介孔碳-碳纳米管-硫化铜复合材料对电极的制备及其在量子点敏化太阳能电池中的应用

首先研究了介孔碳(MC)、碳纳米管(CNT)和不同MC/CNT质量比(m_(MC)/m_(CNT))制备的MC-CNT二元复合材料对电极的光电转换效率(PCE),进一步加入预先水热合成的CuS纳米材料,制备出MC-CNT-CuS三元复合材料对电极,同时探讨了CuS添加量和膜厚对对电极PCE的影响。实验结果表明,当m_(MC)/m_(CNT)=3/2时,2种碳材料能最大程度地发挥协同作用,使电池性能最好,PCE达12.69%。再加入0.4 g CuS时PCE可进一步提高,且对电极印刷5层时最优,此时所组装的电池获得的PCE最高(13.18%)。     

Development of a voltammetric method of analysis using praseodymium oxide-carbon nanotubes for the sensitive detection of dopamine in the presence of tramadol,paracetamol and ascorbic acid

A sensitive and selective method of analysis was constructed by the the combination of praseodymium oxide and carbon nanotubes. The charge transfer resistance (Rct) values of 109 in 1 × 10⁻³ M K₃[Fe(CN)₆] and 79 Ω in 5 × 10⁻⁶ M dopamine indicate that Pr₆O₁₁@MWCNTs/GCE enables an excellent electron pathway between electrolyte and electrode. The platform was successfully applied for the determination of dopamine in the presence of tramadol, paracetamol and ascorbic acid. The platform exhibited a remarkable decrease in ▵Ep for DA. A dynamic linear range from 1.2 × 10⁻⁹ M to 1.8 × 10⁻⁵ M was obtained with an LOD of 1.0 × 10⁻¹⁰ M. Such a sensitive and selective method of analysis makes Pr₆O₁₁@MWCNTs/GCE of high interest to observe trace level of DA with good accuracy and precision.     

Self-Assembled Graphene/MWCNT Bilayers as Platinum-Free Counter Electrode in Dye-Sensitized Solar Cells

We describe the preparation and properties of bilayers of graphene- and multi-walled carbon nanotubes (MWCNTs) as an alternative to conventionally used platinum-based counter electrode for dye-sensitized solar cells (DSSC). The counter electrodes were prepared by a simple and easy-to-implement double self-assembly process. The preparation allows for controlling the surface roughness of electrode in a layer-by-layer deposition. Annealing under N₂ atmosphere improves the electrode's conductivity and the catalytic activity of graphene and MWCNTs to reduce the I₃⁻ species within the electrolyte of the DSSC. The performance of different counter-electrodes is compared for ZnO photoanode-based DSSCs. Bilayer electrodes show higher power conversion efficiencies than monolayer graphene electrodes or monolayer MWCNTs electrodes. The bilayer graphene (bottom)/MWCNTs (top) counter electrode-based DSSC exhibits a maximum power conversion efficiency of 4.1 % exceeding the efficiency of a reference DSSC with a thin film platinum counter electrode (efficiency of 3.4 %). In addition, the double self-assembled counter electrodes are mechanically stable, which enables their recycling for DSSCs fabrication without significant loss of the solar cell performance.     

Enhanced Electrocatalytic Performance of a Porous g‐C3N4/Graphene Composite as a Counter Electrode for Dye‐Sensitized Solar Cells

A porous graphitic carbon nitride (g‐C₃N₄)/graphene composite was prepared by a simple hydrothermal method and explored as the counter electrode of dye‐sensitized solar cells (DSCs). The obtained g‐C₃N₄/graphene composite was characterized by XRD, SEM, TEM, FTIR spectroscopy, and X‐ray photoelectron spectroscopy. The results show that incorporating graphene nanosheets into g‐C₃N₄ forms a three‐dimensional architecture with a high surface area, porous structure, efficient electron‐transport network, and fast charge‐transfer kinetics at the g‐C₃N₄/graphene interfaces. These properties result in more electrocatalytic active sites and facilitate electrolyte diffusion and electron transport in the porous framework. As a result, the as‐prepared porous g‐C₃N₄/graphene composite exhibits an excellent electrocatalytic activity. In I^?/I₃^? redox electrolyte, the charge‐transfer resistance of the porous g‐C₃N₄/graphene composite electrode is 1.8 Ω cm², which is much lower than those of individual g‐C₃N₄ (70.1 Ω cm²) and graphene (32.4 Ω cm²) electrodes. This enhanced electrocatalytic performance is beneficial for improving the photovoltaic performance of DSCs. By employing the porous g‐C₃N₄/graphene composite as the counter electrode, the DSC achieves a conversion efficiency of 7.13 %. This efficiency is comparable to 7.37 % for a cell with a platinum counter electrode.     

A Single Drop Fabrication of the Cholesterol Biosensor Based on Synthesized NiFe2O4NPs Dispersed on PDDA‐CNTs

A cholesterol biosensor based on cholesterol oxidase‐poly(diallyldimethylammonium chloride)‐carbon nanotubes‐nickel ferrite nanoparticles (ChOx‐PDDA‐CNTs‐NiFe₂O₄NPs) solution is easily fabricated by using a single dropping step on a glassy carbon electrode (GCE) surface. This technique is an alternative way to reduce complexity, cost and time to produce the biosensor. The uniformly dispersed materials on the electrode surface enhance the catalytic reaction of cholesterol oxidase and electron transfer from the oxidation of hydrogen peroxide in the system. The nickel ferrite nanoparticles were synthesized by co‐precipitation and calcination at various temperatures. These nanoparticles were then characterized using field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and X‐ray diffraction (XRD). The synthesized material calcined at 700 °C was well defined and presented the octahedral metal stretching with cubic NiFe₂O₄NPs phase. In cyclic voltammetric study, the ChOx‐PDDA‐CNTs‐NiFe₂O₄NPs/GCE showed 0.43 s⁻¹ charge transfer rate constant (K _s), 7.79×10⁻⁶ cm² s⁻¹ diffusion coefficient value (D ), 0.13 mm² electroactive surface area (A _e) and 3.58×10⁻⁸ mol cm⁻² surface concentration ( ). This modified electrode exhibits stability in term of percent relative standard deviation (%RSD=0.62 %, n=10), reproducibility (%RSD=0.81, n=10), high sensitivity (25.76 nA per mg L⁻¹ cm⁻²), linearity from 1 to 5,000 mg L⁻¹ (R²=0.998) with a low detection limit (0.50 mg L⁻¹). Its Michaelis‐Menten constant (K _m) was 0.14 mM with 0.92 μA maximum current (I _max) and demonstrated good selectivity without the effects of electroactive species such as ascorbic acid, glucose and uric acid. The cholesterol biosensor was successfully applied to determine cholesterol levels in human blood samples, showing promise due to its simplicity and availability.     

Growth of aligned polypyrrole acicular nanorods and their application as Pt‐free semitransparent counter electrode in dye‐sensitized solar cell

Polypyrrole films on fluorine doped tin oxide (FTO)‐coated glass substrate were prepared in situ by placing FTO/glass substrates where pyrrole was polymerized by methyl orange‐ferric chloride complex. The atomic force microscopy image indicated growth of acicular nanorods of polypyrrole. These films exhibited catalytic activity towards I₃⁻/I⁻ redox couple and have been investigated for counter electrode application in dye‐sensitized solar cell (DSSC). The fabricated DSSC with N719 dye/TiO₂ as photoanode, and PPy/FTO as counter electrode shows ~1.7% efficiency.     

Transparent Metal Selenide Alloy Counter Electrodes for High‐Efficiency Bifacial Dye‐Sensitized Solar Cells

The exploration of cost‐effective and transparent counter electrodes (CEs) is a persistent objective in the development of bifacial dye‐sensitized solar cells (DSSCs). Transparent counter electrodes based on binary‐alloy metal selenides (M‐Se; M=Co, Ni, Cu, Fe, Ru) are now obtained by a mild, solution‐based method and employed in efficient bifacial DSSCs. Owing to superior charge‐transfer ability for the I^?/I₃^? redox couple, electrocatalytic activity toward I₃^? reduction, and optical transparency, the bifacial DSSCs with CEs consisting of a metal selenide alloy yield front and rear efficiencies of 8.30 % and 4.63 % for Co_0.85Se, 7.85 % and 4.37 % for Ni_0.85Se, 6.43 % and 4.24 % for Cu_0.50Se, 7.64 % and 5.05 % for FeSe, and 9.22 % and 5.90 % for Ru_0.33Se in comparison with 6.18 % and 3.56 % for a cell with an electrode based on pristine platinum, respectively. Moreover, fast activity onset, high multiple start/stop capability, and relatively good stability demonstrate that these new electrodes should find applications in solar panels.     

An impedimetric biosensor based on poly(l-lysine)-decorated multiwall carbon nanotubes for the determination of diazinon in water and fruits

A new electrochemical biosensor is developed for the detection of diazinon. For this purpose, a glassy carbon electrode is modified with MWCNTs and poly-l-lysine to immobilize a double-strain DNA (ds-DNA) on the surface of the electrode. In the first step, the interaction of diazinon with ds-DNA is transduced by electrochemical impedance spectroscopy and UV–Vis spectroscopy to monitor the intercalation of diazinon with DNA helix. This interaction leads to reduced interfacial charge-transfer resistance (R_ct). The difference in the R_ct before and after the interaction is considered as a suitable signal for diazinon detection. The proposed biosensor has a low detection limit (0.3 nmol L⁻¹), a wide linear dynamic range (0.001‒100 µmol L⁻¹), and high selectivity for the determination of diazinon. Finally, the performance of the biosensor for detecting of diazinon is verified in real samples such as river water, agricultural wastewater, lettuce juice, and tomato juice.

     

Choline Oxidase Based Composite ZrO2@AuNPs with Cu2O@MnO2 Platform for Signal Enhancing the Choline Biosensors

A novel metal composite material based on zirconium dioxide decorated gold nanoparticles (ZrO₂@AuNPs), copper (I) oxide at manganese (IV) oxide (Cu₂O@MnO₂) and immobilized choline oxidase (ChOx) onto a glassy carbon electrode (GCE) (ChOx/Cu₂O@MnO₂-ZrO₂@AuNPs/GCE) has been developed for enhancing the electro-catalytic property, sensitivity and stability of the amperometric choline biosensor. The ChOx/Cu₂O@MnO₂-ZrO₂@AuNPs/GCE displayed an excellent electrocatalytic response to the oxidation of the byproduct H₂O₂ from the choline catalyzed reaction, which exhibited a charge transfer rate constant (K_s) of 0.97 s⁻¹, a diffusion coefficient value (D) of 4.50×10⁻⁶ cm² s⁻¹, an electroactive surface area (A_e) of 0.97 cm² and a surface concentration (γ) of 0.54×10⁻⁸ mol cm⁻². The modified electrode also provided a wide linear range of choline concentration from 0.5 to 1,000.0 μM with good sensitivity (97.4 μA cm⁻² mM⁻¹) and low detection limit (0.3 μM). The apparent Michaelis-Menten constant was found to be 0.08 mM with I_max of 0.67 μA. This choline biosensor presented high repeatability (%RSD=2.9, n=5), excellent reproducibility (%RSD=2.9, n=5), long time of use (n=28 with %I>50.0 %) and good selectivity without interfering effects from possible electroactive species such as ascorbic acid, aspirin, amoxicillin, caffeine, dopamine, glucose, sucrose and uric acid. This optimal method was successfully applied for choline measurement in prepared human blood samples which demonstrated accurate and excellent reliability in the recovery range from 96.7 to 102.0 %.     

Highly Sensitive in vitro Biosensor for Enterotoxigenic Escherichia coli Detection Based on ssDNA Anchored on PtNPs‐Chitosan Nanocomposite

Detection of Enterotoxigenic Escherichia coli in various biological samples has tremendous importance in human health. In this direction, we have designed a label free electrochemical biosensor for highly selective detection of Escherichia coli through detecting ST gene. The ability of sensor probe to detect ST_G was confirmed using polymerase chain reaction. The biosensor was fabricated based on ST_G specific probes immobilized on platinum nanoparticles chitosan nanocomposite on screen printed carbon electrode, which was characterized by cyclic voltammetry, transmission electron microscopy, and fourier transform infrared spectroscopy. A highly sensitive label free sensing was achieved by analyzing ST_G hybridization using electrochemical impedance spectroscopy (EIS) technique. The EIS analysis showed a significant increase in charge transfer resistance after ST_G interaction with the highly selective ssDNA probe immobilized on the nanocomposite film. The increase in charge transfer resistance was evaluated for varying concentrations of ST_G, which shows a dynamic range between 1.0×10⁻¹² and 1.0×10⁻⁴ with the detection limit of 3.6×10⁻¹⁴ M (RSD<4.5 %). The regeneration of sensor probe was also studied and interference due to non‐target sequences was evaluated to ensure the selectivity of the designed sensor. The practical applicability of sensor probe was also analyzed by detecting the ST_G from the bacteria present in surface water.     

High-performance Pt-NiO nanosheet-based counter electrodes for dye-sensitized solar cells

High-performance counter electrodes for dye-sensitized solar cells (DSSCs) are fabricated with platinum-nickel oxide (Pt-NiO) nanosheets as catalytic materials. Firstly, the Pt-Ni nanosheets are synthesized via galvanic replacement reaction between pre-synthesized Ni nanosheets and an aqueous H₂PtCl₆ solution. Secondly, after thermal treatment in air, the Pt-Ni alloys are turned to Pt-NiO nanosheets. The related data of cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization reveal that Pt-NiO counter electrodes show highly catalytic activity and low charge transfer resistance. The DSSC with Pt-NiO counter electrode exhibits power conversion efficiency (PCE) of 8.40 %, which is lower than that of the DSSC containing commercial available Pt counter electrode (9.15 %) under full sunlight illumination (100 mW cm^?2, AM1.5G). However, owing to the extremely high transparency of Pt-NiO counter electrode, when putting an Ag mirror behind the back side of the DSSC, the reflected light can bring great enhanced PCE (11.27 %).     

Selective Electroanalysis of Ascorbic Acid Using a Nickel Hexacyanoferrate and Poly(3,4‐ethylenedioxythiophene) Hybrid Film Modified Electrode

The mixed‐valent nickel hexacyanoferrate (NiHCF) and poly(3,4‐ethylenedioxythiophene) (PEDOT) hybrid film (NiHCF‐PEDOT) was prepared on a glassy carbon electrode (GCE) by multiple scan cyclic voltammetry. The films were characterized using atomic force microscopy, field emission scanning electron microscopy, energy dispersive spectroscopy, X‐ray diffraction, and electrochemical impedance spectroscopy (AC impedance). The advantages of these films were demonstrated for the detection of ascorbic acid (AA) using cyclic voltammetry and amperometric techniques. The electrocatalytic oxidation of AA at different electrode surfaces, such as the bare GCE, the NiHCF/GCE, and the NiHCF‐PEDOT/GCE modified electrodes, was determined in phosphate buffer solution (pH 7). The AA electrochemical sensor exhibited a linear response from 5×10⁻⁶ to 1.5×10⁻⁴ M (R²=0.9973) and from 1.55×10⁻⁴ to 3×10⁻⁴ M (R²=0.9983), detection limit=1×10⁻⁶ M, with a fast response time (3 s) for AA determination. In addition, the NiHCF‐PEDOT/GCE was advantageous in terms of its simple preparation, specificity, stability and reproducibility.     

High Energy Density Heteroatom (O,N and S) Enriched Activated Carbon for Rational Design of Symmetric Supercapacitors

Carbon-based symmetric supercapacitors (SCs) are known for their high power density and long cyclability, making them an ideal candidate for power sources in new-generation electronic devices. To boost their electrochemical performances, deriving activated carbon doped with heteroatoms such as N, O, and S are highly desirable for increasing the specific capacitance. In this regard, activated carbon (AC) self-doped with heteroatoms is directly derived from bio-waste (lima-bean shell) using different KOH activation processes. The heteroatom-enriched AC synthesized using a pretreated carbon-to-KOH ratio of 1:2 (ONS@AC-2) shows excellent surface morphology with a large surface area of 1508 m² g⁻¹. As an SC electrode material, the presence of heteroatoms (N and S) reduces the interfacial charge-transfer resistance and increases the ion-accessible surface area, which inherently provides additional pseudocapacitance. The ONS@AC-2 electrode attains a maximum specific capacitance (C_sp) of 342 F g⁻¹ at a specific current of 1 Ag⁻¹ in 1 m NaClO₄ electrolyte at the wide potential window of 1.8 V. Moreover, as symmetric SCs the ONS@AC-2 electrode delivers a maximum specific capacitance (C_sc) of 191 F g⁻¹ with a maximum specific energy of 21.48 Wh kg⁻¹ and high specific power of 14 000 W kg⁻¹ and excellent retention of its initial capacitance (98 %) even after 10000 charge/discharge cycles. In addition, a flexible supercapacitor fabricated utilizing ONS@AC-2 electrodes and a LiCl/polyvinyl alcohol (PVA)-based polymer electrolyte shows a maximum C_sc of 119 F g⁻¹ with considerable specific energy and power.     

Chlorophyll a photoelectrochemical cells with different metal electrodes

A photosensitive electrode was prepared by electrodepositing a membrane of chlorophyll a (Chla) on a SnO2 optical transparent electrode,with which and a metal counter electrode a Chla photoelectrochemical cell was formed.Photoinduced current (Ii) and photoinduced voltage (Vi) of the cell were measured.The dependence of Ii on the properties of metal electrodes was obvious,which was illustrated with mechanism of Chla photoelectrical effects Ii in this work was as high as 2×10-5 A·cm-2.     

Spectroelectrochemical and Voltammetric Studies of L‐DOPA

The electrooxidation of L -dopa at GC electrode was studied by in situ UV-vis spectroelectrochemistry (SEC) and cyclic voltammetry. The mechanism of electrooxidation and some reaction parameters were obtained. The results showed that the whole electrooxidation reaction of L -dopa at glassy carbon (GC) electrode was an irreversible electrochemical process followed by a chemical reaction in neutral solution (EC mechanism). The spectroelectrochemical data were treated by the double logarithm method together with nonlinear regression, from which the formal potential E⁰=228 mV, the apparent electron-transfer number of the electrooxidation reaction αn=0.376 (R=0.99, SD=0.26), the standard electrochemical rate constant k⁰=(3.93±0.12)×10⁻4 cm s⁻¹ (SD=1.02×10⁻²), and the formation equilibrium constant of the following chemical reaction k_c=(5.38±0.34)×10⁻¹ s⁻¹ (SD=1.02×10⁻²) were also obtained.     

Influence of copper hexacyanoferrate film thickness on the electrochemical properties of self-assembled 3-mercaptopropyl gold electrode and application as a hydrazine sensor

A copper hexacyanoferrate film was obtained on a modified electrode prepared by self-assembly of 3-mercaptopropyltrimethoxysilane on a gold surface. The film thickness was controlled using a layer-by-layer technique to tune the electrocatalytic properties of the electrode. Two electrodes with different hexacyanoferrate film thicknesses were prepared via three immersions (AuS/CuHCF3) and six immersions (AuS/CuHCF6) of the film in the precursor solutions. Cyclic voltammetry data were obtained to determine the adequate film thickness. Scanning electron microscopy images showed a roughness increase due to the growth of the film thickness at the electrode surface. Electrochemical impedance spectroscopy showed distinct behavior for the two electrodes prepared; while diffusion and charge transfer processes can be observed in both electrodes, an additional capacitive process at intermediary frequencies was observed for the AuS/CuHCF6 electrode. The charge transfer resistance (R _ct) for the AuS/CuHCF3 electrode (19.6 Ω cm²) was lower than for AuS/CuHCF6 (27.9 Ω cm²) due to the hexacyanoferrate film thickness, since the charge transfer process demands the simultaneous diffusion of K⁺ into the surface. Cyclic voltammetry was used to evaluate the application of the AuS/CuHCF3 electrode as an electrochemical sensor, revealing a linear correlation for hydrazine concentrations.     

Electrochemical Oxidation Behavior of Nitrogen Dioxide for Gas Detection Using Boron Doped Diamond Electrodes

The electrochemical oxidation reaction of nitrogen dioxide (NO₂) using boron doped diamond (BDD) electrodes is presented. Cyclic voltammetry of NO₂ in a 0.1 M KClO₄ solution exhibits oxidation peaks at +1.1 V and +1.5 V (vs. Ag/AgCl) which are attributable to oxidation of HONO and NO₂⁻, respectively. Moreover, the pH and scan rate dependences were investigated to study the oxidation mechanism. A linear calibration curve was observed in the concentration range of ∼1 to 5 mM (R²=0.99) with a detection limit of 11.1 ppb (S/B=3) for HONO and 58.6 ppb (S/B=3) for NO₂⁻. In addition, the analytical performance was compared with those using glassy carbon, platinum and stainless steel as the working electrode.     

Adsorptive Stripping Differential Pulse Voltammetric Determination of Risperidone with a Multi‐Walled Carbon Nanotube‐Ionic Liquid Paste Modified Glassy Carbon Electrode

A new composite electrode has been fabricated based on coating multi‐walled carbon nanotubes (MWCNTs) and n‐octylpyridinum hexafluorophosphate (OPPF₆) ionic liquid composite on a glassy carbon (GC) electrode (OPPF₆‐MWCNTs/GCE). This electrode shows very attractive electrochemical performances for electrooxidation of risperidone (RIS) compared to conventional electrodes using carbon and mineral oil, notably improved sensitivity and stability. The oxidation peak potentials in cyclic voltammogram of RIS on the OPPF₆‐MWCNTs/GCE was occurred around 230 mV vs. SCE at Britton–Robinson (B–R) buffer (pH 4.0) at scan rate of 100 mV s^?1. The electrochemical parameters such as diffusion coefficient (D), charge transfer coefficient (α) and the electron transfer rate constant (k/_s) were determined using cyclic voltammetry. Under the optimized conditions, the peak current was linear to risperidone concentration over the concentration range of 10–200 nM with sensitivity of 0.016 μA/nM^?1 using differential pulse voltammetry. The detection limit was 6.54 nM (S/N = 3). The electrode also displayed good selectivity and repeatability. In the presence of clozapine (CLZ) the response of RIS kept almost unchanged. Thus this electrode could find application in the determination of RIS in some real samples. The analytical performance of the OPPF₆‐MWCNTs/GCE was demonstrated for the determination of RIS in human serum and pharmaceutical samples.     

Fe/Cu修饰氮掺杂碳纳米管的构筑及催化性能

通过简单的原位化学合成法结合离子交换法制备了Cu修饰氮掺杂碳（Cu-N-C）和Fe/Cu修饰氮掺杂碳纳米管（Fe/Cu-N-C/CNT）,并系统评估了2种催化剂作为染料敏化太阳能电池（dye-sensitized solar cells,DSSCs）对电极在I₃^-/I^-体系中的电化学特性和光伏性能。采用X射线衍射（XRD）、拉曼（Raman）、X射线光电子能谱（XPS）和场发射扫描电镜（FESEM）对合成的催化剂进行组分和形貌表征。结果表明：纳米管状的Fe/Cu-N-C/CNT的石墨化程度比纳米颗粒状的Cu-N-C更高,更有利于I₃^-还原反应中电荷的传输。光伏性能测试结果表明：基于Fe/Cu-N-C/CNT对电极的DSSCs的光电能量转换效率（power conversion efficiency,PCE）达到7.55%,高于相同测试条件下Cu-N-C（6.99%）和Pt（6.76%）对电极的PCE。50圈连续循环伏安测试结果表明：Fe/Cu-N-C/CNT催化剂具有比Cu-N-C更好的电化学稳定性。     

Preparation, Electrochemical Behavior and Electrocatalytic Activity of a Copper Hexacyanoferrate Modified Ceramic Carbon Electrode

A copper hexacyanoferrate modified ceramic carbon electrode （CuHCF/CCE） had been prepared by two-step sol-gel technique and characterized using electrochemical methods. The resulting modified electrode showed a pair of well-defined surface waves in the potential range of 0.40 to 1.0 V with the formal potential of 0.682 V （vs. SCE） in 0.050 mol·dm^-3 HOAc-NaOAc buffer containing 0.30 mol·dm^-3 KCl. The charge transfer coefficient （a） and charge transfer rate constant （ks） for the modified electrode were calculated. The electrocatalytic activity of this modified electrode to hydrazine was also investigated, and chronoamperometry was exploited to conveniently determine the diffusion coefficient （D） of hydrazine in solution and the catalytic rate constant （kcat）. Finally, hydrazine was determined with amperometry using the resulting modified electrode. The calibration plot for hydrazine determination was linear in 3.0 × 10^-6--7.5 × 10^-4 mol·dm^-3 with the detection limit of 8.0 × 10^-7 molodm^-3. This modified electrode had some advantages over the modified film electrodes constructed by the conventional methods, such as renewable surface, good long-term stability, excellent catalytic activity and short response time to hydrazine.