Low Operating Temperature Research Articles

Advancements in printed components for proton exchange membrane fuel cells: A comprehensive review

Proton Exchange Membranes (PEM) are a promising technology for fuel cells and electrolyzer cells, in line with societal goals for clean and sustainable fuel conversion and generation, respectively, in a vast field of applications. PEM fuel cell (PEMFC) technology has an important advantage for energy conversion applications, because it requires a lower operating temperature and is lighter and more compact than other technologies, which makes it ideal for portable and transportation applications. However, open issues remain to be addressed for PEMFC that hinder their widespread adoption, both on the technical side, such as too high operational temperature range, cell efficiency, and long-term stability, as well as on the industrial side with implementation issues, material and device component availability, and cost. PEM technology research usually focuses on the synthesis of novel materials such as non-noble metal catalysts and non-halogenated membranes. In parallel, developing high-throughput and cost-effective manufacturing methods for components, in particular Membrane Electrode Assembly (MEA), can also lift an important barrier to their mass production, thus contributing to the same goals and securing industrial provision. From this perspective, printing technologies such as spray coating, inkjet printing, and screen printing have emerged as promising approaches with the required precision and scalability. This review covers recent advancements and developments in advanced PEMFC technology manufacturing, with a focus on 2D printing methodologies to fabricate some or all of the MEA components. Leveraging these techniques as simplified large-area manufacturing methods for PEM technology can become a more viable and industrially attractive solution. This work presents a comparison study addressing the key progress indicators both in process and in characterization to build a working framework in which both scientists, engineers and manufacturers can collaborate toward the industrial implementation of this emergent field.

Lithium fluorosulfonate-induced low-resistance interphase boosting low-temperature performance of commercial graphite/LiFePO4 pouch batteries

The performance of Li-ion batteries (LIBs) at sub-ambient temperatures is limited by the resistive interphases due to electrolyte decomposition, particularly on the anode surface. In this study, lithium fluorosulfonate (LFS) was added to commercial electrolytes to enhance the low-temperature electrochemical performance of LiFePO4 (LFP)/graphite (Gr) pouch cells. The addition of LFS significantly reduced the charge transfer resistance of the anode, substantially extending the cycle life and discharge capacity of commercial LFP/Gr pouch cells at −10 and −30 °C. Compared with the capacity retention rate of the baseline electrolyte at −10 °C (80 % after 25cycles), the capacity retention rate of the LFS electrolyte after 100 cycles under 0.5 C/0.5 C was retained at 94 %. Further mechanistic studies showed that the LFS additive induced the formation of a solid electrolyte interphase (SEI) film comprising inorganic-rich LiF, Li2SO4, and additional organic fluorides and sulfides to maintain good stability at the Gr/electrolyte interface during low-temperature operation. LFS suppressed electrolyte decomposition by forming a robust and low-resistance SEI film on the anode. These results demonstrate that LFS is a promising electrolyte additive for low-temperature LFP/Gr pouch cells.

Integrating capture and methanation of CO2 using physical mixtures of Na-Al2O3 and mono-/ bimetallic (Ru)Ni/Pr-CeO2

The integrated capture and methanation of CO2 is hereby realized via the use of physical mixtures of a 12 % Na2O/Al2O3 adsorbent and either a monometallic (10 % Ni/Pr-CeO2) or a bimetallic (1 % Ru, 10 % Ni/Pr–CeO2) catalyst. The effect of the weight ratio between the catalyst and the adsorbent components is studied and it is found to exert a great influence in the reaction kinetics and the CH4 production capacity, with the 1:3 catalyst: adsorbent weight ratio (2.5 wt% Ni for both physically mixed materials and 0.25 wt% Ru for the bimetallic material) providing the highest CH4 yield. It is further shown that the materials offer high activity, stability and CH4 selectivity at just 300 °C, even under the co–presence of O2 and H2O during CO2 adsorption, a fact attributable to the preservation of the Ni-CeO2 contact, which is known to afford a high reducibility to the catalytically active Ni phase. The presence of Ru can further enhance the material reducibility and activity under low operation temperatures and catalyst: adsorbent weight ratios, while also mitigating the negative effect of the O2 and H2O presence in the adsorption feed. A CH4 yield of 0.24 mmol/g after 10 consecutive cycles of CO2 adsorption (under O2 and H2O containing gas) and methanation is achieved for the monometallic Ni-based physically mixed material, compared to 0.29 mmol/g in the case of the Ru–Ni bimetallic physically mixed material.

Four-channel optically pumped magnetometer for a magnetoencephalography sensor array.

We present a novel four-channel optically pumped magnetometer (OPM) for magnetoencephalography that utilizes a two-color pump/probe scheme on a single optical axis. We characterize its performance across 18 built sensor modules. The new sensor implements several improvements over our previously developed sensor including lower vapor-cell operating temperature, improved probe-light detection optics, and reduced optical power requirements. The sensor also has new electromagnetic field coils on the sensor head which are designed using stream-function-based current optimization. We detail the coil design methodology and present experimental characterization of the coil performance. The magnetic sensitivity of the sensor is on average 12.3 fT/rt-Hz across the 18 modules while the average gradiometrically inferred sensitivity is about 6.0 fT/rt-Hz. The sensor 3-dB bandwidth is 100 Hz on average. The on-sensor coil performance is in good agreement with the simulations.

Highly improved ionic conduction in reverse spinel structured CoAl2O4 and ZnO heterostructure through interfacial disordering

For ceramic fuel cells with low temperatures operation (LT-CFCs; 350°-550 °C), increasing the ionic conductivity and improving the oxygen reduction electrocatalytic activity response at low operating temperatures would be highly desired. This Study presents a novel semiconductor heterostructure composite with a competent electrolyte membrane for LT-CFCs. The composite comprises CoAl2O4 (CA) in a spine-like structure and wurtzite-structured ZnO. We have demonstrated a button-sized CFC under H2 and ambient air environment delivering a high power density of 835 mW-cm−2 at 550 °C, with potential operating up-to 400 °C. Compared to ZnO and CA alone, the CA-ZnO heterostructure composite has reduced oxygen vacancy production and activation energy, facilitating ion transport more quickly through the CA-Zn interface. Density functional theory (DFT) computations, photoelectron spectroscopy, U-visible, X-ray diffraction, and HR-TEM are the characterization techniques used to study the enhanced ionic conduction of the CA-ZnO heterostructure composite. These results imply that the heterostructure approach works better than the simple bulk structure for the electrolyte application of LT-SOFCs.

RGO modified α-Fe2O3–ZnFe2O4 heterojunction for improving sensing performance of α-Fe2O3 to triethylamine

In order to develop a sensitive, stable and cheap gas sensor for detection of triethylamine (TEA), the bimetal oxide of ZnFe2O4 with α-Fe2O3 heterojunctions with different proportions were synthesized and reduced graphene oxide (rGO) modified on heterojunctions by hydrothermal and chemical precipitation methods. The gas-sensing tests to TEA showed that the 6α-Fe2O3/ZnFe2O4-rGO (0.8 wt%) composite has highest response reaches 10.48–20 ppm TEA with a rapid response time of 29 s, an impressively low detection limit of 0.145 ppm and reliable stability within 32 days at operating temperature of 143 °C. Compared with reported before, it has higher response at lower operating temperature and lower concentration of test gas. The enhancing mechanism is attributed to the formation of semiconductor heterojunction, which makes the resistance of composite in air further increase and further decrease in TEA compared with α-Fe2O3 due to generating an additional electron depletion layer in the heterojunction interface, while rGO accelerates the electron transfer and provides more active sites for gas adsorption.

The SPES Laser Ion Source: Time Structure and Laser Enhancement Measurements with Sm+ beam

A two-step resonance photo-ionization scheme has been used to ionize samarium atoms in the SPES tantalum hot-cavity ion source. The effect of the ion load on the ion beam time structure and the laser enhancement of the ion yield has been studied at different ion source temperatures. Generally, the introduction of more positive ions (ion load) affects negatively the overall confinement of the laser ions inside the volume of the ion source. Possible enhancement of the laser ion confinement through the introduction of neutrals is observed as well. The ion load is also observed to affect the confinement in the transfer line much more than in the hot cavity. Measurement of the time structure with inverted polarity of the cavity DC heating supply confirmed the significance of the longitudinal potential for ion extraction. The laser enhancements of the ion yield are found to be sensitive to the ion load at low operating temperature of the ion source i.e. 1800°C, whereas at 2050°C and 2200°C, they are relatively stable till an ion load value of 1.2 µA.

GaN HEMT and Air Core Magnetics based Power Converters Evaluations at Cryogenic Temperature

Cryogenic power electronics is both advantageous and indispensable in many applications, like deep space probe, military electric vehicle, magnetic resonance imaging etc. Among different semiconductors, the gallium nitride (GaN) high electron mobility transistor (HEMT) is the most promising candidate for cryogenic applications with significant conduction loss and switching loss reductions. Moreover, there is no carrier freeze out effect for the GaN HEMTs, which is applicable in extreme low temperature operating conditions. In this work, the efficiency of GaN HEMTs based power converters with different power levels (from several Watts to several kiloWatts) are evaluated at cryogenic temperature. Three different commercial GaN HEMTs are used in these power converters, including the Texas Instruments LMG5200 80 V GaN half-bridge power stage with integrated gate driver, the GaN Systems 650 V bottomcooled GaN HEMT GS66516B, and the 650 V top-cooled GaN HEMT GS66516T from GaN Systems. Moreover, two different cryogenic power converter evaluation methods (cryogenic chamber and liquid nitrogen channeled through cold plate) are investigated. Three of these power converters are evaluated by using a cryogenic chamber and such that the converter operating environment temperature can be regulated. One of the power converters is evaluated by using liquid nitrogen (LN2) channeled through a cold plate, where the gate driver can be designed to operate at non-cryogenic temperatures to ensure the safe operation of the system. Due to the degraded performance of conventional magnetic components, air core magnetics are used in these power converters to improve the converter efficiency. Efficiency improvements at cryogenic temperature are observed for all the GaN HEMTs and air core magnetics based power converters, which are promising for cryogenic power electronics applications.

Review of cryogenic power conversion and its potential in future all electric transportation systems: from silicon age to WBG era

Cryogenic power electronic conversion (< 123 K) is expected to offer higher efficiencies for future all-electric transportation platforms. Low temperature operation of converters together with integration of wide bandgap devices (WBG) can enable higher switching frequencies with reduced filtering components. This paper briefly reviews the passive components involved in the development of a cryogenic converter. The paper also reviews in detail the converter development with WBG devices by far, and provides a discussion on benefits achieved, and challenges in terms of auxiliary components and measurements. The last part of the paper gives a discussion on envisioned challenges, and different research directions for future superconducting power conversion systems.

Mo-based MXenes as highly selective two-electron oxygen reduction catalysts for H2O2 production

Hydrogen peroxide production through the electrochemical two-electron oxygen reduction presents a compelling alternative to the anthraquinone process due to the cheap starting materials and low operating temperature and pressure. Transition metal species featuring with multi-active sites, offer high electrochemical activity and selectivity. MXenes, distinguished by excellent electrical conductivity and the two-dimensional structure facilitating smooth ion transportation, further enhance the prospects of this production approach. In this study, three Mo-based MXenes were synthesized: Mo2TiC2Fx, Mo2Ti2C3Fx and Mo2CFx. Among these, Mo2TiC2Fx emerged as the most promising catalyst for 2e−ORR, achieving a remarkable H2O2 yield of up to 0.54 mol·gcat−1·h−1. Moreover, it also exhibits a high H2O2 selectivity ranging from 81.3 % at 0.2 V to 94.1 % at 0.6 V vs. RHE, coupled with an impressive faradaic efficiency of 76.4 % at 0.4 V using H-cell. Further analysis indicates that the superior 2e−ORR performance can be attributed to the presence of metallic Mo on the surface of Mo2TiC2Fx.

ПОВЫШЕНИЕ ЭКСПЛУАТАЦИОННЫХ ПОКАЗАТЕЛЕЙ ДИЗЕЛЬНОГО ДВИГАТЕЛЯ ВНУТРЕННЕГО СГОРАНИЯ

The current problem of operating automotive equipment at low temperatures associated with the loss of diesel fuel’s properties (reducing the cloud point and crystallization of the fuel) is being considered, resulting in equipment failures due to failure of the power system and direct freezing of the fuel in the tubes, paraffin deposition leading to clogging of fuel filters. Domestic automotive vehicles do not have any effective means of heating diesel fuel, which forces drivers operating equipment in harsh climatic conditions to use their own individual developments. For these purposes, a device has been developed that allows you to heat all the diesel fuel poured into the fuel tank. The drive of the device (fuel priming pump) is proposed to be electric (from a linear electric motor), from the vehicle's on-board network, the type of pump used is piston, double-acting. A comprehensive calculation of the fuel priming pump is presented in order to determine its main characteristics and design dimensions. A schematic diagram of the installation of the developed device and all elements in the diesel engine power system is presented. The implementation of the proposed technical solution was carried out in the power system of the YaMZ-238 diesel engine installed on a load stand under conditions of its operation in low temperatures (the Far North, etc.). The obtained results of tests on a bench engine confirm the relevance of the research and showed that the use of the developed technical solution will allow heating all the diesel fuel poured into the car tank to a temperature of plus 50 °C, thereby eliminating the possibility of its crystallization and cloudiness and, in general, reducing the number of vehicle failures. techniques related to this problem.

Fabrication of NiO based thin film for high-performance NO2 gas sensors at low concentrations

Recent industrial and technical developments continuously result in the release of dangerous and toxic gases that have adverse effects on human life and the environment. Metal oxide nanomaterials attract attention for extremely sensitive gas sensors owing to their high surface-to-volume ratio, thermal stability, availability, and simplicity of production. Currently, p-type NiO based gas sensors are very promising, due to their outstanding repeatability, high sensitivity, low cost, and environmentally friendly characteristics. In this work, NiO prepared by low-cost hydrothermal method and its gas sensing behavior towards NO2 gas has been studied in detail. The as-prepared structure of NiO has been analyzed by using various characterization techniques like XRD, FESEM, FTIR, BET and UV–visible absorption for the study of structural, morphological and optical properties. The NiO thin film deposited on a glass substrate was analyzed under varying concentrations of NO2 at different working temperatures (100–250 °C). The sensor demonstrated a remarkable sensitivity of 45 % to 10 ppm of NO2 at low operating temperature of 200 °C. Moreover, its consistent repeatability further underscores its reliability, emphasizing its suitability for accurate and dependable NO2 detection in diverse scenarios.

Interface Defects and Carrier Regulation in MOF-Derived Co3O4/In2O3 Composite Materials for Enhanced Selective Detection of HCHO.

Gas sensors for real-time monitoring of low HCHO concentrations have promising applications in the field of health protection and air treatment, and this work reports a novel resistive gas sensor with high sensitivity and selectivity to HCHO. The MOF-derived hollow In2O3 was mixed with ZIF-67(Co) and calcined twice to obtain a hollow Co3O4/In2O3 (hereafter collectively termed MZO-6) composite enriched with oxygen vacancies, and tests such as XPS and EPR proved that the strong interfacial electronic coupling increased the oxygen vacancies. The gas-sensitive test results show that the hollow composite MZO-6 with abundant oxygen vacancies has a higher response value (11,003) to 10 ppm of HCHO and achieves a fast response/recovery time (11/181 s) for HCHO at a lower operating temperature (140 °C). The MZO-6 material significantly enhances the selectivity to HCHO and reduces the interference of common pollutant gases such as ethanol, acetone, and xylene. There is no significant fluctuation of resistance and response values in the 30-day long-term stability test, and the material has good stability. The synergistic effect of the heterostructure and oxygen vacancies altered the formaldehyde adsorption intermediate pathway and reduced the reaction activation energy, enhancing the HCHO responsiveness and selectivity of the MZO-6 material.

Enhanced CO sensor based on In2O3 nanocubes with decoration of Au under high humidity: Experimental combined with theoretical study

Au-modified In2O3 nanocubes with varying Au content (0.7, 1, 2, 3, 10 mol%) were prepared via a simple hydrothermal method and in-situ reduction. The morphology of Au-modified In2O3 was consistent with pure In2O3, both exhibiting cubic structures composed of ∼31 nm particles. Gas sensing tests revealed that compared to pure In2O3, 1 mol% Au-modified In2O3 nanocubes exhibited a 40 °C lower optimal operating temperature (OOT), and a higher response value of 4.88 to 100 ppm CO. Additionally, Au/In2O3 sensors showed significantly less influence from humidity (75 %, 85 %) than pure In2O3 sensors and maintained CO sensing ability under high humidity conditions. First-principles calculations of the adsorption energies of CO molecules on In2O3 and Au/In2O3 surfaces were further performed to investigate the gas sensing mechanism. The results indicated that the improved CO sensing performance of Au/In2O3 sensors can be attributed to the chemical sensitization effects of Au.

Nonaggregated Anions Enable the Undercooled Aqueous Electrolyte for Low-Temperature Applications.

Aqueous batteries, with the advantages of high safety and low cost, are highly promising for large-scale energy storage. However, freezing of the aqueous electrolyte limits the low-temperature operation. Here, we propose and achieve a highly dispersed solvation structure in the electrolyte by coupling nonaggregated Cl- anions, which reduces the water cluster size and prevents the solidification of the aqueous electrolyte until -136.3 °C. The low-temperature LiCl electrolyte exhibits a high ionic conductivity (1.0 mS cm-1) at -80 °C and enables a stable low-temperature Ag/AgCl reference electrode at -50 °C. Moreover, the polyaniline-based battery can work at an extremely low temperature of -100 °C and shows superior cycling performance of 4000 cycles at -40 °C with 95.7% capacity retention. This work elucidates the correlation between the anion effect and the thermodynamic transition of the electrolyte, offering a novel approach for designing low-temperature electrolytes.

Ornated hydrangea-like M-MO/graphitic porous carbon derived via direct carbonization of MOFs for electrooxidation of methanol in alkaline DMFC

Due to their low operating temperature, ease of storage, transportation, and low greenhouse gas emissions, direct methanol fuel cells (DMFC) are considered the best choice of fuel cells for energy conversion. Although its theoretical thermodynamic energy conversion efficiency is ~97 %, its achievable energy conversion efficiency is still in the range of 30–40 %. To improve the reaction kinetics, it is important to look for an electrocatalyst with low cost and high efficiency. In the present study, direct carbonization of [Ni, Cu, and (Ni/Cu)] metal-organic framework (MOF) was carried out under a nitrogen gas flow at 800 °C for 2.5 h, where the MOF precursor was completely converted into graphitic porous carbon well ornamented with Metal/Metal oxides (M/MO). The as-prepared nanomaterials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectric spectroscopy (XPS), Fourier transform infrared (FTIR), and the Brunauer–Emmett–Teller technique (BET). The prepared materials were used as electrocatalysts in a methanol oxidation reaction solution in an alkaline solution. The cyclic voltammetry (CV) measurements for Ni-MOF, Cu-MOF, (Ni/Cu) MOF, Ni-MOF800, Cu-MOF800, and (Ni/Cu)MOF800 showed excellent current densities of 17, 1.05, 44.25, 30, 11.56, and 53 mA∙cm−2, respectively at 0.6 V with a scan rate of 50 mV∙s−1. Whereas, the retention percent value is (96.2 %) for Ni-MOF, (93.1 %) for (Ni/Cu) MOF800, (96.7 %) for (Ni/Cu) MOF, (87.5 %) for Ni-MOF800, (97 %) for Cu-MOF, and (50.2 %) for Cu-MOF800 after an hour. Since M/MO/C800 demonstrated remarkable catalytic activity in relation to methanol oxidation and an abundance of cheap value, it is regarded as a promising candidate for future electrooxidation catalysis of MeOH in direct methanol fuel cells (DMFCs).

Emission current enhancement from quasi-freestanding epitaxial graphene microstructure electron emitters through surface layered silicon dioxide

Enhanced electron emission from oxide-encapsulated quasi-freestanding bilayer epitaxial graphene devices is reported, including one emission current of 9.4 µA and successful emission even with oxide thicknesses of up to 1.25 µm. The low operating temperature (215 °C), and applied electric fields under which the devices operate indicate electron emission is due to phonon-assisted electron emission, wherein forward-scattering hot phonons impart the necessary energy for the electrons to escape the graphene as an emission current. A suite of device structures and behaviors are cataloged, and various emission behaviors are demonstrated through encapsulating oxide layers. Emission current enhancement due to electron multiplication in the oxide layers is observed across multiple devices and oxide thicknesses.

SO2- and H2O-tolerant catalytic reduction of NOx at low temperatures through shielding ceria-based catalyst from poisoning: An efficient protection mechanism

Improving SO2/H2O resistance at low temperatures is a key challenge for industrial applications of NH3-SCR catalysts. Herein, a novel catalyst with remarkable low-temperature NH3-SCR activity and strong SO2/H2O resistance was designed by loading MoOx protective layer over porous kit-CeO2. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) coupled with basic characterization techniques were utilized to further elucidate the underlying mechanisms, and a dynamic balance between the deposition and decomposition of ammonia bisulfate was captured over porous kit-CeO2. Highly dispersed MoOx species pre-adsorbed with NH3 significantly curtailed the adsorption of NOx molecules, and the catalytic reaction over MoOx/kit-CeO2 primarily followed by the Eley-Rideal mechanism. At 250 °C, in the presence of SO2 and H2O, the Ce-O-Mo pairing site was almost unaffected and the super SO2- and H2O-tolerant property originated from the facilitated decomposition of ammonium bisulfate (ABS) and the shielding effect of Mo protective layer on SO2/H2O. This study provided an important guidance to the application of ceria-based catalysts for environmental control within low-temperature operations in non-power industries such as glass, steel, cement manufacturing, etc.

The NaClO4-water eutectic electrolyte for environmentally friendly electrical double-layer capacitors operating at low temperature

Herein, owing to its remarkable ionic conductivity, the 8.84 mol kg−1 NaClO4 water-in-salt (WIS) eutectic electrolyte is suggested for the low temperature operation of electrical double-layer capacitors down to -35 °C. Molecular dynamic simulations reveal that the local structure of the solution remains relatively stable from RT to -35 °C, with distinct channel-like domains formed by hydrogen-bonded water molecules, which facilitate the ionic diffusion within the bulk of the electrolyte. Interestingly, on activated carbon (AC) electrodes, the electrolyte demonstrates an electrochemical stability window (ESW) increasing from 1.8 V to 2.1 V as temperature decreases from 25 °C to -35 °C. The high ESW of this electrolyte is due to i) pH close to neutrality enabling high overpotential of water reduction on porous AC electrodes; ii) WIS characteristics with a reduced amount of free water in the Stern layer under positive polarization of AC; iii) higher oxidation potential at low temperature ascribed to the enhanced immobilization of the ClO4− anions in the Stern layer as well as reduced diffusion of water molecules in the AC electrode porosity. The electrochemical investigations on laminate AC//AC cells in the NaClO4-water electrolyte demonstrate low values of their resistive components down to -30 °C, while the devices can operate with rated voltage of 2.0 V and 1.7 V at -30 °C and RT, respectively. At -30 °C and under discharge power as high as 10 kW kg−1, the AC//AC capacitor in the NaClO4-water electrolyte outperforms the specific output energy of a traditional AC//AC cell in the 1 M TEABF4/ACN electrolyte. Hence, for sub-ambient temperatures, the presented environmentally friendly EDLC holds promise to compete with traditional devices implementing an organic electrolyte.

Magnetic, Optical, Electrical and Antimicrobial Properties of MnCuZnFe2O4 Nanoparticles

AbstractThe Mn0.92Cu0.08‐yZnyFe2O4 (y=0.02, 0.04, 0.06 and 0.08) nanoparticles (MCZF NPs) were synthesized via the hydrothermal process at low operating temperature. The MCZF system generated a cubic spinel structure as seen by the X‐ray diffraction patterns. The average crystallite size was observed to be increasing from 25 to 30 nm. The broad (γ1) and narrow (γ2) absorption bands were seen in FTIR spectra and the cation distributions at tetrahedral (A) and octahedral (B) sites, respectively, was indicated. The surface morphology was analyzed using electron microscopy. Clarification was provided for the dependence of the optical bandgap shift (Eg~1.96–2.15 eV) on the concentration of substituent. The superparamagnetic nature of MCZF can be advantageous for biomedical applications and it was demonstrated by the magnetization versus applied magnetic field (M−H) loops. Small values of remanence magnetization (Mr) and coercivity (Hc) were found using magnetization versus magnetic field (M−H) curves at y=0.02, 0.04, 0.06, and 0.08. This proved that MCZF NPs exhibited the superparamagnetic behavior. The cation distribution at two sublattices was also estimated using a two‐sublattice model. The greatest zone of inhibition in an antibacterial study of MCZF (produced by the green method) was 10.8 mm for Pseudomonosa aeruginosa and 9.4 mm for Staphylococcus aureus.