the practical application of sodium-ion batteries.

From theory to application: Innovative ice-phobic polyurethane coatings by studying material parameters, mechanical insights, and additives

This investigation introduces new insights into the influence of material parameters on the anti-icing properties of polyurethane (PU) coatings, encompassing chemical characteristics, cross-link densities, mechanical analysis, and additive diversity. To comprehensively address these aspects, a meticulous exploration was conducted to delve into the effects of these parameters on wettability and icephobicity. To fabricate the PU coatings, three distinct acrylic polyols with various hydroxyl content along with two widely employed aliphatic isocyanates boasting diverse %NCO values were utilized. By employing stoichiometric and non-stoichiometric ratios, an array of coatings with different crosslink densities and mechanical properties was fabricated. The principal influence of crosslink density alterations in PU coatings on ice nucleation temperature and ice adhesion strength emerged distinctly, underpinned by the establishment of hydrogen bonds between water molecules and polar functional groups within the coating, coupled with the appearance of a quasi-liquid layer (QLL). The mechanical properties, wettability characteristics, and surface roughness of the coatings were examined and it was clearly demonstrated that Young's modulus and physicochemical properties play significant roles in the characteristics of ice adhesion strength. In particular, lower Young's modulus in the samples was associated with reduced ice adhesion, albeit with compromised durability. In the next step of this investigation, the matrix demonstrating optimal mechanical properties and icephobicity was subjected to surface energy adjustment. This was accomplished by introducing various concentrations of both fluorinated and non-fluorinated additives. This adjustment led to a significant reduction of ice adhesion strength, measuring less than 100 Kpa as an icephobic PU coating. Nevertheless, it was observed that the effectiveness of the fluorinated additives diminished after repetitive icing-deicing cycles, while the non-fluorinated additive maintained its influence on ice adhesion strength even after numerous cycles. The interplay between material attributes, mechanical properties, and additive influences has been meticulously unraveled, charting a course for further advancements in the pursuit of robust icephobic coating.

Macromolecular Crowding Effect on Chitosan-Hyaluronic Acid Complexation and the Activity of Encapsulated Catalase.

The associative phase separation of charged biomacromolecules plays a key role in many biophysical events that take place in crowded intracellular environments. Such natural polyelectrolyte complexation and phase separation often occur at nonstoichiometric charge ratios with the incorporation of bioactive proteins, which is not studied as extensively as those complexations at stoichiometric ratios. In this work, we investigated how the addition of a crowding agent (polyethylene glycol, PEG) affected the complexation between chitosan (CS) and hyaluronic acid (HA), especially at nonstoichiometric ratios, and the encapsulation of enzyme (catalase, CAT) by the colloidal complexes. The crowded environment promoted colloidal phase separation at low charge ratios, forming complexes with increased colloidal and dissolution stability, which resulted in a smaller size and polydispersity (PDI). The binding isotherms revealed that the addition of PEG greatly enhanced the ion-pairing strength (with increased ion-pairing equilibrium constant Ka from 4.92 × 104 without PEG to 1.08 × 106 with 200 g/L PEG) and switched the coacervation from endothermic to exothermic, which explained the promoted complexation and phase separation. At the stoichiometric charge ratio, the enhanced CS-HA interaction in crowded media generated a more solid-like coacervate phase with a denser network, slower chain relaxation, and higher modulus. Moreover, both crowding and complex encapsulation enhanced the activity and catalytic efficiency of CAT, represented by a 2-fold increase in catalytic efficiency (Kcat/Km) under 100 g/L PEG crowding and CS-HA complex encapsulation. This is likely due to the lower polarity in the microenvironment surrounding the enzyme molecules. By a systematic investigation of both nonstoichiometric and stoichiometric charge ratios under macromolecular crowding, this work provided new insights into the complexation between natural polyelectrolytes in a scenario closer to an intracellular environment.

Preparation of lithium ferromanganese phosphate by non-stoichiometric strategy

LixFexMn1-xPO4 exhibits low production costs, environmental friendliness, high energy density, thermal stability, and cycling stability in lithium-ion batteries (LIBs), presenting broad application prospects. Furthermore, studies have shown that adopting a non-stoichiometric ratio strategy can reduce particle size, decrease anti-site defects, and generate a conductive impurity phase on the material surface. This leads to an enhancement in the electrochemical performance of the material, making it an effective approach to achieving high-performance olivine-type cathode materials. In this study, three materials were successfully prepared using the solid-phase method: Li1.05Fe0.5Mn0.475PO4/C, Li1.05Fe0.5Mn0.5PO4/C, and Li1.05Fe0.475Mn0.5PO4/C. The physical properties of the materials were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The electrochemical performance including specific capacity, rate performance, and cycling performance were studied through charge-discharge tests, with Li1.05Fe0.5Mn0.475PO4/C exhibiting the best specific capacity at all rates. At rates of 0.1 C, 0.5 C, 1 C, 2 C, and 5 C, its average reversible specific capacities were 143.5, 129.5, 122.1, 112.8, and 97.3 mAh·g−1, respectively. Furthermore, differences in electrochemical performance of three materials were discussed in detail through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

An efficient and robust Co-free BaFeO3-based oxygen electrode for protonic ceramic electrochemical cells

Protonic ceramic electrochemical cells (PCECs) are promising devices for sustainable energy conversion and storage with high efficiency and low cost. However, the application of PCECs is limited by the scarcity of oxygen electrode materials with excellent oxygen reduction/evolution reaction (ORR/OER) activity and robust durability. In this investigation, perovskite oxide with specific non-stoichiometric ratios, namely Ba0.9Sr0.05La0.05Fe0.8Zn0.1Y0.1O3 (BSLFZY) are synthesized using a sol-gel method, and electrochemically evaluated as oxygen electrodes for PCECs. The structural and chemical stability of the synthesized material is explored and analyzed through X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterizations. Surface catalytic activity is assessed using X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG), and oxygen temperature-programmed desorption techniques (O2-TPD). Additionally, the electronic conductivity results demonstrate the suitability of BSLFZY for application in PCECs. The electrochemical performance of the material is estimated using a homemade Ni-BZCYYb/BZCYYb cell with a BSLFZY oxygen electrode. Electrochemical impedance spectra within a specific temperature range are analyzed using the distribution of relaxation times (DRT) method. The results offer valuable insights into the underlying reasons for long-term electrochemical performance degradation in fuel cell (FC) mode. These results present the potential of BSLFZY for practical applications in PCECs, highlighting its excellent electrochemical performance and durability.

Multi-color luminescent material with Mn2+/Mn4+ non-stoichiometric ratio doped octahedra and its anti-counterfeiting applications

Mn ions in different valence states can emit light of different colors in an octahedral coordination environment, which is conducive to the development of a single matrix with multi-color luminescence and applications in the field of anti-counterfeiting. The dual mode multi-color luminescent material CaSb2O6: Mn has been successfully synthesized using a single Mn source in the atmosphere. The CaSb2O6 matrix itself can also absorb 285 nm UV light, emit blue light, and show a long afterglow phenomenon. Both Mn4+ and Mn2+ ions will appear in the [SbO6] octahedra, whether the Mn source adopts MnCO3 or MnO2. The Mn4+ ion exhibits red emission upon UV excitation at 347 nm. The Mn2+ ion can emit a bright green light at 285 nm excitation while exhibiting a long afterglow phenomenon. In this study, the Mn2+ doped octahedron showed unique green emission and broadens the range of its photoluminescence (PL) wavelength. The performance of the material's long afterglow properties on the digital codes demonstrates its potential for dynamic anti-counterfeiting.

Tuning magnetocrystalline anisotropy by Au ion induced defects in NiO thin films

Intercalations and doping effectively induce room-temperature ferromagnetism in antiferromagnetic NiO thin films. This report investigates the defect-controlled ferromagnetic properties of Au ion implanted highly crystalline NiO thin films at different ion fluences. Low energy heavy ion irradiation leads to preferential sputtering of Ni and O atoms that create various kinds of vacancies and interstitial defect states within the matrix. These defect states are responsible for bandgap narrowing and changing the crystallite size and show the defect luminescence in the NiO thin films. It has been observed that the intrinsic Ni and O defects with the non-stoichiometric ratio of these atoms during crystal growth, resulting in uncompensated spins, induce the ferromagnetic properties in the pristine sample and are further modulated with ion fluences. The presence of defects gives rise to energy variations due to the modification of the magnetic environment of Ni ions in the lattice and tune the blocking temperature and magnetocrystalline anisotropy. The magnetocrystalline anisotropy constant (K) reaches its maximum at 70 erg/cm3 with ion fluence and decreases at the highest fluence because of the suppression of exchange interaction by a large number of defect centers. The modulation of anisotropy in NiO thin films is intricately linked to crystallite size, bandgap narrowing, blocking temperature, and the magnetization mechanism, which is a direct result of defect concentrations in the material.

The Importance of Nonstoichiometric Ratio of Reactants in Organic Synthesis

The Importance of Nonstoichiometric Ratio of Reactants in Organic Synthesis

Investigation of the properties of ZrC nanopowder synthesized by the carbothermal reduction method using phenolic resin

AbstractOwing to economic reasons and the morphology of the surface of particles, carbothermal reduction is a suitable method for the synthesis of the desired materials. In this research, ZrC nanopowder was synthesized using phenolic resin as the carbon source and ZrO2 powder as the source of zinc by the carbothermal method. ZrO2 powder was milled for 1, 2, 3, 4, 6, and 7 h followed by combining with phenolic resin and ethanol with stoichiometric and nonstoichiometric ratios, and then the samples were pyrolyzed for 60 min at 800°C. Then, the samples were heat treated in an argon atmosphere in two stages at 1,600°C for 60 and 90 min. XRD and FE‐SEM were used to investigate the microstructure of the samples. By increasing the molar ratio and increasing the heat treatment time, the ZrC phase content in the samples increased so that the highest amount of ZrC phase was observed in the samples with the carbon to zirconium ratios of 1:6 and 1:9 and the holding time of 90 min. By increasing the heat treatment time, the average size of ZrC particles increased from 130 to 180 nm and the size of crystallites increased from 36 to 46 nm.

Investigation effect of Lu-substitution on structural, morphological, magnetic, and dielectric properties of BaM hexaferrite synthesized using a co-precipitation method

In this paper, we synthesized Lu-substituted M-type barium ferrites (BaLuxFe12-xO19, x = 0, 0.2, 0.4, 0.6, 0.8) by chemical co-precipitation using a non-stoichiometric ratio of raw materials. We investigated their structure, XPS, and EDX spectra, morphology, and magnetic and dielectric properties. The XRD patterns showed that the diffraction peaks shifted toward a lower angle and the lattice constant ratio (c/a) was less than 3.98, which was within the allowable range of magneto-plumbite structure. XPS and EDX spectra confirmed the presence of O, Fe, Ba, and Lu elements in the samples. SEM images revealed that the ceramic samples sintered at 1330 °C had a regular and obvious hexagonal structure. Lu substitution promoted grain growth, with an average grain size increase of 163% and a maximum grain size of 21.77 µm. Hysteresis loops indicated the formation of a multi-domain structure in the samples. The coercivity decreased from 2035.82 Oe to 574.84 Oe and the saturation magnetization decreased as well but still exceeded 58 emu/g. The dielectric constants of all the samples were in the order of 103 to 104 and the substitution of Lu significantly increased it to about 16k. The tangent loss could be maintained below 0.5, with a minimum of approximately 0.1. The Lu-substitution barium ferrites with high saturation magnetization, low coercivity, high dielectric constant, and low tangent loss coexistence may be a potential candidate for application in low-frequency wireless communication with miniaturization and multifunction.

A new Ni-based superconductor with tunable critical temperature

The search for new 3d transition metal superconductors, especially Ni-based superconductors, is of great significance for understanding the mechanism of high temperature superconductivity. Based on inorganic material database, we found a new superconductor Mo2NiB2 through structural design. The crystal structure of Mo2NiB2 was analyzed by synchrotron radiation, Mo2NiB2 is a superconductor with a quasi-one-dimensional structure and also a Ni-based superconductor with a new structure. We report that the Mo2NiB2 exhibits superconductivity of 4 K, which is a typical type Ⅱ superconductor, and the non-stoichiometric ratio of Ni sites can increase the superconducting critical temperature of Mo2NiB2.

Boosting the high-rate performance of lithium-ion battery anodes using MnCo2O4/Co3O4 nanocomposite interfaces.

Herein, a mesoporous MnCo2O4/Co3O4 nanocomposite was fabricated using a polyvinylpyrrolidone (PVP)-assisted hydrothermal synthesis method by maintaining only the non-stoichiometric ratio of Mn and Co (2 : 6), leading to an extra phase of Co3O4 coupled with MnCo2O4. Microstructural analysis showed that the obtained sample has a uniform nanowire-like morphology composed of interconnected nanoparticles. The stoichiometric ratio (2 : 4) was maintained to synthesize pure MnCo2O4 for comparative analysis. However, the obtained structure of pure MnCo2O4 was found to be irregular and fragile. After their employment as anode-active materials, the nanocomposite electrode showed superior high rate capability (1043.8 mA h g-1 at 5C) and long-term cycling stability (773.6 mA h g-1 after 500 cycles at 0.5C) in comparison to the pure MnCo2O4 electrode (771.5 mA h g-1 at 5C and 638.9 mA h g-1 at 0.5C after 500 cycles). It was believed that the extra phase of Co3O4 may also participate in the electrochemical reactions due to its high electrochemically active nature. Benefiting from the appealing architectural features and striking synergistic effect, the integrated MnCo2O4/Co3O4 nanocomposite anode exhibits excellent electrochemical properties and high cycle stability for LIBs.

Synergistic effect between ZnCo2O4 and Co3O4 induces superior electrochemical performance as anodes for lithium-ion batteries.

The current work describes a facile synthesis of spinel-type ZnCo2O4 along with an additional phase, Co3O4, by simply maintaining a non-stoichiometric ratio of Zn and Co precursors. Pure ZnCo2O4 and Co3O4 were also synthesized using the same method to compare results. The obtained morphologies of samples show that small-sized nanoparticles are interconnected and form a porous nanosheet-like structure. When used as anode materials for Li-ion batteries, the ZnCo2O4/Co3O4 nanocomposite electrode exhibits a highly stable charge capacity of 1146.2 mA h g-1 at 0.5C after 350 cycles, which is superior to those of other two pure electrodes, which can be attributed to its optimum porosity, synergistic effect of ZnCo2O4 and Co3O4, increased active sites for Li+ ion diffusion, and higher electrical conductivity. Although the pure Co3O4 electrode displayed a much higher rate capability than the ZnCo2O4/Co3O4 nanocomposite electrode at all investigated current rates, the Co3O4 morphology apparently could not withstand long-term cycling, and the electrode became pulverized due to the repeated volume expansion/contraction, resulting in a rapid decrease in the capacity.

Perovskite Oxide as A New Platform for Efficient Electrocatalytic Nitrogen Oxidation

AbstractElectrocatalytic nitrogen oxidation reaction (NOR) offers an efficient and sustainable approach for conversion of widespread nitrogen (N2) into high‐value‐added nitrate (NO3−) under mild conditions, representing a promising alternative to the traditional approach that involves harsh Haber–Bosch and Ostwald oxidation processes. Unfortunately, due to the weak absorption/activation of N2 and the competitive oxygen evolution reaction, the kinetics of NOR process is extremely sluggish accompanied with low Faradaic efficiencies and NO3− yield rates. In this work, an oxygen‐vacancy‐enriched perovskite oxide with nonstoichiometric ratio of strontium and ruthenium (denoted as Sr0.9RuO3) was synthesized and explored as NOR electrocatalyst, which can exhibit a high Faradaic efficiency (38.6 %) with a high NO3− yield rate (17.9 μmol mg−1 h−1). The experimental results show that the amount of oxygen vacancies in Sr0.9RuO3 is greatly higher than that of SrRuO3, following the same trend as their NOR performance. Theoretical simulations unravel that the presence of oxygen vacancies in the Sr0.9RuO3 can render a decreased thermodynamic barrier toward the oxidation of *N2 to *N2OH at the rate‐determining step, leading to its enhanced NOR performance.

Perovskite Oxide as A New Platform for Efficient Electrocatalytic Nitrogen Oxidation.

Electrocatalytic nitrogen oxidation reaction (NOR) offers an efficient and sustainable approach for conversion of widespread nitrogen (N2 ) into high-value-added nitrate (NO3 - ) under mild conditions, representing a promising alternative to the traditional approach that involves harsh Haber-Bosch and Ostwald oxidation processes. Unfortunately, due to the weak absorption/activation of N2 and the competitive oxygen evolution reaction, the kinetics of NOR process is extremely sluggish accompanied with low Faradaic efficiencies and NO3 - yield rates. In this work, an oxygen-vacancy-enriched perovskite oxide with nonstoichiometric ratio of strontium and ruthenium (denoted as Sr0.9 RuO3 ) was synthesized and explored as NOR electrocatalyst, which can exhibit a high Faradaic efficiency (38.6 %) with a high NO3 - yield rate (17.9 μmol mg-1 h-1 ). The experimental results show that the amount of oxygen vacancies in Sr0.9 RuO3 is greatly higher than that of SrRuO3 , following the same trend as their NOR performance. Theoretical simulations unravel that the presence of oxygen vacancies in the Sr0.9 RuO3 can render a decreased thermodynamic barrier toward the oxidation of *N2 to *N2 OH at the rate-determining step, leading to its enhanced NOR performance.

Direct Synthesis of Mixed-Metal Paddle-Wheel Metal-Organic Frameworks with Controlled Metal Ratios under Ambient Conditions.

Currently, synthesizing mixed-metal metal-organic frameworks (MM-MOFs) in a single step remains a challenge due to the varying reactivities of different metal cations. This often results in the formation of mixtures of monometallic MOFs or MM-MOFs with nonstoichiometric metal ratios. A promising approach to overcoming this issue is the controlled precursor method, which uses prebuilt polynuclear complexes with structures similar to the secondary building units (SBUs) of the desired MOFs. In this study, we report that metal acetates can serve as natural prebuilt SBUs, enabling the controlled synthesis of MBDs ([M2(BDC)2DABCO]n, M = metal, BDC = 1,4-benzenedicarboxylic acid, DABCO = 1,4-diazabicyclo[2,2,2]octane) under ambient conditions. By exploiting the fact that metal acetates readily form soluble paddle-wheel dimers similar to the SBUs of MBDs, we achieve the direct synthesis of mixed-metal MBDs at room temperature. The metal ratios (Zn, Co, and Ni) in the resulting MBDs are controllable, and the production yields exceed 90%. The use of metal acetates facilitates the fast and uniform nucleation of MBDs, regardless of the metal cations involved. This similarity in nucleation rates leads to the formation of bimetallic and trimetallic MBDs with predefined metal ratios and homogeneous metal distribution while maintaining the quality of the MOFs. Importantly, this strategy offers an efficient pathway for synthesizing mixed metal MBDs using stoichiometric amounts of metal salts without toxic additives, high energy consumption, and complex synthesis steps.