rGO Sheets Research Articles

Amide coupled Si-rGO hybrids as anode material for lithium-ion batteries

Despite silicon (Si) having a high specific capacity of 4200 mA h/g, it undergoes significant expansion in volume during lithiation. In order to alleviate the significant increase in volume that occurs in silicon nanoparticles (SiNPs) of lithium-ion batteries, herein we report covalently modified SiNP contained within reduced graphene oxide (rGO) sheets as an anode material in lithium-ion batteries (LIBs). The structural modification of SiNP could effectively mitigate the increase in volume while preserving its outstanding electrochemical properties. Graphene oxide (GO) undergoes chemical modification and functionalization by a simple and efficient method using microwave-assisted sonochemical approach. The procedure entails grafting carboxyl functionalized silicon nanoparticles (C-Si) to amine-functionalized reduced graphene oxide (NH2-rGO) to produce a Si-rGO hybrid via amide linkage. This hybrid reduces the problem of volume expansion in Si anodes by dissipating substantial changes in volume and minimizing direct contact between SiNPs and the electrolyte. The formation of a robust solid electrolyte interface (SEI) layer improves the specific capacity and durability of the anode material. We observed that the Si-rGO 2 hybrid (containing 44 wt% Si) exhibited a relatively higher specific capacity of 1604 mA h/g during the initial cycle at C/10 rate when compared to other hybrid systems, such as Si-rGO 1, Si-rGO 2, Si-rGO 3 with bare SiNP, and SRGO composite (without amide linkage). Additionally, it maintained a capacity of approximately 1000 mA h/g at C/2 rate for more than 125 cycles. Thus, enhanced specific capacity, cycling stability, electrode conductivity, and lithiation are made possible due to the structural modification of SiNPs.

One-pot synthesis and characterizations of highly conductive reduced graphene oxide-silver nanohybrid at various reaction time

Silver nanoparticles (AgNPs) were incorporated with reduced graphene oxide (rGO) sheets to form rGO-Ag nanohybrid. The nanohybrid was synthesized using galactose as both reducing and stabilizing agents in various reaction times (4, 8, 16, and 24 hours). Its morphological and structural characteristics were analyzed using UV–Visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Raman Spectroscopy. Electrical conductivity was assessed with a two-point probe method. The 16 hours synthesis time produced the best results: UV–Vis confirmed monodispersed spherical AgNPs on rGO; XRD indicated a crystallite size of 11.83 nm; and HRTEM showed the formation of AgNPs with average size 11 nm. Additionally, 16-h rGO-Ag nanohybrid exhibited the lowest resistance (68.82 Ω) and highest conductance (14.52 × 10−3 Sm−1). Consequently, this sample demonstrates superior electrical properties, making it ideal for various electrical device applications.

Nanoarchitectonics with reduced graphene oxide nanosheets for photo- and humidity sensing properties

The present study explores the photo- and humidity sensing properties of reduced graphene oxide (rGO) sheets at room temperature. Graphite powder was chemically oxidized using a modified Hummer's approach to produce rGO sheets. The physicochemical traits of the rGO sensor were analyzed by various characterization techniques, including X-ray diffraction (XRD), UV–vis absorption spectra, Raman spectroscopy, field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HR-TEM). Raman spectroscopic micrograph exhibits two vibrational modes: D-band at 1329 and G-band at 1587 cm−1. The rGO photosensor shows a maximum responsivity of about 7.22 AW−1 with quick response and recovery times. The sensor showed a maximum sensitivity of 37 % in humid environments, with response and recovery durations of 44 s and 126 s, respectively. The rGO-based sensor showed excellent photosensitivity, exceptional stability, and a better response to photo and humid environments. The excellent performance of rGO sheets proves to be a promising functional material in sensing devices.

Controlled synthesis of CuCo2S4@CuCo2O4 nanoflowers decorated over the rGO sheets for eletrochemical supercapacitor

Controlled synthesis of CuCo2S4@CuCo2O4 nanoflowers decorated over the rGO sheets for eletrochemical supercapacitor

Reduced graphene oxide-supported Na3V2(PO4)3/C cathode material synthesized by sol-gel method to improve electrochemical performances of sodium-ion batteries

Na-ion batteries are potential alternative to Li-ion batteries due to their low cost and abundance of sodium source. And Na3V2(PO4)3 is regarded as the most promising cathode material because of their high capacity and larger interstitial channels for fast Na ion migration. However, the disadvantage of low conductivity suppresses its practical applications. To increase electrochemical properties of the cathode, reduced graphene oxide-supported Na3V2(PO4)3/C (NVP/C-G) composite has been prepared, in which the graphene is used to accelerate movement of the electronics and Na ions. XRD characterizations show that the synthesized material is well corresponding to NASICON structure, and SEM image show that the graphene sheets are uniformly dispersed on surface of the composite. The initial capacity of the material is up to 103.5 mAh g−1 at 0.1 C, and 92.3 % and 92.1 % of capacities are maintained with discharge ratios of 0.5 C and 2 C over 500 cycles, proving a much better cycling stability compared with the Na3V2(PO4)3/C (NVP/C) particles. The enhanced discharge capacities and retention rate of the NVP/C-G could be ascribed to the tight contact between NVP/C and RGO sheets, which is beneficial to fast electron transport and better intercalation/deintercalation of Na+ through the nanoparticles. Therefore, the synthesized NVP/C-G displays highly potential for practical use in sodium-ion batteries.

Nacre inspired supertough and flame-retardant reduced graphene oxide composite films

Nacre-like graphene composite films (GCFs) with high strength have been highly developed. However, the GCFs usually exhibit relatively poor toughness and poor flame resistance, seriously limiting their applications as structural materials. Here, reduced graphene oxide (rGO), halloysite nanotubes (HNTs), and flame-retarding modified lignin (F-lignin) were compounded to fabricate the rGO-HNTs-(F-lignin) film. In the rGO-HNTs-(F-lignin) film, the F-lignin binds the rGO sheets and HNTs, enhancing the entanglement of HNTs and the interactions between HNTs and rGO sheets, and the macromolecular F-lignin also improves the ductility of the rGO-HNTs-(F-lignin) film, while the entangled HNTs conversely reinforce the F-lignin to prevent the F-lignin from fracture when the rGO-HNTs-(F-lignin) film is under stress, further increasing the ductility of the rGO-HNTs-(F-lignin) film. The HNTs and F-lignin promote each other to enhance the strengthening and toughening effect on the rGO-HNTs-(F-lignin)-film, and endowing the rGO-HNTs-(F-lignin)-film with the superior mechanical properties of the tensile strength of 634 ± 38 MPa, tensile fracture strain of 8.17 ± 0.59 %, and toughness of 25.35 ± 2.95 MJ/m3, respectively. The rGO-HNTs-(F-lignin) film also exhibits improved flame-retardant properties due to the high flame retardancy of HNTs and F-lignin. These excellent integrated properties of the rGO-HNTs-(F-lignin) film will promote its potential applications as structural materials.

Ag-Cu2O Supported Biomass-Derived rGO for Catalyzing Suzuki-Miyaura Cross-Coupling.

The search for cost-effective, efficient, and ecofriendly heterogeneous catalysts for the Suzuki-Miyaura reaction is crucial due to challenges with expensive, toxic homogeneous catalysts. This study centrally aims at crafting a pioneering green catalyst by adorning reduced graphene oxide (rGO), sourced from basil seeds (Ocimum basilicum L.), with an Ag-Cu2O composite structure. Comprehensive characterization of the Ag-Cu2O/rGO nanocomposite was conducted through FTIR, SEM, hHR-TEM, EDS, XPS, XRD, TGA, and N2 adsorption/desorption analyses. Results showed that nanosized Ag-Cu2O particles were partially integrated into rGO sheets derived from basil seeds, acting as active species for oxidative addition with aryl halides in the SMR. The catalytic efficacy of this robust nanocatalyst was assessed in Suzuki-Miyaura cross-coupling reactions, targeting the synthesis of biaryls employing various aryl halides and aryl boronic acids. The findings underscore that the Ag-Cu2O/rGO nanocatalyst manifests rapid reaction kinetics (15 min) alongside commendable yields (99%). The Ag-Cu2O/rGO demonstrates impressive recyclability, maintaining catalytic efficiency over four cycles. Utilizing it as a green substrate for metal loading highlights its potential, offering well-defined coordination sites. This approach facilitates stable heterogeneous catalyst fabrication, crucial for significant bond formations. Notable features include broad applicability, exceptional functional tolerance, scalability, and practicality. Moreover, it holds promise for automating safe processes and enabling efficient late-stage functionalization of complex molecules with moderate to high efficiency, presenting promising prospects for various applications in chemical synthesis.

Green and solid state reduction of GO monolayers sandwiched between Arachidic acid LB layers

A novel, single step and environment friendly solid state approach for reduction of graphene oxide (GO) monolayers has been demonstrated, in which, arachidic acid/GO/arachidic acid (AA/GO/AA) sandwich structure obtained by Langmuir-Blodgett (LB) technique was heat treated at moderate temperatures to obtain RGO sheets. Heat treatment of AA/GO/AA sandwich structure at 200 °C results in substantial reduction of GO, with concurrent removal of AA molecules. Such developed RGO sheets possess sp2-C content of ∼69 %, O/C ratio of ∼0.17 and significantly reduced I(D)/I(G) ratio of ∼1.1. Ultraviolet photoelectron spectroscopy (UPS) studies on RGO sheets evidenced significant increase in density of states in immediate vicinity of Fermi level and decrease in work function after reduction. Bottom gated field effect transistors fabricated with isolated RGO sheets displayed charge neutrality point at a positive gate voltage, indicating p-type nature, consistent with UPS and electrostatic force microscopy (EFM) measurement results. The RGO sheets obtained by heat treatment of AA/GO/AA sandwich structure exhibited conductivity in the range of 2–7 S/cm and field effect mobility of 0.03–2 cm2/Vs, which are comparable with values reported for RGO sheets obtained by various chemical/thermal reduction procedures. The extent of GO reduction is determined primarily by proximity of AA molecules and found to be unaltered with either escalation of heat treatment temperature or increase of AA content in sandwich structure. The single-step GO reduction approach demonstrated in this work is an effective way for development of RGO monolayers with high structural quality towards graphene-based electronic device applications.

Hydrothermal synthesis of cadmium sulfide decorated reduced graphene oxide photocatalyst for the degradation of photostable naphthol blue black dye

Photocatalysis is being used for the mineralization of recalcitrant organic pollutants in water that cannot be treated with conventional methods. Cadmium sulfide decorated reduced graphene oxide (rGO-CdS) nanocomposite photocatalyst was synthesized by hydrothermal method and evaluated for the removal of a photostable textile azo dye, naphthol blue black (NBB) under ultraviolet light (UV-A, 365 nm). The rGO-CdS combination was opted for due to utilizing the narrow band gap (Eg = ~2.4 eV) of CdS and robust rGO support, capable of attracting organic pollutants to surface, bear, and protect CdS from photocorrosion. The formation of rGO-CdS was proved from the findings of physiochemical characterization UV–visible-, X-ray diffraction photoelectron, Raman, energy dispersive X-ray-spectroscopic, and scanning, transmission electron, and atomic force microscopic studies. The spherical CdS was decorated on the random shaped rGO sheets. Eg of CdS and rGO-CdS were 2.42 and 2.39 eV, respectively. After 2 h of light exposure, 2 g/L of rGO-CdS mineralized 95 % of NBB (2 × 10−4 mol/L). After 5 cycles, 80 % of photocatalytic efficiency was retained. In gas chromatography-mass spectrometry studies, 8 fragments of NBB were found after 1 h and confirmed that the degradation was mediated by photocatalytic dilapidation. The optimum pH for NBB degradation was 9. The rGO-CdS was found to be a potentially stable and reusable photocatalyst for environmental applications.

Highly sensitive disposable test strips for sweat chloride detection using silver nanoparticles decorated reduced graphene oxide

The quantification of chloride ions in sweat by a point-of-care test system is a useful strategy in the early screening of cystic fibrosis. In this context, silver nanoparticles decorated reduced graphene oxide were synthesized by one-pot reduction method in this work. This reaction in situ produces silver nanoparticles spread across thin sheets of rGO with high surface area. This helps in the electrochemical detection of chloride ions by conversion of silver to silver chloride and formation of a thin layer of silver chloride on the surface of nanocomposite. The validity of this strategy has been demonstrated by voltammetric analysis of chloride ions using the screen-printed Ag-rGO nanocomposite. For electrodes tested in buffer, the sensitivity was 37.66 ± 0.99 mA (log mM)−1 cm−2 with a high selectivity and detection range from 30 to 400 mM chloride concentration. The lower detection limit is 1.02 mM (S/N = 3), and the relative standard deviation (RSD) of sensor response is 4.77 %. Disposable sensor test strips fabricated with screen printing of the catalyst followed by layer by layer array of electrolyte and hydrophilic membrane shows a sensitivity of 165.2 ± 4.3 µA mM−1 cm−2, a linear detection range upto 210 mM, and a LOD of 2.46 ± 0.06 µM. The quantification of the developed sensor strips were confirmed by comparing the values from clinical laboratories. This finding confirms the potentiality of the developed method and its possible application in the rapid and easy-to-use point-of-care devices. Notable advantages of the Ag-rGO nanocomposite is its reversibility due to the regeneration of fresh silver nanoparticles on the rGO surface and increased electrochemical response. This feature realizes a high stability even at multiple trials with a RSD of 2.63 % and long-time storage tested upto 3 months. Using this superior performance, the developed sensor test strip demonstrates a disposable, non-invasive, reproducible, reversible, highly selective, and sensitive monitoring of chloride ions.

Fly ash-based zeolite/reduced graphene oxide/polymer anti-corrosion coatings for efficient heat dissipation

Industries are demanding more and more for the high corrosion protection and thermal conductivity of organic coatings. However, organic coatings always have low thermal conductivity, and the effective distribution of inorganic particles within these organic coatings remains imperative for further enhancing both anti-corrosion and thermal conductivity capabilities simultaneously. Herein, a novel method is introduced for the exfoliation of reduced graphene oxide (rGO) through wet ball milling, incorporating fly ash-based zeolites. The resulting particles (A-rGO) formed two structures: rGO sheets wrapped around or partially loaded on the surface of zeolite particles. Notably, the absolute zeta potential of A-rGO measures 47.8, marking a 4.26-fold increase compared to rGO, thereby facilitating enhanced dispersion within the coating matrix. Then, benzoxazine/A-rGO based coatings are made, which formed a thermally conductive pathway and constructed an anti-corrosion barrier. The results showed that the highest thermal conductivity of the prepared coating (A-r-2) was as high as 1.561 W·m−1 K−1, which was 676.1 % higher than that of benzoxazine based coating, and 159.7 % higher than that of the same content of benzoxazine/rGO coating. Furthermore, the low-frequency impedance value of the A-r-2 coating reached 2.433 × 109 Ω·cm2 with a water contact angle as high as 129.8 ± 0.2°. The particles designed in this study provides a new system additive for fabricating highly thermally conductive composite coatings with high corrosion resistance.

Rigid-flexible coupling multistage carbon composite materials based on hybrid crosslinking as anodes for ultra long-cycling lithium-ion batteries

Graphene have garnered considerable attention owing to their disordered structure, wide layer spacing, and cost-effectiveness. The hierarchical porous structure of porous reduced graphene oxide (rGO) nanosheets with hollow carbon nanospheres offers advantages such as an intact conductive network and a robust structure. However, since the hollow carbon nanospheres are physically in contact with rGO, they are randomly dispersed on the graphene surface, severely impeding fast electron transport and resulting in poor electrochemical performance. In this study, we introduced a third layer of a polypyrrole (PPy) -derived carbon film on the basis of porous rGO sheets and hollow carbon nanospheres. The HCGP-200 anode was successfully prepared to effectively encapsulate hollow carbon nanospheres on rGO sheets through the synergistic effect of rGO and the PPy-derived carbon film. The HCGP-200 anode exhibits robust cycling performance (780 mAh g−1 after 2200 cycles at 5 A g−1) and excellent rate capacity. Additionally, it demonstrates outstanding cycling stability and remarkable capacity retention (450 mAh g−1 after 3000 cycles) even at ultra-high current densities of 20 A g−1. The ingenious design and preparation of HCGP-200 is of great significance in guiding the application of high-power appliances.

Electrochemical behaviour of ZrS2@rGO nanohybrid for high-performance supercapacitors

The batteries and capacitors have limited energy storage capacity due to reduced electrochemical performance and cycle stability. The existence problem can be overcome by fabricated nanostructured materials via enhanced electrical conduction and a significant surface area are essential for fulfilling the key requirements in evaluating as excellent electrode used in supercapacitors application, like as stability and extraordinarily high performance. This study utilises a cost-effective sonochemical approach to fabricate a ZrS2@rGO nanohybrid. The synthesized ZrS2 and ZrS2@rGO nanohybrid electrode were analyzed by their structural behaviour, oxidation state and morphological properties by utilising X-ray diffractometry (XRD), X-ray photoelectron spectroscopy and scanning electron microscopy (SEM) to verify the fabricated material. The addition of rGO sheets to ZrS2 particles enhances the surface area as well as capacitance of the ZrS2@rGO nanohybrid due to superior adsorption of electrolyte ions. The ZrS2@rGO nanohybrid demonstrated exceptional stability and attained the exceptional capacitance (Cs) of (1237.9 F/g) @ 1 A/g and the energy (68.5 Wh/kg), power density (Pd) of 315.7 W/kg during GCD (galvanostatic charge/discharge) analysis by utilising three-electrode setup. The ZrS2@rGO nanohybrid exhibits exceptional electrochemical properties, which proved to be an excellent material for their significant storage, unlike batteries and simple capacitors, as well as used as considerable potential for future technological advancements and energy storage devices.

Two-Dimensional (2D) Layered Metal–Organic Framework (MOF) Composites as an Electrochemical Sensor for Nitrofurans

A two dimensional layer iron metal–organic framework (MOF), [Fe (bipy)(C4O4)(H2O)2]×3H2O (where bipy = 4,4’-bipyridine、 C4O4 2- (squarate) = dianion of squric acid) has been successfully synthesized. Hydrothermal synthesis was employed to incorporate these Fe-MOFs into reduced graphene oxide (rGO) nanosheets, forming Fe-MOF/rGO composites. SEM, TEM, XRD, XPS, and contact angle measurements were employed to analyze the composites. TEM studies revealed that the rod-shaped Fe-MOFs were uniformly dispersed on the rGO sheets. Incorporating Fe-MOF into rGO resulted in enhanced performance, which can be attributed to the composites' large surface area, chemical stability, and high electrical conductivity. The Fe-MOF/rGO modified electrodes exhibited significantly improved response signals for the electrochemical sensing of nitrofurazone, showcasing a lower detection limit. The sensor also demonstrated reproducible and stable anti-interference properties. To elucidate the mechanism behind the enhanced sensing performance, grand canonical Monte Carlo (GCMC) calculations were conducted. These calculations indicated that the interface between Fe-MOF and rGO effectively absorbed an increased number of NFZ molecules. These findings underscore the substantial improvement in the electrochemical performance of Fe-MOF/rGO composites, positioning them as promising materials for practical applications in nitrofurazone sensing.

Boosting supercapacitor performance: Sb2O3 nano-blocks on rGO sheets for enhanced energy storage

In this work, the synthesis of antimony(III) oxide (Sb2O3) nanoblocks/reduced graphene oxide (rGO) sheets was obtained by a straightforward hydrothermal method. Sb2O3/rGO composites were prepared with various ratios of rGO. The results indicated that the Sb2O3/15 mg rGO composite had remarkable electrochemical performance. It displayed a good electrochemical efficiency, with a high specific capacitance of 151.89 F g−1 at 1 A g−1. Furthermore, it demonstrated a significant cycling stability, retaining 80 % of its initial capacitance after 5 K charge/discharge cycles. A symmetric supercapacitor device was prepared using Sb2O3/15 mg rGO composite as the electrodes for both positive and negative ends. The device exhibited a high specific energy of 44.36 Wh kg−1 and a significant specific power of 850.76 W kg−1. Moreover, it maintained 5.025 Wh kg−1 at a specific power of 7.25 kW kg−1. These results indicated that the Sb2O3/15 mg rGO composite has the potential promising application as an energy-storage electrode material, as no investigations have been conducted on using Sb2O3/rGO as a supercapacitor electrode.

Synthesis of reduced graphene oxide (rGO)/polyaniline (PANI) composite electrode for energy storage: Aqueous asymmetric supercapacitor

Composite materials have gained significant interest for energy storage applications due to their possible synergistic effects. This work describes the synthesis of reduced graphene oxide (rGO)/polyaniline (PANI) composite thin films using chemical bath deposition (CBD) method. A field-emission scanning electron microscope revealed that PANI spikes coated on rGO sheets in rGO/PANI composite. The electrochemical studies of a rGO/PANI composite electrode showed a specific capacitance (Cs) of 1130F/g Cs at a scan rate of 5 mV/s in 1 M H2SO4 electrolyte. The combined effect of rGO with PANI, a aqueous asymmetric supercapacitor device (ASC) with configuration of rGO/PANI/H2SO4/WO3 produced 97F/g Cs at a 5 mV/s scan rate and retained 82 % capacitance after 5,000 galvanostatic charge–discharge cycles. The ASC achieved a high specific energy of 23 Wh kg−1 at a specific power of 732 W kg−1. The electrochemical properties of rGO/PANI composite indicate a feasible method for creating asymmetric supercapacitors.

Flower-like SnO2 nanorod aggregates modified with Co3O4 nanoparticles grown on reduced graphene oxide(rGO) sheets for xylene sensing

In this paper, the ternary composite of flower-like SnO2 nanorod aggregates modified with Co3O4 nanoparticles grown on rGO sheets were synthesized by a two-step process of water heating and water bath, and characterized by SEM, TEM, XRD, EDS, and XPS. The gas-sensitive performance test results revealed that the 15-rGO/SnO2/Co3O4 sensor exhibited a higher response value (I0/Ia=24.46) to 100 ppm xylene at the optimal working temperature of 175℃. In addition, the sensor could detect 10 ppb xylene, with a low detection limit. The gas-sensitive properties of 15-rGO/SnO2/Co3O4 were significantly improved due to the large specific surface area of rGO flakes and SnO2 slender nanorods, the catalytic action of p-type semiconductor Co3O4 and the existence of p-n-p double heterojunction. Due to the special nanostructure and synergistic effect of SnO2, rGO and Co3O4, the 15-rGO/SnO2/Co3O4 sensor enabled the efficient and selective detection of xylene.

Production and characterizations of silver-doped copper ferrite anchored in RGO surface

The rapid advancements in nanotechnology have spurred the search for more efficient materials across various advanced applications. To this end, this study aimed to synthesize and investigate the structural properties of copper ferrite and mixed copper-silver ferrite anchored onto reduced graphene oxide (rGO) sheets. Samples were synthesized via the hydrothermal method at four different temperature ranges for 6 h at pH 11. The systems were analyzed using Raman spectroscopy, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). XRD analysis revealed changes in the structural parameters of the ferrite, the presence of Fe2O3 and Ag, and confirmed the anchorage of submicron particles onto rGO, along with diversified morphologies. Both Raman spectroscopy and XRD confirmed the reduction of graphene oxide (GO) to rGO.

Alumina fiber/reduced graphene oxide composite films for high-temperature heating and sensing

Reduced graphene oxide (rGO) and its composite films have aroused intense interest in electrical heating and temperature sensing fields, but the working temperature is usually limited because the internal layer-stacked structure is breakable at high temperature. In order to promote structure stability, a series of Al2O3 fiber/rGO composite films were developed. It is found that gaseous products mainly including CO2 and CO during thermal reduction contribute to pores, bulges and intervals in rGO films, while appropriate Al2O3 fiber has an adhesion effect on rGO sheets and tightens them together, in which case defects can hardly form and the layered structure is significantly compacted. Therefore, the degree of stacking order and tensile strength tend to increase, resulting in the improvement of structure stability and decrease of electrical resistivity. However, excess Al2O3 fiber makes the formation of debris and cracks, causing the deterioration of conductivity and mechanical properties. With 20 wt% Al2O3 fiber, the composite films can bear higher heating voltage than pure rGO films and stabilize at 634.65 °C under 36 V, which also keep a good linearity between resistance and temperature from 25 to 600 °C, exhibiting a considerable temperature coefficient of resistance (TCR) with −1.70×10−3 /°C at room temperature.

Optimized Ammonia-Sensing Electrode with CeO2/rGO Nano-Composite Coating Synthesized by Focused Laser Ablation in Liquid.

This study investigated the synthesis of cerium oxide (CeO2) nanoparticles (NPs) and composites with reduced graphene oxide (rGO) for the enhanced electrochemical sensing of ammonia. CeO2 NPs were prepared by the focused laser ablation in liquid (LAL) method, which enabled the production of high-purity, spherical nanoparticles with a uniform dispersion and sizes under 50 nm in a short time. The effects of varying irradiation fluence and time on the nanoparticle size, production yield, and dispersion were systematically studied. The synthesized CeO2 NPs were doped with rGO to form CeO2/rGO composites, which were drop casted to modify the glassy carbon electrodes (GCE). The CeO2/rGO-GCE electrodes exhibited superior electrochemical properties compared with single-component electrodes, which demonstrated the significant potential for ammonia detection, especially at a 4 J/cm2 fluence. The CeO2/rGO composites showed uniformly dispersed CeO2 NPs between the rGO sheets, which enhanced the conductivity, as confirmed by SEM, EDS mapping, and XRD analysis. Cyclic voltammetry data demonstrated superior electrochemical activity of the CeO2/rGO composite electrodes, with the 2rGO/1CeO2 ratio showing the highest current response and sensitivity. The CV response to varying ammonia concentrations exhibited a linear relationship, indicating the electrode's capability for accurate quantification. These findings highlight the effectiveness of focused laser ablation in enhancing nanoparticle synthesis and the promising synergistic effects of CeO2 and rGO in developing high-performance electrochemical sensors.