High Loading Amount Research Articles

Precise Construction of Stable Bimetallic Metal–Organic Frameworks with Single-Site Ti(IV) Incorporation in Nodes for Efficient Photocatalytic Oxygen Evolution

Precise Construction of Stable Bimetallic Metal–Organic Frameworks with Single-Site Ti(IV) Incorporation in Nodes for Efficient Photocatalytic Oxygen Evolution

Atomically Dispersed Ruthenium on Nickel Hydroxide Ultrathin Nanoribbons for Highly Efficient Hydrogen Evolution Reaction in Alkaline Media.

Achieving highly efficient hydrogen evolution reaction (HER) in alkaline media is a great challenge. Single-atom catalysts with high-loading amount have attracted great interest due to their remarkable catalytic properties. Herein, by using nickel foam as the substrate, the authors design and precisely synthesize atomic ruthenium (Ru)-loaded nickel hydroxide ultrathin nanoribbons (R-NiRu) with a high atomic Ru loading amount reaching ≈7.7wt% via a one-step hydrothermal method. The presence of concentrated Cl- in the synthetic system is beneficial for constructing ultrathin nanoribbons, which, with abundant edge OH groups, make it easy to trap atomic Ru. Taking advantage of the synergy between atomic Ru and the nanoribbon morphology of nickel hydroxide, R-NiRu exhibit a low overpotential of 16mV for HER at 10mAcm-2 and a Tafel slope of 40mVdec-1 in aqueous 1.0mKOH solution, which are superior to those of commercial Pt/C (overpotential of 17mV at 10mAcm-2 , Tafel slope of 43mVdec-1 ). Density functional theory (DFT) calculation results demonstrate that atomically dispersed Ru can significantly reduce the HER energy barrier. Moreover, R-NiRu maintains exceptional stability after 5000 cyclic voltammetry cycles. This efficient and facile synthetic strategy provides a new avenue for designing efficient catalysts.

Black Phosphorus Nanosheet Encapsulated by Zeolitic Imidazole Framework-8 for Tumor Multimodal Treatments.

Black phosphorus (BP) nanosheet is easily oxidized by oxygen and water under ambient environment, thus, reliable BP passivation techniques for biomedical applications is urgently needed. A simple and applicable passivation strategy for biomedical applications was established by encapsulating BP nanosheet into zeolitic imidazole framework-8 (ZIF-8). The resulted BP nanosheet in ZIF-8 (BP@ZIF-8) shows not only satisfied chemical stability in both water and phosphate buffered saline (PBS), but also excellent biocompatibility. Notably, BP nanosheet endows the prepared BP@ZIF-8 with prominent photothermal conversion efficiency (31.90%). Besides passivation BP, ZIF-8 provides the BP@ZIF-8 with high drug loading amount (1353.3 mg g-1). Moreover, the loaded drug can be controlled release by pH stimuli. Both in vitro and in vivo researches verified the resulted BP@ZIF-8 an ideal candidate for tumor multimodal treatments.

Low-Temperature Hydrogenation of Toluene Using an Iron-Promoted Molybdenum Carbide Catalyst

As an alternative to noble metal hydrogenation catalysts, pure molybdenum carbide displays unsatisfactory catalytic activity for arene hydrogenation. Precious metals such as palladium, platinum, and gold are widely used as additives to enhance the catalytic activities of molybdenum carbide, which severely limits its potential applications in industry. In this paper, iron-promoted molybdenum carbide was prepared and characterized by various techniques, including in situ XRD, synchrotron-based XPS and TEM. while the influence of Fe addition on catalytic performance for toluene hydrogenation was also studied. The experimental data disclose that a small amount of Fe doping strongly enhances catalytic stability in toluene hydrogenation, but the catalytic performance drops rapidly with higher loading amounts of Fe.

PVP-stabilized platinum nanoparticles supported on modified silica spheres as efficient catalysts for hydrogen generation from hydrolysis of ammonia borane

Ammonia borane (AB) is considered to be a promising solid hydrogen carrier. In this work, poly(N-vinyl-2-pyrrolidone) (PVP)-protected platinum nanoparticles are supported on γ-methacryloxypropyltrimethoxysilane (γ-MPS) modified silica spheres (Pt-PVP/SiO2(M)), which are firstly used as highly efficient catalysts for hydrolysis of AB. Platinum nanoparticles possess a tiny size of 2–3 nm and are uniformly dispersed over modified silica spheres. Pt-PVP/SiO2(M) catalysts with a Pt loading amount of 1.30 wt% show the highest catalytic activity with a turnover frequency (TOF) value of 371 molH2 molPt−1 min−1 (866 molH2 molPt−1 min−1 corrected for the surface atoms) at 25 °C. The activation energy is calculated to be 46.2 kJ/mol. Furthermore, owing to the synergistic effect between the modifier of silica spheres and the capping agent of metal nanoparticles, Pt-PVP/SiO2(M) catalysts have a higher loading amount (8.7 and 6.5 times) and TOF value (4.8 and 5.5 times) than the counterparts prepared without γ-MPS and PVP, respectively.

Interfacial Design of Mixed Matrix Membranes via Grafting PVA on UiO-66-NH2 to Enhance the Gas Separation Performance.

In this study, defect-free facilitated transport mixed matrix membrane (MMM) with high loading amount of UiO-66-NH2 nanoparticles as metal–organic frameworks (MOFs) was fabricated. The MOFs were covalently bonded with poly (vinyl alcohol) (PVA) to incorporate into a poly (vinyl amine) (PVAm) matrix solution. A uniform UiO-66-NH2 dispersion up to 55 wt.% was observed without precipitation and agglomeration after one month. This can be attributed to the high covalent interaction at interfaces of UiO-66-NH2 and PVAm, which was provided by PVA as a functionalized organic linker. The CO2 permeability and CO2/N2 and selectivity were significantly enhanced for the fabricated MMM by using optimal fabrication parameters. This improvement in gas performance is due to the strong impact of solubility and decreasing diffusion in obtained dense membrane to promote CO2 transport with a bicarbonate reversible reaction. Therefore, the highest amount of amine functional groups of PVAm among all polymers, plus the abundant amount of amines from UiO-66-NH2, facilitated the preferential CO2 permeation through the bicarbonate reversible reaction between CO2 and –NH2 in humidified conditions. XRD and FTIR were employed to study the MMM chemical structure and polymers–MOF particle interactions. Cross-sectional and surface morphology of the MMM was observed by SEM-EDX and 3D optical profilometer to detect the dispersion of MOFs into the polymer matrix and explore their interfacial morphology. This approach can be extended for a variety of polymer–filler interfacial designs for gas separation applications.

Free-Standing N-Doped Carbon Cathode for Li-S Battery

A free-standing carbon cathode is attractive in that it can increase the proportion of active material without any current collector, conductive material, and binder. This study introduces a free-standing carbon cathode derived from CO2 with very high porosity for lithium-sulfur battery. The free-standing carbon cathode, while having its very porous structure, shows very excellent elasticity, providing potential as a standalone electrode material in industry. In addition, in the process of making free-standing carbon through electrospinning of polyacrylonitrile (PAN) and NaBH4, the very rich N atoms, 19.38wt% of pyridinic N and 16.24% of pyrrolic-N, exist on the surface, which greatly improves the lithium sulfide adsorption ability and electrical conductivity. As a result, a capacity of 700 mAh g−1 is exhibited for 500 cycles at 0.2 C and 650 mAh g−1 is secured at 5C. Even with a very high active material loading amount of 6.11 mg cm−2, it maintained an areal capacity of 3.1 mAh cm−2 for 500 cycles at 0.2 C with the original free-standing form maintained.

Covalent organic frameworks with immobilized anions to liberate lithium ions: Quasi-solid electrolytes with enhanced rate capabilities

Ionic liquids (ILs) are promising candidates as fast Li+ conductors owing to their high ionic conductivity and admirable stability. However, the mobile ions in ILs will contribute to the overall ion conductivity which decreases Li ions transfer efficiency and rate capability of batteries. The improvemnt of Li ions transfer efficiency in ILs electrolyte materials is a great challenge. Covalent organic frameworks (COFs) with high porosity and aligned nanosize channels can offer free flowing pathways for Li+ migration as well as abundant active sites to anchor anions and liberate free Li+, which can maximize Li+ transfer efficiency. Herein we design a cationic COF and a neutral COF as porous hosts for immobilizing the anions of IL N,N-diethyl-N-(2-methoxyethyl)-N-methylammoniumbis(trifluoromethylsulphonyl)imide (DEME-TFSI) to enhance Li+ transference efficiency. The obtained quasi-solid COFs-IL electrolytes exhibit high IL loading amount owing to strong interactions between COFs and the IL. Moreover, COFs-IL electrolytes show good electrochemical stability and high ionic conductivity over 1×10−3 S cm−1, along with a 90% increase of Li+ transfer number in comparison to the bare IL electrolyte (IL/LiTFSI). Our research provides a general strategy for immobilizing mobile anions to liberate Li+ and improve Li+ transfer efficiency in IL-based electrolytes.

Self-Encapsulation of Biomacromolecule Drugs in Porous Microscaffolds with Aqueous Two-Phase Systems.

At present, the most commonly used methods of microencapsulation of protein drugs such as spray drying, multiple emulsification, and phase separation, can easily cause the problem of protein instability, which leads to low bioavailability and uncontrolled release of protein drugs. Herein, a novel method to encapsulate protein drugs into porous microscaffolds effectively and stably was described. Ammonium hydrogen carbonate (NH4HCO3) was employed to prepare porous microscaffolds. α-Amylase was encapsulated into the porous microscaffolds without denaturing conditions by an aqueous two-phase system (PEG/Sulfate). The pores were closed by heating above the glass transition temperature to achieve a sustained release of microscaffolds. The pore-closed microscaffolds were characterized and released in vitro. The integrity and activity of protein drugs were investigated to verify that this method was friendly to protein drugs. Results showed that the pores were successfully closed and a high loading amount of 9.67 ± 6.28% (w/w) was achieved. The pore-closed microscaffolds released more than two weeks without initial burst, and a high relative activity (92% compared with native one) of protein demonstrated the feasibility of this method for protein drug encapsulation and delivery.

Pulsed Laser Confinement of Single Atomic Catalysts on Carbon Nanotube Matrix for Enhanced Oxygen Evolution Reaction.

The design of atomically dispersed single atom catalysts (SACs) must consider high metal-atom loading amount, effective confinement, and strong interactions with matrix, which can maximize their catalytic performance. Here reported is a promising method to synthesize SACs on highly conductive multiwall carbon nanotube (MWCNT) supports using pulsed laser confinement (PLC) process in liquid. Atomic cobalt (Co) and phosphorus (P) with a high loading density are homogeneously incorporated on the outer wall of the MWCNT (Co-P SAC MWCNT). Density functional theory (DFT) calculations in combination with systematic control experiments found that the incorporated Co and P adatoms act as an adsorption energy optimizer and a charge transfer promoter, respectively. Hence, favorable kinetics and thermodynamics in Co-P SAC MWCNT can be simultaneously achieved for water oxidation resulting in a superior catalytic performance than the benchmark RuO2 catalyst. Crucially, total processing time for assembling Co-P SAC MWCNT via PLC process is less than 60 min, shedding light on the promising practical applications of our SAC design strategy.

Design and characterization of starch/solid lipids hybrid microcapsules and their thermal stability with menthol

A hybrid microcapsule with modified starch shell and solid lipids core was designed to enhance the thermal stability of menthol with high loading. The hybrid microcapsule was prepared by high-pressure homogenization of the lipid and water phase, and spray drying of the modified starch stabilized emulsion. Menthol was incorporated with the oil phase into the modified starch shell. The crystalline structure of menthol in solid lipids and the hybrid microcapsules was investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. The encapsulation efficiency, surface menthol content, loading amount, and thermal stability were optimized. A hybrid microcapsule with a high encapsulation efficiency (99.78%), low surface oil content (3.02%), high loading amount (31.18%) and superb thermal stability was obtained. The microstructure of the hybrid microcapsule was studied by scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). The mechanism of superb thermal stability and high loading was discussed, both of the amorphous form of menthol and the dense modified starch shell are important. Finally, the shelf storage stability for 300 days was evaluated. In general, a simple and general method was provided to stabilize menthol at high temperatures. And the microencapsulation concept proposed in this manuscript may provide a potential idea for other crystalline active ingredients used in food, cosmetic and pharmaceutical area.

Fabrication of whey protein isolate-sodium alginate nanocomplex for curcumin solubilization and stabilization in a model fat-free beverage

The present study aimed to fabricate whey protein isolate (WPI)-sodium alginate (ALG) nanocomplexes for curcumin (CUR) stabilization in a model fat-free beverage. Mass ratio of 5:1 at pH 5.0 in the absence of NaCl was optimized for WPI-ALG nanocomplex fabrication. Mean particle size and zeta-potential of CUR-WPI-ALG nanocomplex was 209.9 nm and −39.1 mV at pH 5.0, respectively. Highest loading amount (LA) of CUR in CUR-WPI-ALG nanocomplex were 15.26 μg/mg. No obvious precipitates were observed for CUR-WPI-ALG nanocomplex under simulated food processing and storage conditions including high sucrose, high NaCl, and thermal treatment at 90 °C for 2 h. Fluorescence results confirmed that the spontaneous interaction between CUR and WPI-ALG nanocomplex was primarily motivated by hydrophobic interaction and hydrogen bonding. Compared with CUR (free), chemical stability (UV light, and heat), and DPPH scavenging capacities of CUR in CUR-WPI-ALG nanocomplex were strikingly improved.

300Wh/Kg Class High-Energy Li-S Laminated Batteries Using High-Sulfur Loading Cathode on 3D Mesh Structured Aluminum Foam

[Introduction] In recent years, lithium-sulfur batteries can be expected as a promising candidate for next generation energy storage devices because of its high energy density. Generally, the cathode is fabricated by infiltration of sulfur into Ketjen black (KB) with aluminum foil current collector. However, it is not easy to increase the sulfur loading amounts and maintain the rate performances for electric vehicles which are required more than 3C rate, due to the lack of Li ion and electron paths. To solve this issue, we have reported the new type sulfur electrode prepared using 3D mesh structured Al foam, resulting in increased sulfur loading amounts which are 5 - 10 times or more compared to conventional sulfur cathode fabricated using 2D structured aluminum foil current collector [1], [2], [3]. In this study, we optimized the fabrication method of sulfur cathode for high sulfur loading on 3D mesh structured Al foam for a high energy density Li-S laminated battery.[Experimental] S/KB composite was obtained by mixing sulfur and KB with weight ratio of 6:4, by heating at 155 °C for 12 h under N2 atmosphere. Afterward obtained S/KB composite was dispersed by ball milling for 12h. S/KB cathode was fabricated by S/KB slurry (weight ratio of S/KB (6/4) : Binder = 96.5 : 3.5). The high sulfur loaded cathode (15.3 mg/cm2) was obtained using 3D mesh structured Al foam (1mm in thickness). To assemble the cell, the cathode was pressed (0.4 mm in thickness). 5 Ah class laminated cell (70 x 70 mm) was prepared using the S/KB cathodes (6 stacked), Li anodes (7 stacked), separators (7 stacked), and the electrolyte (LiTFSI: G1(monoglyme)/G3(triglyme): HFE(hydrofluoroether)= 1: 1: 4 (molar ratio)). Electrochemical performances were tested with voltage range between 1.0 V – 3.3 V after activation process.In addition, coin cells were prepared using above materials to evaluate the ionic conductivity by DC polarization method.[Results and Discussion] To design a high energy density cell such as laminated type cell, it is important to optimize the ratio between using amount of electrolyte and solid materials in electrode. Fig. 1 shows the relationship between the calculated E/S ratio (electrolyte amount (µℓ)/sulfur loading amounts (mg)), porosity filling rate of electrolyte (%), and the gravimetric energy density (Wh/kg). It was possible to reduce the electrolyte filling rate to 100% which is corresponding to E/S = 1.7, achieving the 340 Wh/kg theoretically. It is important to secure an ion path in whole electrode to optimize utilization of E/S ratio. In our previous report, we fabricated the S/KB cathode using 3D mesh structured Al foam regardless of the porosity, implying that it has bad ion conductivity. To improve the ion conductivity of S/KB cathode which has high sulfur loading amounts, we prepared a cathode that loaded S/KB very uniformly and retained the high porosity of the 3D mesh structured Al foam.As a result, we confirmed that the S/KB cathode/3D Al mesh which has good porosity shows improved ionic conductivity than control sample fabricated by conventional method.Fig. 2 shows the charge/discharge curve of Li-S laminated battery prepared by a new method with optimized E/S ratio of 2.3 (conventional method requires high E/S ratio of 3.6 or more). High capacity of 5.2 Ah, and energy density (301 Wh/kg and 435 Wh/ℓ, excluding laminate and tab) was achieved with high sulfur loaded laminated cell (sulfur loading amount of 15.4 mg/cm2, 1156 mAh/g-S).

Bimetallic MOFs(Co/Mn)@Rice Husks for Electrode Materials

Novel pseudocapacitive nanomaterials storing energy electrochemically through surface redox reactions have been extensively investigated as an electrode to increase both power and energy density. The pyrolysis of metal-organic frameworks (MOFs), assembled from metal ions and organic ligands, generates well dispersed metal oxides within the carbon with high surface area. Herein, we report the synthesis of CoMn2O4/Co/MnO @rice husks (RHs) by pyrolysis of two different-sized bimetallic Co/Mn-MOFs@RHs and their electrochemical performance. SEM and PXRD analysis showed that Mn(CH3CO2)2/Co(NO3)2-derived MOF-74 (1) has much smaller crystal size and grain size than those of MnCl2/Co(NO3)2-derived MOF-74 (2) although both have an identical phase. The different crystal sizes of 1 and 2 were rationalized by considering the nucleophilic reactivity of the counter anions to the metal cations. For instance, acetate during the crystallization of 1 has a higher nucleophilic reactivity than chloride during that of 2 in DMF, hence acetate is less readily solvated. Consequently, the smaller crystal size of 1 means a higher loading capacity inside the channels of the RHs compared to 2 since the larger crystal size of 2 can block the channels of the RHs and lead to lower loading capacities. The pyrolysis of 1@RH and 2@RH generates CoMn2O4/Co/MnO mixtures inside the RHs, which work as pseudocapacitive nanomaterials. Interestingly, the electrochemical performance of 1_C@RHs is superior to that of 2_C@RHs even though they have a similar surface area. The high capacitance of 1_C@RHs across all scan rates is attributed to the high loading amount of metal/metal oxide in RHs, high mesopore volume and good electrical contact. Furthermore, the smaller crystals size of 1 than that of 2 prevents the blockage of micrometer-scale channels of RHs, and increases the loading amount of 1 and the mesopore volume. Therefore, the crystal size control of MOFs in RHs is crucial to improve the electrochemical performance of pseudocapacitive nanomaterials. We believe that the impregnation of well-organized MOFs in biomass carbons could contribute the design of novel energy storage devices with high performance.

A low temperature catalytic-type combustible gas sensor based on Pt supported zeolite catalyst films

In this study, a catalytic-type combustible gas sensor was fabricated by the screen-printing method. Pt supported catalysts (Pt-HZSM5) were prepared by a wet impregnation method using HZSM5 zeolite as support. It was found that Pt-HZSM5 catalysts have a highly catalytic activity to H2 and CO at low temperatures and a selectively and fully combustible was observed at only 150 °C. A good dispersion state of Pt nanoparticles on HZSM5 zeolite particles was beneficial for the catalytic oxidization of CO and H2. However, a high loading amounts lead to a poor dispersion state and a weak catalytic activity. The thick film sensor based on Pt-HZSM5 catalyst was found to be highly sensitive to combustible gas with a good linearity up to 2% and a limitation of detection (LOD) around 50 ppm. Due to the low operation temperature, a highly selectivity was obtained for CO and H2 and no cross-sensitivity to interfering gases such as CH4 and VOCs. It was indicated that the present developed catalytic-type gas sensors could be used for the leakage detection and monitor for H2 and CO with a low power consumption and a good selectivity.

Potential Antioxidant and Wound Healing Effect of Nano-Liposol with High Loading Amount of Astaxanthin.

BackgroundAstaxanthin (ASTA), a carotenoid, is a strong antioxidant. However, its application in functional foods, pharmaceuticals, and cosmetics remains limited due to its low aqueous solubility and stability. Several different encapsulating materials have been used to improve the stability and bioavailability of ASTA; however, the currently investigated nano-carriers for ASTA require additional improvements with regard to their loading capacity and stability.MethodsIn this study, we developed lecithin nano-liposol (Lec NS) as a novel carrier of ASTA using a simple emulsion evaporation method. The physicochemical characteristics including hydrodynamic diameter, polydispersity index, surface charge and morphology were analyzed by DLS and TEM. The antioxidant activity of the ASTA-loaded Lec NS (ASTA@Lec NS) was evaluated using a DPPH radical scavenging assay and in vitro antioxidant assay. The study of in vitro wound healing efficacy was carried out to observe the beneficial effect of antioxidant activity of ASTA@Lec NS on cell migration.ResultsASTA@Lec NS showed improved stability and efficacy owing to improved aqueous solubility of ASTA inside Lec NS. Both in situ and in vitro antioxidant activities of ASTA@Lec NS were higher than that of bare ASTA and Lec NS. It also exhibited strong wound healing efficacy by regulation of ROS level in in vitro cell model.ConclusionThis study revealed that the encapsulation of ASTA into Lec NS using a wet phase transfer enhanced its physiological stability and bioavailability for effective scavenging of reactive oxygen species.

An applied quantum-chemical model for genipin-crosslinked chitosan (GCS) nanocarrier

The genipin-crosslinked chitosan (GCS) nanocarrier has received a lot of attention due to its unique biological and chemical properties as an effective drug delivery system. GCS was modeled by considering two chitosan (CS) polymer sequences with six monomer units that are crosslinked by genipin. To investigate the characteristics of this model, we considered it as a nanocarrier of the anti-cancer drug cladribine (2CdA). Seven configurations of GCS and 2CdA (GCS/2CdA1-7) were optimized at M06-2X/6-31G(d,p) in aqueous solution. The average binding energy above 100 kJ mol−1 indicates a high drug loading amount. The high adsorption of the drug on GCS is due to the hydrogen bonds that were investigated by AIM analysis. Hydrogen bonds also allow the drug to be released more slowly. These results were confirmed by experimental evidence and the comparison of this model with the simple model of one polymer chain. Also, the mechanism of GCS formation was investigated by calculating the activation parameters, which indicates that solvent (H2O) molecules are explicitly involved in the formation of GCS.

The properties of MOF-Zn2(EBNB)2(BPY)2\xb72H2O and its basic study of loading methadone

The ligands of (E)-bis(p-3-nitrobenzoic acid) vinyl (C16H10N2O8) were synthesized in three steps, and then the MOF-Zn2(EBNB)2(BPY)2·2H2O was synthesized by solvothermal method. This structure was characterized by X-ray single crystal diffraction, SEM and TG. The drug loading and in vitro release of Zn2(EBNB)2(BPY)2·2H2O were also studied with Methadone as model drug. The results show that the highest loading amount of Zn2(EBNB)2(BPY)2·2H2O to Methadone was 0.256 g/g, and the drug delivery system was a two-phase mode. The results of in vitro cytotoxicity test show that Zn2(EBNB)2(BPY)2·2H2O has good biocompatibility.

In situ synthesis of Co3O4 nanoparticles confined in 3D nitrogen-doped porous carbon as an efficient bifunctional oxygen electrocatalyst

The rational exploitation of non-precious metal catalyst with high activity, strong durability and low cost for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of vital importance for metal–air batteries. Herein, a composite of Co3O4 nanoparticles confined in three-dimensional (3D) N-doped porous carbon (Co-NpCs) was prepared by a simple freeze-drying and in situ pyrolysis method. The effect of different dosages of Co(NO3)2 on the catalytic performance was discussed. The Co-NpC-12% exhibits the best catalytic performance (E1/2 = 0.78 V, better stability than 20% Pt/C) in ORR and in OER among all the as-synthesized samples. Furthermore, it also exhibits the best bifunctional activity (ΔE = 0.849 V). The excellent properties of Co-NpCs are mainly due to the synergy between Co3O4 and carbon. Firstly, a high Co3O4 loading amount can boost the defect level of the N-doped hierarchical porous carbon and expose more active sites. Secondly, the unique in situ pyrolysis guarantees a large-area contact between Co3O4 and carbon as well as a strong C–O–Co bonding, which promotes charge transfer, avoids the peeling of Co3O4 nanoparticles and effectively improves the stability of the material. This work is expected to offer a feasible strategy to produce metal oxide/carbon nanocomposite and push forward the development of bifunctional electrocatalyst with high activity and stability.

Synergistic optimization of Liquid Chromatography and Mass Spectrometry parameters on Orbitrap Tribrid mass spectrometer for high efficient data-dependent proteomics.

Steady improvement in Orbitrap-based mass spectrometry (MS) technologies has greatly advanced the peptide sequencing speed and depth. In-depth analysis of the performance of state-of-the-art MS and optimization of key parameters can improve sequencing efficiency. In this study, we first systematically compared the performance of two popular data-dependent acquisition approaches, with Orbitrap as the first-stage (MS1) mass analyzer and the same Orbitrap (high-high approach) or ion trap (high-low approach) as the second-stage (MS2) mass analyzer, on the Orbitrap Fusion mass spectrometer. High-high approach outperformed high-low approach in terms of better saturation of the scan cycle and higher MS2 identification rate. However, regardless of the acquisition method, there are still more than 60% of peptide features untargeted for MS2 scan. We then systematically optimized the MS parameters using the high-high approach. Increasing the isolation window in the high-high approach could facilitate faster scan speed, but decreased MS2 identification rate. On the contrary, increasing the injection time of MS2 scan could increase identification rate but decrease scan speed and the number of identified MS2 spectra. Dynamic exclusion time should be set properly according to the chromatography peak width. Furthermore, we found that the Orbitrap analyzer, rather than the analytical column, was easily saturated with higher loading amount, thus limited the dynamic range of MS1-based quantification. By using optimized parameters, 10 000 proteins and 110 000 unique peptides were identified by using 20 h of effective liquid chromatography (LC) gradient time. The study therefore illustrated the importance of synchronizing LC-MS precursor ion targeting, fragment ion detection, and chromatographic separation for high efficient data-dependent proteomics.