CoS2 Nanoparticles Research Articles

Engineering active sites on N, S co-doped carbon matrix-encapsulated Ni-modified Co9S8 nanoparticles enabling efficient urea electrooxidation

Engineering active sites on N, S co-doped carbon matrix-encapsulated Ni-modified Co9S8 nanoparticles enabling efficient urea electrooxidation

High-Performance Cathodes Prepared via Liquid-Phase Method and Catalyzed by Co9S8 for All-Solid-State Lithium-Sulfur batteries

While all-solid-state lithium batteries and lithium-sulfur batteries are two advanced systems beyond the current generation of lithium-ion batteries and have been extensively studied for years, their combination (i.e., all-solid-state lithium-sulfur batteries, ASSLSBs) is seldomly explored. This paper herein demonstrates the success of making high-performance lithium sulfide cathodes for ASSLSBs. The composite cathode consists of the active material Li2S, a sulfide solid electrolyte Li6PS5Cl, a conductive carbon Ketjen Black, and a catalyst Co9S8 nanoparticles. Its preparation has the following features: mixing precursors via a liquid-phase method, in situ making Li6PS5Cl via calcination, and adding Co9S8 in the liquid-phase stage. Owing to the presence of Co9S8 nanoparticles and the liquid-phase process for ensuring excellent solid–solid interfaces among electrode constituents, the maximum capacity of the obtained electrode with Li2S-loading of 2 mg/cm2 in Li-In|Li6PS5Cl|cathode batteries is enhanced by 0.8 times and the maintaining capacity at the 100th cycle by 4.3 times. With high loadings of 10 mg/cm2, the cathode achieves a high areal capacity of 6.4 mAh/cm2 at room temperature, equivalent to energy densities of 598 Wh/kg, and maintain the retention ratio of over 80 % after 100 cycles. At 60 ℃, ultrahigh areal capacities of 9.4 mAh/cm2 and 14.1 mAh/cm2 can be achieved, equivalent to energy densities of 872 Wh/kg and 653 Wh/kg. Moreover, the mechanistic studies reveal that Co9S8 catalyzes all Li2S and also expedites the conversion between Li2S ↔ S by suppressing the polysulfides intermediates. Thus, this work opens the door of making high-performance Li2S cathodes for developing practical ASSLSBs.

Asymmetric supercapacitors assembled by hollow N, s co-doped carbon spheres decorated FeOOH and Co3S4 nanoparticles

Exploiting advanced anode and cathode materials with distinctive architectures and multi-component participation is of great significance to boosting the energy density of asymmetric supercapacitors. Herein, ultra-fine FeOOH nanoparticles are in situ grown on the hollow N, S co-doped carbon (HNSC) spheres using a facile solvothermal strategy and subsequent calcination process. Benefiting from the attractive hollow architecture and the synergistic effect between FeOOH and HNSC, the FeOOH/HNSC composite as anode for supercapacitors delivers an optimal capacity of 588.2 C g−1 (1 A g−1) and remains 88.3 % of its initial value after 10,000 cycles at 15 A g−1 in 6 M KOH. Furthermore, the HNSC-supported Co3S4 nanoparticles are also prepared through a one-step solvothermal strategy. The obtained Co3S4/HNSC composite as cathode achieves a capacity of 420 C g−1 (1 A g−1) and maintains a high retention of 95.3 % after 10,000 cycles at 15 A g−1. The constructed asymmetric supercapacitor using FeOOH/HNSC and Co3S4/HNSC as anode and cathode appears to possess a superior energy density of 82.3 Wh kg−1 at 821.6 W kg−1 with retention of 84.9 % after 10,000 cycles at 10 A g−1. These attainments demonstrate that constructing multi-component electrode materials with unique structures is an effective method to optimize the electrochemical characteristics of asymmetric supercapacitors.

Regional banks, financing constraints and manufacturing enterprises' total factor productivity: A quasi-natural experiment of China's city commercial banks

The literature shows that the financial system dominated by large national banks restricts enterprises' financing channels, leading to efficiency losses. In response, governments introduce different types of banks to address this issue. However, the literature overlooks the relationships among regional banks, financing constraints and manufacturing enterprises' productivity. We fill this gap by exploiting the China's unique policy of staggered rollout of city commercial banks across cities and using data from Chinese listed manufacturing enterprises over the period 1992 to 2022 to explore how regional banks affect productivity. We find that regional banks represented by city commercial banks in China significantly increase the manufacturing enterprises' total factor productivity by alleviating financing constraints, especially pronounced for state-owned enterprises, large enterprises, and well-established enterprises. Our research results emphasize the effectiveness of regional banks in promoting the development of the manufacturing industry and offer insights for sustainable economic development policies.

Interface-Engineered MoSe2-Co9S8 Nanoheterostructures with Enhanced Charge Storage Performance for Supercapacitor Application.

Cobalt-based chalcogenides have emerged as fascinating materials for supercapacitor applications owing to the presence of various mixed valance oxidation states in their structure along with rich electrochemical properties. However, their limited stability and cyclic performance hinder their viability for practical use in supercapacitors. Herein, a facile hot injection colloidal route is demonstrated to design MoSe2-Co9S8 nanoheterostructures (NHSs), which entails the epitaxial growth of Co9S8 nanoparticles (NPs) over the basal planes of ultrathin MoSe2 nanosheets (NSs). The interfacial engineering of the basal planes of MoSe2 NSs with Co9S8 NPs regulates the electronic properties and defects at the interfaces and increases the overall specific surface area and conductivity. As a result, MoSe2-Co9S8 NHSs electrode unveils a substantially higher specific capacitance of 910.5 F g-1 at 1 A g-1current density surpassing their individual counterparts. In addition, it demonstrates worthy solidity, retaining ≈90% of its capacitance and coulombic efficiency of 93.3% after 10,000 charge-discharge cycles at a high charge-discharge current density of 15 A g-1. As a proof-of-concept, coin cells are fabricated using MoSe2-Co9S8 NHSs which show 93% Coulomb efficiency and 86% capacitance retention. This study would pave the way for designing transition metal dichalcogenides (TMDs) - derived NHSs with superior capacitive properties.

In-situ nitrogen-doped carbon nanotube-encapsulated Co9S8 nanoparticles as self-supporting bifunctional air electrodes for zinc-air batteries

In-situ nitrogen-doped carbon nanotube-encapsulated Co9S8 nanoparticles as self-supporting bifunctional air electrodes for zinc-air batteries

Facile fabrication of N-doped RGO decorated CoS2 nanoparticles as advanced integrated electrode for enhanced supercapacitor performance

Transition metal sulfides (TMSs) are a class of advanced electrode materials for new energy storage devices with superior performance due to their many advantages, such as high specific capacity, good conductivity, low electronegativity, high redox activity, rich variety and low price. Herein, we developed N-doped reduced graphene oxide (N-RGO) decorated CoS2 nanoparticles nanohybrids (N-RGO/CoS2, denoted as NGCS) by a facile hydrothermal method. The doped-N process enriches the specific surface area and porosity of RGO nanosheets, which not only forms rich network nanostructures conducive to rapid charge/ion transport, but also promotes more dispersed anchoring of CoS2, resulting in the formation of smaller-sized CoS2 nanoparticles that can provide rich and exposed electroactive sites. Therefore, such unique hierarchical porous nanostructures help all components in the nanohybrids to “complement each other's strengths”, so that the fabricated NGCS electrode exhibits a high specific capacitance of 797.1 F g−1 at 0.6 A g−1 and an excellent rate capability with 77.5 % retention (20 A g−1). Furthermore, the assembled NGCS//AC hybrid supercapacitor (HSC) delivers excellent energy density of 41.4 Wh kg−1 (at 719.7 W kg−1) and long-term cyclability with 86.02 % capacitance retention after 13,000 cycles, presenting a promising application potential in new high-performance energy storage and conversion devices.

Coordination Compound Derived Co9S8 Supported on Nitrogen and Sulfur Co‐Doped Porous Carbon for Oxygen Reduction Reaction

AbstractCobalt sulfide, a class of metal chalcogenide with tunable electronic structure and component distribution, has attracted considerable interest in renewable energy conversion and utilization. In this work, we report a facile, efficient and scalable method to synthesize Co9S8 supported on nitrogen and sulfur co doped porous carbon (Co9S8/N,S‐PC) hybrid from the annealing treatment of a coordination compound assembled by 2‐mercaptobenzimidazole, 4,4‐bipyridine and cobalt salt. The heteroatom of organic ligand could efficiently tune the electronic properties of Co9S8 nanoparticles and well‐designed carbon. Meanwhile the interaction of organic ligands provides a platform for the high dispersion of Co9S8. Owing to the synergetic effect, the Co9S8/N,S‐PC catalyst shows an admirable oxygen reduction reaction (ORR) activity with the E1/2 of 0.804 V vs. RHE, together with good durability, and tolerance to methanol poisoning in alkaline media.

Innovative Air Cathode with Ni-Doped Cobalt Sulfide in Highly Ordered Macroporous Carbon Matrix for Rechargeable Zn-Air Battery.

To realize the practical application of rechargeable Zn-Air batteries (ZABs), it is imperative to develop a non-noble metal-based electrocatalyst with high electrochemical performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, Ni-doped Co9S8 nanoparticles dispersed on an inverse opal-structured N, S co-doped carbon matrix (IO─NixCo9-xS8@NSC) as a bifunctional electrocatalyst is presented. The unique 3D porous structure, arranged in an inverse opal pattern, provides a large active surface area. Also, the conductive carbon substrate ensures the homogeneous dispersion of NixCo9-xS8 nanocrystals, preventing aggregation and increasing the exposure of active sites. The introduction of heteroatom dopants into the Co9S8 structure generates defect sites and enhances surface polarity, thereby improving electrocatalytic performance in alkaline solutions. Consequently, the IO─NixCo9-xS8@NSC shows excellent bifunctional activity with a high half-wave potential of 0.926V for ORR and a low overpotential of 289mV at 10mA cm-2 for OER. Moreover, the rechargeable ZAB assembled with prepared electrocatalyst exhibits a higher specific capacity (768 mAh gZn -1), peak power density (180.2mW cm-2), and outstanding stability (over 160h) compared to precious metal-based electrocatalyst.

Partially Amorphous Ru-Doped CoSe Nanoparticles with Optimized Intermediates Adsorption for Highly Efficient Sulfur Oxidation Reaction.

The application of thermodynamically more favorable sulfur oxidation reaction (SOR) to replace oxygen evolution reaction (OER) in electrocatalytic water electrolysis is an appealing strategy to achieve low-energy hydrogen production while removing toxic sulfur ions from wastewater. However, the study of SOR catalysts with both activity and stability still faces great challenges. Herein, this study prepares partially amorphous Ru-doped CoSe (pa-Ru-CoSe) nanoparticles for SOR. The doping of Ru keeps Co in an electron-deficient state, which enhances the adsorption of SOR intermediates and improves the catalytic activity. Meanwhile, the partially amorphous selenide possesses great corrosion resistance to sulfur species, thus ensuring stability in long-term SOR. In addition, the pa-Ru-CoSe requires only 0.566V to reach a current density of 100mA cm-2 in the SOR-HER coupled system and remains stable for 200 h. This work provides a promising partially amorphous strategy for SOR catalysts with both catalytic activity and long-term stability, enabling hydrogen production with low energy consumption and simultaneous sulfur production.

Construction of a multiple reactive species-mediated Co9S8/NBC-PMS Fenton-like system for tetracycline degradation with broadened adaptability to water background

A Fenton-like system based on peroxymonosulfate (PMS) oxidant has high potential for antibiotic degradation, However, various complex water background factors, including pH, coexisting ions, and dissolved organic matter, can adversely affect degradation efficiency. This work constructed a PMS oxidative Fenton-like system activated by cobalt polysulfide/N-doped biochar composite (Co9S8/NBC) for the degradation of tetracycline (TC) and achieving approximately 99 % removal of TC. Furthermore, the removal efficiency was maintained above 90 % across a broad pH range (3−11), in the presence of various coexisting anions (Cl−, NO3− and CO32−), even at high concentrations of humic acid. The characterization of Co9S8/NBC through various techniques confirmed that Co9S8 nanoparticles were uniformly loaded within the porous NBC structure. Electron paramagnetic resonance and reactive oxygen species (ROSs) quenching experiment revealed that the effectiveness of TC degradation in the Co9S8/NBC/NBC-PMS system arises from the cooperation of radical and non-radical species rather than the single mechanism. Moreover, the analysis of the contribution ratios of ROSs to TC degradation indicates that the contribution of non-free radicals exceeds that of free radicals, and it is capable of adapting to changes in pH. The characterization of the post-reaction catalyst suggested that Co9S8 and NBC synergistically participated in the activation of PMS. Moreover, the practical examination proved that the disabled Co9S8/NBC catalyst can recover the catalytic activity via a reheat treatment, the leaching concentration of Co ions was lower than the emission limit of China. The river water and lake water as the matrix water have little negative impact on the degradation of TC. The Co9S8/NBC-PMS system is expected to provide a practical pathway for the treatment of antibiotic wastewater.

Enhanced photocathodic protection performance of Co3S4 nanoparticles modified porous BiVO4 composites for 304 stainless steel

A nanoporous Co3S4/BiVO4 composites were successfully fabricated via electrodeposition, immersion and oil-bath heating methods. ZIF-67 was used as a cobalt source and template. Co3S4/BiVO4 obtained by treatment for 6 h displayed the best photocathodic protection (PCP) performance. Under light, Co3S4–6 h/BiVO4 reduced the potential of 304 stainless steel (SS) to −490 mV vs. SCE, which was 200 mV below that of pure BiVO4. In addition, the photocurrent densities of 304 SS coupled with Co3S4–6 h/BiVO4 were up to 13 μA cm−2, which was more than 4 times that of pure BiVO4. Remarkably, the Rct of 304 SS coupled with Co3S4–6h/BiVO4 (142.6 Ω·cm2) was 1/27 of that of pure BiVO4 (3918 Ω·cm2). The outstanding PCP property of Co3S4/BiVO4 can be owed to the synergistic effects of strong visible light absorption, improved charge transfer efficiency, and enhanced electron storage capacity. These advantages make Co3S4/BiVO4 a promising candidate for providing effective PCP effects on metals.

The application of Co3S4@NCNT/NCHS with excellent bifunctional catalytic activity in aqueous and flexible Zn-air batteries

In this work, we prepared a hybrid structure Co3S4@NCNT/NCHS using SiO2 nanospheres as a template. The structure is supported by hollow carbon spheres (NCHS), which are coated by Co3S4 nanoparticles and cross-linked N-doped carbon nanotubes. The combination of Co3S4 with N-doped carbon material significantly improves the electrocatalytic activity. In addition, the presence of N-doped carbon nanotubes induces more defects, which can regulate the electronic configuration of the material and improve its electrical conductivity. Therefore, Co3S4@NCNT/NCHS has good catalytic performance. At 10 mA cm−2, the OER overpotential of Co3S4@NCNT/NCHS is only 230 mV, which is lower than that of the commercial catalyst RuO2, and the ORR half-wave potential can reach 0.80 V. In the battery discharge test, Co3S4@NCNT/NCHS based ZABs can discharge continuously for 71.5 h, the specific capacity of 790.12 mA h g−1, power density of 113.09 m W cm−2, better than Pt/C+RuO2 battery. When the current density is 3 mA cm−2, ZABs assembled with Co3S4@NCNT/NCHS as catalyst can maintain a voltage gap of 0.62 V to 0.63 V within 300 h without significant change. When the current density is increased to 5 mA cm−2, ZABs based on Co3S4@NCNT/NCHS can be stably cycled for 300 h at a voltage gap between 0.80 V and 0.82 V.

CoSe2 nanocrystals embedded in one-dimensional mesoporous carbon nanofibers as advanced anode for potassium-ion storage

High-performance potassium-ion batteries have received great attention for electrochemical energy storage owing to their low redox potential, abundant natural resources and excellent safety. As an advanced negative material, CoSe2 has been widely investigated for potassium-ion batteries. Unfortunately, the pure CoSe2 anode suffers from the fast capacity decay and sluggish kinetics, preventing its practical application. Herein, we introduce a novel strategy to fabricate the CoSe2 nanoparticles embedded in one-dimensional mesoporous carbon nanofibers (denoted as 1D-CoSe2@CNFs) with superior high-rate property and good cycle stability for the first time. In this designed material, the conductive carbon nanofibers are loaded with CoSe2 particles. The obtained 1D-CoSe2@CNFs anode shows a specific capacity of 706.3 mAh/g at 0.1 A/g and presents a high capacity retention ratio of around 96.3 % at 5 A/g over 400 cycles. Therefore, this fabricated 1D-CoSe2@CNFs nanocomposite can be employed as a novel negative electrode for potassium-ion storage.

Coating of CoS on hybrid anode electrode with enhance performance in hybrid dye-sensitized solar cells

Improvement of the power generation performance of dye-sensitized solar cells (DSSCs) remains a key task, as charge transfer and charge separation are efficiently achieved at the photoanode and between the polysulfide electrolyte interface and the counter-electrode. We synthesized the metal sulfides from dithiocarbamate complexes and used them to fabricate a new modified cell by passivating the photoanode electrode with CoS nanoparticles and SnS as photosensitizer in a two-step deposition approach. They were used as FTO-TiO2/CoS/SnS/HI-30/FTO-Pt, known as C-S-1, C-S-2 and C-S-3. SEM images show that the C-S-1 and C-S-2 are uniform, without cracks and have a dense surface morphology covering the surface area. Thus, confirming the successively passivation by CoS and sensitization of SnS, forming FTO-TiO2/CoS/SnS heterostructure. The η of 8.79% and 9.43% are much higher than that of C-S-2, with 0.23% affirm the roles of the Co, Sn and S ratio on both devices. The EIS Nyquist plot for the C-S-2 device shows a semicircle radius smaller than the C-S-1 and C-S-3, which indicates more efficient inhibition of electron/hole pairs and faster transportation of photogenerated charge carriers. The enhanced performance of both devices shows that the passivation of the electrodes ensures that maximum absorption is achieved through a higher absorption coefficient of SnS. Also, both devices reach a steady state within about 200–300 s and remain at the steady state current for a long duration for C-S-1 and C-S-3. The enhanced performance of both devices shows that the passivation of the electrodes ensures that maximum absorption is achieved through a higher absorption co-efficient of SnS.

Investigating the Z-scheme mechanism on the optimized oxygen vacancies ZnO/Co3S4 photocatalyst for the efficient photocatalytic removal of ciprofloxacin

The waste of human and animal antibiotics is an inescapable problem and a severe threat to the continuation of human life. A logical strategy to face the challenge of antibiotic contamination is to design active, stable, environmentally friendly, and economical photocatalysts. Hence, oxygen vacancies ZnO/Co3S4 (ZnO-OV/Co3S4) photocatalyst was successfully fabricated for the first time and used for the photocatalytic removal of ciprofloxacin (CIP) as a widely used antibiotic under visible light. Several techniques were engaged in exploring the crystallinity, morphology, structure, chemical and elemental composition, and electrochemical and optical properties of the constructed nanocomposites. The band gap of ZnO-OV and Co3S4 nanoparticles was determined at 2.95 and 1.58 eV by evaluating the optical properties and using the Tauc plots. To optimize the conditions of the photocatalytic process, factors such as the weight percentage of the nanocomposite components, the photocatalyst dosage, the initial concentration of CIP, the pH of the test solution, and the presence of bubbled oxygen were varied. The optimal degradation rate constant (0.0720 min−1) was obtained for ZnO-OV/Co3S4 (15 %) nanocomposite at pH 9, nanocomposite dosage of 1.5 g/L, and 10 mg/L of CIP in the visible spectrum. The experimental and characterization outcomes indicated that the significantly boosted photocatalytic activity of the ZnO-OV/Co3S4 composite was chiefly attributed to the oxygen vacancies, retard charge carriers recombination by the construction of heterojunction between the ZnO-OV and Co3S4. Finally, the possible Z-scheme mechanism was proposed to illuminate the migration of charge carriers.

Unveiling the Enhancement of Electrocatalytic Oxygen Evolution Activity in Ru-Fe2O3/CoS Heterojunction Catalysts.

The development of highly efficient electrocatalysts for the sluggish anodic oxygen evolution reaction (OER) is crucial to meet the practical demand for water splitting. In this study, an effective approach is proposed that simultaneously enhances interfacial interaction and catalytic activity bymodifyingFe2O3/CoS heterojunctionusing Ru doping strategy to construct an efficient electrocatalytic oxygen evolution catalyst. The unique morphology of Ru doped Fe2O3 (Ru-Fe2O3) nanoring decorated by CoS nanoparticles ensures a large active surface area and a high number of active sites. The designed Ru-Fe2O3/CoS catalyst achieves a low OER overpotential (264mV) at 10mAcm-2 and demonstrates exceptional stability even at high current density of 100mAcm-2, maintaining its performance for an impressive duration of 90h. The catalytic performance of this Ru-Fe2O3/CoS catalyst surpasses that of other iron-based oxide catalysts and even outperforms the state-of-the-art RuO2. Density functional theory (DFT) calculation as well as experimental in situ characterization confirm that the introduction of Ru atoms can enhance the interfacial electron interaction, accelerating the electron transfer, and serve as highly active sites reducing the energy barrier for rate determination step. This work provides an efficient strategy to reveal the enhancement of electrocatalytic oxygen evolution activity of heterojunction catalysts by doping engineering.

N-doped one-dimensional carbon framework embedded with CoSe2 nanoparticles as superior electrode for advanced sodium ion storage

Cobalt selenide (CoSe2) is acknowledged as a negative electrode material for sodium-ion batteries (SIBs) due to its high theoretical capacity. However, the significant volume change and inadequate electrochemical performance during charge and discharge processes have limited its practical use in batteries. In this investigation, a straightforward and practical electrospinning method combined with selenization reaction was utilized to fabricate CoSe2 nanoparticles enclosed in nitrogen-doped carbon nanofibers with a three-dimensional self-supporting network structure (CoSe2/N-PCNFs).The CoSe2/N-PCNFs electrode has self-supporting and high conductivity properties, as an anode material for sodium-ion batteries, the discharge capacity of the composite material can reach 450.1 mAh/g after 100 cycles at a current density of 0.2 A/g, and can still maintain a large discharge capacity of 396.9 mAh/g after 500 cycles at a high current density of 1 A/g. The outstanding electrochemical performance is mainly attributed to the superior specific surface area, controllable porous structure, and high pore volume of CoSe2/N-PCNFs Experimental and density functional theory calculations both indicate that the heterojunction interface between CoSe2 and nitrogen-doped carbon can not only promote the adsorption of Na+, but also facilitate electron transfer to significantly improve the rate capability of the material.

Large ligand metal-organic framework derived CoSe2 to improve sodium storage performance

Cobalt selenide has been regarded as a promising anode for sodium-ion battery owing to its high capacity. However, the issues of stacked problem and volume expansion during cycling significantly affects its performance. Herein, we used large-size ligands to successfully prepared a new cobalt metal–organic frameworks (MOFs), and used as a precursor to prepare CoSe2/MOFc by high-temperature selenization. Morphology characterizations revealed that due to the blocking effect of large-sized ligands, CoSe2 nanoparticles were evenly distributed on the carbon material. As an anode, CoSe2 /MOFc shows a good cyclic stability and high capacity (291 mAhg−1 after 1000 cycles at 1 Ag−1) due to the well dispersion of CoSe2 nanoparticles and the effective coating of carbon matrix. These results indicated that utilizingMOFs precursor with large ligands facilitates the distribution of nanoparticles on conductive carbon, allowing for the synthesis of sodium-ion battery electrodes with superior properties.

Synthesis and Application of Titanium Carbide (Ti3C2)-Cobalt Sulfide (Co3S4) Nanocomposites in Amino Acid Biosensing.

Background The fabrication of titanium carbide (Ti3C2)-cobalt sulfide (Co3S4)-based biosensors with high sensitivity and selectivity can change the biosensor manufacturing industry completely. Molecular and clinical diagnostics, disease progression monitoring, and drug discovery could utilize these sensors for early biomarker detection. MXene (Ti3C2) is a two-dimensional material with exceptional electrical conductivity, hydrophilicity, great thermal stability, large interlayer spacing, and a high surface area. Ti3C2'sremarkable characteristics make it well-suited for biomolecule immobilization and target analyte detection. Co3S4is a transition metal chalcogenide that has shown great potential in biosensors. Co3S4 nanoparticles (NPs) can potentially enhance Ti3C2 electrocatalytic activity, particularly in amino acid detection. L-arginine is a semi-essential amino acid, and the body frequently uses it to support healthy circulation and plays a crucial role in protein synthesis. We fabricated the Ti3C2-Co3S4 biosensor for L-arginine detection. Aim This study aims to synthesize and apply Ti3C2-Co3S4 nanocomposites in amino acid biosensing. Materials and methods The Ti3C2 nanosheets were synthesized by the selective removal of an aluminum (Al) layer from the precursor (Ti3AlC2) using hydrofluoric acid (HF). The resulting mixture serves as an etchant, especially targeting the Al layers on Ti3AlC2while protecting the desired MXene layers at room temperature. Cobalt nitrate hexahydrate was dissolved in deionized water. Sodium hydroxide was added to the cobalt solution and stirred. Thioacetamide was added to the above solution and stirred (Solution B). A mixture of Solution A and Solution B was stirred for 30 minutes. The mixture is transferred to a hydrothermal reactor and maintained at a temperature of 180°C for 12 hours. Once the reaction completes, we cool the resultant mixture to room temperature and then filter it using the washing technique. The sample underwent a 12-hour drying process at 80°C. Results This study investigated the use of a biosensor that employed Ti3C2-Co3S4 NPs to detect the concentration of L-arginine. The X-ray diffraction (XRD) shows clear and distinct peaks, which means that the synthesized Ti3C2-Co3S4 nanostructures have a crystalline structure.Scanning electron microscopy (SEM) analysis revealed that the sheetlike structure of synthesized Ti3C2-Co3S4 nanostructuresrevealedthe crystalline morphology. The results of this study show that the Ti3C2-Co3S4NP-based biosensor can be used to detect L-arginine in a sensitive and selective way. Conclusion This study investigated the synthesis of Ti3C2-Co3S4NPs and their ability to detect L-arginine levels and show a distinct correlation between the L-arginine concentration and the fluorescence intensity, demonstrating the biosensor's effectiveness in detecting L-arginine levels.