Experimental and theoretical insights to demonstrate the hydrogen evolution activity of layered platinum dichalcogenides electrocatalysts

Abstract Hydrogen is a highly efficient and clean renewable energy source and water splitting through electrocatalytic hydrogen evolution is a most promising approach for hydrogen generation. Layered transition metal dichalcogenides-based nano-structures have recently attracted significant interest as robust and durable catalysts for hydrogen evolution. We systematically investigated the platinum (Pt) based dichalcogenides (PtS2, PtSe2 and PtTe2) as highly energetic and robust hydrogen evolution electrocatalysts. PtTe2 catalyst unveiled the rapid hydrogen evolution process with the low overpotentials of 75 and 92 mV (vs. RHE) at a current density of 10 mA cm−2, and the small Tafel slopes of 64 and 59 mV/dec in acidic and alkaline medium, respectively. The fabricated PtTe2 electrocatalyst explored a better catalytic activity than PtS2 and PtSe2. The density functional theory estimations explored that the observed small Gibbs free energy for H-adsorption of PtTe2 was given the prominent role to achieve the superior electrocatalytic and excellent stability activity towards hydrogen evolution due to a smaller bandgap and the metallic nature. We believe that this work will offer a key path to use Pt based dichalcogenides for hydrogen evolution electrocatalysts

Metal-organic framework-based nanomaterials for CO2 storage: A review

The increasing recognition of the impact of CO2 emissions as a global concern, directly linked to the rise in global temperature, has raised significant attention. Carbon capture and storage, particularly in association with adsorbents, has occurred as a pivotal approach to address this pressing issue. Large surface area, high porosity, and abundant adsorption sites make metal-organic frameworks (MOFs) promising contenders for CO2 uptake. This review commences by discussing recent advancements in MOFs with diverse adsorption sites, encompassing open metal sites and Lewis basic centers. Next, diverse strategies aimed at enhancing CO2 adsorption capabilities are presented, including pore size manipulation, post-synthetic modifications, and composite formation. Finally, the extant challenges and anticipated prospects pertaining to the development of MOF-based nanomaterials for CO2 storage are described

A HEMATOBIOCHEMICAL EVALUATION TO COMPARE THE EFFECTS OF HIGH INTENSITY INTERVAL TRAINING AND AEROBIC EXERCISE TO CONTROL DIABETES MALLITIS AND ITS COMPLICATIONS

Background: Diabetes has become a very common disease all over the world since last few decades and is now perceived as a global health disorder. Diabetes mellitus is identified on the basis of constant high concentration of blood glucose level and it mainly occurs due to deficiency of the pancreatic hormone insulin. High-intensity interval training (HIIT) is an improved form of interval trainings, and exercise strategies which alternate the periods of small intense anaerobic exercise by less-intense regaining periods. The study aimed to compare the hematological parameters associated with diabetes and muscle activity between healthy humans and diabetic type-1 patients when subjected to HIIT and regular aerobic exercises. Methods: A convenience sample of total 60 participants was taken it comprised of thirty healthy individuals taken from the department of Physical Therapy, University of Sargodha, Lahore campus and thirty diabetic type-1 individuals of age 15-30 years taken from Akhuwat health services clinic Township, Lahore. Participants were divided into four groups of fifteen individuals each. Group one was the diabetic HIIT (DH) group with diabetic type-1 patients subjected to HIIT. Group two was the diabetic aerobic (DA) group with diabetic type-1 patients subjected to regular aerobic exercises. Group three was control High intensity interval training (HH) that consisted of fifteen healthy individuals to be subjected to High intensity interval training exercises (HIIT). Group four (HA) was the control aerobic group with fifteen healthy individuals of average lifestyles subjected to regular aerobic exercises. Results: Aerobic exercise was found to be more effective in reducing glucose level, lowering exogenous insulin and glycated hemoglobin, however HIIT proved to be more effective in lowering blood cholesterol level and decrease LDL level and increase HDL level. Conclusion: It was concluded that aerobic exercise program in comparison to high intensity interval training showed better results in lowering blood glucose levels and HbA1c levels. So we may suggest aerobic exercise program along with drugs as a synergic therapy to control diabetes and its complications

Fabrication of larger surface area of ZIF8@ZIF67 reverse core-shell nanostructures for energy storage applications

Abstract: The construction of uniform nanostructure with larger surface area electrodes is a huge challenge for the highvalue added energy storage application. Herein, we demonstrates ZIF67@ZIF8 (core-shell) and ZIF8@ZIF67 (reverse core-shell) nanostructures using a low-cost wet chemical route and used them as supercapacitors. Pristine ZIF-67 and ZIF-8 was used as reference electrodes. Benefiting from the synergistic effect between the ZIF8 and ZIF67, the ZIF8@ZIF67 exhibited the outstanding electrochemical consequences owing to its larger surface area with uniform hexagonal morphology. As optimized ZIF8@ZIF67 nanostructure displayed the highcapacity of 1521 F/g at 1 A/g of current density in a three-electrode assembly in 1 M KOH electrolyte compared with other as-fabricated electrodes. In addition, the ZIF8@ZIF67 nanostructure employed into the symmetric supercapacitors (SSCs) with 1 M KOH electrolyte in two-electrode setup and it exhibited still superior output including capacity (249.8 F/g at 1 A/g), remarkable repeatability (87 % over 10,000 GCD cycles) along with high energy and power density (61.2 Wh/kg & 1260 W/kg). The present study uncovers the relationship between the larger surface area and electrocatalyst performance, supporting an effective approach to prepare favorable materials for enhanced capacity, extended lifespan, and energy density

A Facile Design of Solution-Phase Based VS2 Multifunctional Electrode for Green Energy Harvesting and Storage

This work reports the fabrication of vanadium sulfide (VS2) microflower via one-step solvo-/hydro-thermal process. The impact of ethylene glycol on the VS2 morphology and crystal structure as well as the ensuing influences on electrocatalytic hydrogen evolution reaction (HER) and supercapacitor performance are explored and compared with those of the VS2 obtained from the standard pure-aqueous and pure-ethylene glycol solvents. The optimized VS2 obtained from the ethylene glycol and water mixed solvents exhibits a highly ordered unique assembly of petals resulting a highly open microflower structure. The electrode based on the optimized VS2 and exhibits a promising HER electrocatalysis in 0.5 M H2SO4 and 1 M KOH electrolytes, attaining a low overpotential of 161 and 197 mV, respectively, at 10 mA.cm−2 with a small Tafel slope 83 and 139 mVdec−1. In addition, the optimized VS2 based electrode exhibits an excellent electrochemical durability over 13 h. Furthermore, the superior VS2 electrode based symmetric supercapacitor delivers a specific capacitance of 139 Fg−1 at a discharging current density of 0.7 Ag−1 and exhibits an enhanced energy density of 15.63 Whkg−1 at a power density 0.304 kWkg−1. Notably, the device exhibits the capacity retention of 86.8% after 7000 charge/discharge cycles, demonstrating a high stability of the VS2 electrode

One-Pot Synthesis of W2C/WS2 Hybrid Nanostructures for Improved Hydrogen Evolution Reactions and Supercapacitors

Tungsten sulfide (WS2) and tungsten carbide (W2C) are materialized as the auspicious candidates for various electrochemical applications, owing to their plentiful active edge sites and better conductivity. In this work, the integration of W2C and WS2 was performed by using a simple chemical reaction to form W2C/WS2 hybrid as a proficient electrode for hydrogen evolution and supercapacitors. For the first time, a W2C/WS2 hybrid was engaged as a supercapacitor electrode and explored an incredible specific capacitance of ~1018 F g−1 at 1 A g−1 with the outstanding robustness. Furthermore, the constructed symmetric supercapacitor using W2C/WS2 possessed an energy density of 45.5 Wh kg−1 at 0.5 kW kg−1 power density. For hydrogen evolution, the W2C/WS2 hybrid produced the low overpotentials of 133 and 105 mV at 10 mA cm−2 with the small Tafel slopes of 70 and 84 mV dec−1 in acidic and alkaline media, respectively, proving their outstanding interfaced electrocatalytic characteristics. The engineered W2C/WS2-based electrode offered the high-performance for electrochemical energy applications

1D-CoSe2 nanoarray: a designed structure for efficient hydrogen evolution and symmetric supercapacitor characteristics

Direct growth of self-supported one-dimensional (1D) nanorod arrays on conducting substrates is highly attractive for electrocatalysis, due to their unique shape, size, and length. In this work, a facile and simple two-step method was employed to synthesize 1D-CoSe2 nanoarrays on titanium (Ti) foil via a wet chemical ion-exchange approach. The as-synthesized 1D-CoSe2 nanoarrays were directly used as electrode materials for hydrogen evolution reaction and supercapacitors. As an electrocatalyst, the optimized 1D-CoSe2(t(ex)-48 h) nanoarray exhibits excellent hydrogen evolution properties with a small Tafel slope of 78 mV dec(-1), low overpotentials of 41 mV@1 mA cm(-2) and 216 mV@10 mA cm(-2), and extended robust performance for 25 h. Moreover, for a symmetric device, it delivers a maximum specific capacitance of 152 F g(-1) at 0.5 A g(-1) and a better energy density of 21.1 W h kg(-1) at a power density of 0.5 kW kg-1. Also, the symmetric device capacity retention behavior achieves similar to 96.8% of the initial result after 5000 cycles, revealing the good stability of the electrode. Our findings offer a new way to further the development of high-performance energy devices.11Nsciescopu

Single flake homo p–n diode of MoTe2 enabled by oxygen plasma doping

Two-dimensional (2D) materials play a crucial role as fundamental electrical components in modern electronics and optoelectronics next-generation artificial intelligent devices. This study presents a methodology for creating a laterally uniform p–n junction by using a partial oxygen plasma-mediated strategy to introduce p-type doping in single channel MoTe2 device. The MoTe2 field effect transistors (FETs) show high electron mobility of about ∼23.54 cm2 V−1 s−1 and a current ON/OFF ratio of ∼106 while p-type FETs show hole mobility of about ∼9.25 cm2 V−1 s−1 and current ON/OFF ratio ∼105 along with artificially created lateral MoTe2 p–n junction, exhibited a rectification ratio of ∼102 and ideality factor of ∼1.7 which is proximity to ideal-like diode. Thus, our study showed a diversity in the development of low-power nanoelectronics of next-generation integrated circuits