Impact of different anode materials on electro-Fenton process and tannery wastewater treatment using sequential electro-Fenton and electrocoagulation

The influence of anode materials on the electrochemical treatment of tannery wastewater (TWW) was evaluated using Pt, Ti/RuO₂-IrO₂ (DSA), Ti/SnO₂-Sb, Ti/PbO₂, and Ti/SnO₂-Sb/PbO₂ electrodes. The comparison of the degradation mechanism of these electrodes in the electro-Fenton (EF) treatment was evaluated. The Ti/SnO₂-Sb/PbO₂ anode was efficient, with high electrocatalytic activity, stability, and reproducibility of the degradation results. Further, the study was extended to define the ability of sequential EF and electrocoagulation (EC) processes to clean TWW. The EC treatment was conducted using Al electrodes, and the performance of the combined treatment was evaluated by the removal of chemical oxygen demand (COD), turbidity, total suspended solids (TSS), sulfide, and Cr removal. The role of chlorides and sulfate salts during both treatments was evaluated by monitoring the concentration changes of these anions during the whole treatment using ion chromatography (IC). A sequential 1.5 h EF and 1 h EC treatment were applied to achieve a satisfactory degradation of (81.2 ± 3.9)% COD, >98% Cr, >99% turbidity, TSS, and sulfide removal. Additionally, the combined treatment was found to be more efficient towards the COD removal, achieving about 22.5% higher COD removal consuming almost the same amount of electrical energy.

Preparation of Porous Ti/RuO2-IrO2@Pt, Ti/RuO2-TiO2@Pt and Ti/Y2O3-RuO2-TiO2@Pt Anodes for Efficient Electrocatalytic Decomposition of Tetracycline

Electrocatalytic oxidation (ECO) has attracted attention because of its high efficiency and environmental friendliness in water treatment. The preparation of anodes with high catalytic activity and long service lifetimes is a core part of electrocatalytic oxidation technology. Here, porous Ti/RuO₂-IrO₂@Pt, Ti/RuO₂-TiO₂@Pt, and Ti/Y₂O₃-RuO₂-TiO₂@Pt anodes were fabricated by means of modified micro-emulsion and vacuum impregnation methods with high porosity titanium plates as substrates. The scanning electron microscopy (SEM) images showed that RuO₂-IrO₂@Pt, RuO₂-TiO₂@Pt, and Y₂O₃-RuO₂-TiO₂@Pt nanoparticles were coated on the inner surface of the as-prepared anodes to form the active layer. Electrochemical analysis revealed that the high porosity substrate could result in a large electrochemically active area, and a long service life (60 h at 2 A cm^-2 current density, 1 mol L^-1 H₂SO₄ as the electrolyte, and 40 °C). The degradation experiments conducted on tetracycline hydrochloride (TC) showed that the porous Ti/Y₂O₃-RuO₂-TiO₂@Pt had the highest degradation efficiency for tetracycline, reaching 100% removal in 10 min with the lowest energy consumption of 167 kWh kg^-1 TOC. The reaction was consistent with the pseudo-primary kinetics results with a k value of 0.5480 mol L^-1 s^-1, which was 16 times higher than that of the commercial Ti/RuO₂-IrO₂ electrode. The fluorospectrophotometry studies verified that the degradation and mineralization of tetracycline were mainly ascribed to the •OH generated in the electrocatalytic oxidation process. This study thus presents a series of alternative anodes for future industrial wastewater treatment.

Characterization of electrodes modified with sludge-derived biochar and its performance of electrocatalytic oxidation of azo dyes

Pyrolysis of waste sludge in sewage treatment can achieve a substantial reduction in solid waste and obtain sludge-based biochars with multiple functions. However, the electrochemical properties of sludge-derived biochar as electrode modification material and the electrocatalytic ability of biochar-modified electrodes are still unclear. In this study, sludge-based biochars were prepared at various pyrolysis temperatures (400 °C, 500 °C, 600 °C, 700 °C, and 800 °C) and then were cast on glassy carbon electrodes to fabricate composite biochar-electrodes (GC400, GC500, GC600, GC700, and GC800). The results of elemental analysis and Raman spectra showed that sludge-based biochar prepared at higher temperatures exhibited higher aromaticity and degree of defect structures. And the results of cyclic voltammetry and electrochemical impedance spectra confirmed that biochar-modified electrodes prepared at higher temperatures (>600 °C) possessed better electrocatalytic activity and electrochemical stability, and their higher oxygen evolution potential than control test could improve the electrocatalytic efficiency. In the electrocatalytic oxidation of methyl orange, the removal rate with GC800 was the highest, reaching 94.49% within 240 min, and the removal rates with other composite electrodes were 90.61% (GC700) > 86.96% (GC600) > 80.32% (GC). The free radical quenching experiment revealed that the electrocatalytic degradation of methyl orange mainly depended on the indirect oxidation of hydroxyl radicals generated by electrocatalysis, accounting for 81.3% of the removal rate. The biochar-modified electrode not only greatly improved the electrocatalytic ability of the electrode for the degradation of azo dyes, but also achieved the recycling application of products after pyrolysis of sludge waste.

Electrooxidation of per- and polyfluoroalkyl substances in chloride-containing water on surface-fluorinated Ti4O7 anodes: Mitigation and elimination of chlorate and perchlorate formation

Electrooxidation (EO) has been shown effective in degrading per- and polyfluoroalkyl substances (PFASs) in water, but concurrent formation of chlorate and perchlorate in the presence of chloride is of concern due to their toxicity. This study examined EO treatment of three representative PFASs, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonate (6:2 FTS), in chloride-containing solutions on pristine and surface-fluorinated Ti₄O₇ anodes having different percentage of surface fluorination. The experiment results indicate that surface fluorination of Ti₄O₇ anodes slightly inhibited PFAS degradation, while significantly decreased the formation of chlorate and perchlorate. Further studies with spectroscopic and electrochemical characterizations and density functional theory (DFT) computation reveal the mechanisms of the impact on EO performance by anode fluorination. In particular, chlorate and perchlorate formation were fully inhibited when fluorinated Ti₄O₇ anode was used in reactive electrochemical membrane (REM) under a proper anodic potential range (<3.0 V vs Standard Hydrogen Electrode), resulting from slower intermediate reaction steps and short residence time of the REM system. The results of this study provide a basis for design and optimization of modified Ti₄O₇ anodes for efficient EO treatment of PFAS while limiting chlorate and perchlorate formation.

Recent advances in electrocatalytic membrane for the removal of micropollutants from water and wastewater

The increasing occurrence of micropollutants in water and wastewater threatens human health and ecological security. Electrocatalytic membrane (EM), a new hybrid water treatment platform that integrates membrane separation with electrochemical technologies, has attracted extensive attention in the removal of micropollutants from water and wastewater in the past decade. Here, we systematically review the recent advances of EM for micropollutant removal from water and wastewater. The mechanisms of the EM for micropollutant removal are first introduced. Afterwards, the related membrane materials and operating conditions of the EM are summarized and analyzed. Lastly, the challenges and future prospects of the EM in research and applications are also discussed, aiming at a more efficient removal of micropollutants from water and wastewater.

Research trends in the development of anodes for electrochemical oxidation of wastewater

The review focuses on the recent development in anode materials and their synthesis approach, focusing on their compatibility for treating actual industrial wastewater, improving selectivity, electrocatalytic activity, stability at higher concentration, and thereby reducing the mineralization cost for organic pollutant degradation. The advancement in sol–gel technique, including the Pechini method, is discussed in the first section. A separate discussion related to the selection of the electrodeposition method and its deciding parameters is also included. Furthermore, the effect of using advanced heating approaches, including microwave and laser deposition synthesis, is also discussed. Next, a separate discussion is provided on using different types of anode materials and their effect on active •OH radical generation, activity, and electrode stability in direct and indirect oxidation and future aspects. The effect of using different synthesis approaches, additives, and doping is discussed separately for each anode. Graphene, carbon nanotubes (CNTs), and metal doping enhance the number of active sites, electrochemical activity, and mineralization current efficiency (MCE) of the anode. While, microwave or laser heating approaches were proved to be an effective, cheaper, and fast alternative to conventional heating. The electrodeposition and nonaqueous solvent synthesis were convenient and environment-friendly techniques for conductive metallic and polymeric film deposition.

Application of lead oxide electrodes in wastewater treatment: A review

Electrochemical oxidation (EO) based on hydroxyl radicals (·OH) generated on lead dioxide has become a typical advanced oxidation process (AOP). Titanium-based lead dioxide electrodes (PbO₂/Ti) play an increasingly important role in EO. To further improve the efficiency, the structure and properties of the lead dioxide active surface layer can be modified by doping transition metals, rare earth metals, nonmetals, etc. Here, we compare the common preparation methods of lead dioxide. The EO performance of lead dioxide in wastewater containing dyes, pesticides, drugs, landfill leachate, coal, petrochemicals, etc., is discussed along with their suitable operating conditions. Finally, the factors influencing the contaminant removal kinetics on lead dioxide are systematically analysed.

Efficient degradation of polyacrylamide using a 3-dimensional ultra-thin SnO2-Sb coated electrode

Polyacrylamide (PAM) is widely used in polymer flooding processes to increase oil recovery while the byproduct of PAM-containing wastewater is a serious environmental issue. In this study, electrochemical oxidation process (EAOP) was applied for treating PAM wastewater using a new type of 3-dimensional ultra-thin SnO₂-Sb electrode. Nano-sized catalysts were evenly dispersed both on the surface and inside of a porous Ti filter forming nano-thickness catalytic layer that enhances the utilization and bonding of catalysts. This porous Ti electrode showed 20% improved OH· production and 16.3 times increased accelerated service life than the planar Ti electrode. Using this electrode to treat 100 mg L^-1 PAM, the TOC removal efficiency reached over 99% within 3 h under current density of 20 mA cm^-2. The EAOP could fastly break the long-chain PAM molecules into small molecular intermediates. With the porous electrode treating 5 g L^-1 PAM under current density of 30 mA cm^-2, EAOP reduced 94.2% of average molecular weight in 1 h and 92.0% of solution viscosity in 0.5 h. Moreover, the biodegradability of PAM solution was significantly improved as the solution BOD₅/COD ratio raised from 0.05 to 0.41 after 4 h treatment. The degradation pathway of PAM was also investigated.

Electrocatalytic oxidation of ciprofloxacin by Co-Ce-Zr/γ-Al2O3 three-dimensional particle electrode

In this work, Co-Ce-Zr/γ-Al₂O3₃ particle electrodes were prepared for the efficient degradation of ciprofloxacin (CIP). Co-Ce-Zr/γ-Al₂O₃ particle electrodes were analyzed with a scanning electron microscope (SEM), X-Ray Diffraction (XRD), X-Ray Fluorescence Spectrometer (XRF), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). According to the results, significant amounts of Co₃O₄, CeO₂, and ZrO₂ were formed on the Co-Ce-Zr/γ-Al₂O₃ particle electrodes. It was shown that when the conditions of the reaction system were at pH=6, conductivity of 4 ms/cm, current of 0.2 A, initial pollutant concentration of 100 mg/L, and material dosage of 15 g, CIP could be completely degraded within 40 min, and the energy consumed in the reaction was 41.3 kWh/kg CIP. The rate of total organic carbon (TOC) removal by Co-Ce-Zr/γ-Al₂O₃ particle electrodes was recorded to be approximately 52.6%. Using a response surface methodology, we explored the optimal operating conditions. At the same time, we also explored the influence of inorganic anions in water and actual water medium on the rate of CIP removal. In addition, the ESR data proved that the main active substance in the reaction system was ·OH. The degradation intermediates were investigated, and the possible mechanism was proposed. Thus, this research provided a new solution for the treatment of antibiotic-containing wastewater.

Electrocatalytic degradation of diuron herbicide using three-dimensional carbon felt/β-PbO2 anode as a highly porous electrode: Influencing factors and degradation mechanisms

Traditional planar PbO₂ anodes have been used extensively for the electrocatalytic degradation process. However, by using porous PbO₂ anodes that have a three-dimensional architecture, the efficiency of the process can be significantly upgraded. In the current study, carbon felt (CF) with a highly porous structure and a conventional planar graphite sheet (G) were used as electrode substrate for PbO₂ anodes. Both CF/β-PbO₂ and G/β-PbO₂ anodes were prepared by the anodic deposition method. The main properties of the electrodes were characterized by XRD, EDX-mapping, FESEM, and BET-BJH techniques. The electrocatalytic degradation of diuron using three-dimensional porous CF/β-PbO₂ anode was modeled and optimized by a rotatable central composite design. After optimizing the process, the ability of porous CF/β-PbO₂ and planar G/β-PbO₂ anodes to degrade and mineralize diuron was compared. The electrocatalytic degradation of the diuron was well described by a quadratic model (R² > 0.99). Under optimal conditions, the kinetics of diuron removal using CF/β-PbO₂ anode was 3 times faster than the G/β-PbO₂ anode. The energy consumed for the complete mineralization of diuron using CF/β-PbO₂ anode was 2077 kWh kg^-1 TOC. However, the G/β-PbO₂ anode removed only 65% of the TOC by consuming 54% more energy. The CF/β-PbO₂ had more stability (115 vs. 91 h), larger surface area (1.6287 vs. 0.8565 m² g^-1), and higher oxygen evolution potential (1.89 vs. 1.84 V) compared to the G/β-PbO₂. In the proposed pathways for diuron degradation, the aromatic ring and groups of carbonyl, dimethyl urea, and amide were the main targets for HO^• radical attacks.

PbO2 electrode modified by graphene oxide to boost electrodegradation of 4-hydroxybenzophenone

4-Hydroxybenzophenone (4-OH-BP), a highly toxic and widely used pharmaceutical and personal care products (PPCPs), has been obtained growing concern recently. Electrochemical anodic oxidation technology has been confirmed efficient in eliminating organics from aqueous solution. In this work, we constructed two novel PbO₂ electrodes by modifying the middle or active layer with graphene oxide (GO) to degrade aquatic 4-OH-BP. Compared with the pristine PbO₂ electrode, the modification by GO could enhance the anchor of the active layer (PbO₂ particles) onto the middle layer and improve the isolation of the titanium matrix from the active layer and solution. Therefore, we might obtain the better performance of PbO₂ electrodes after modification. Under the experimental conditions optimized by the Box-Behnken design model, as we expected, two novel electrodes (with modified middle layer: 99.85%; with modified active layer: 100%) outperformed the pristine electrode (95.46%) for 4-OH-BP degradation. We proposed the catalytic mechanism of GO-modified electrodes for 4-OH-BP and the degradation pathway of 4-OH-BP and evaluated the toxicity of intermediates based on the quantitative structure-activity relationship model. Furthermore, two GO-modified PbO₂ electrodes consumed less energy than commercial boron-doped diamond electrode, reflecting the prominent practicability of GO-modified PbO₂ electrode.

PbO2 modified with TiO2-NTs composite materials with enhanced OER electrocatalytic activity for Zn electrowinning

The high oxygen evolution overpotential of the Pb-Ag anode is one of the main reasons for the high energy consumption in Zn electrowinning. PbO2, owing to its high conductivity, good corrosion resistance and low cost, is widely used as an excellent coating material. In present research, a novel composite Ti/TiO2-NTs/PbO2 material was synthesized through a facile anodization, annealing, electrochemical reduction and galvanostatic deposition. The surface morphology, internal structure and the mechanisms of TiO2-NTs enhancing electrochemical performance were discussed. The results show that the self-organized high aspect ratio TiO2-NTs with diameter of ∼120 nm and length of ∼8 μm were obtained on Ti substrate. The Ti/TiO2-NTs/PbO2 composite material exhibits excellent oxygen evolution performance and good stability in Zn electrowinning simulation solution (50 g L-1 Zn2+, 150 g L-1 H2SO4) at 35 °C. Its oxygen evolution overpotential is only 630 mV under current density 50 mA cm-2, which is 332 m lower than that of Pb-0.76 wt% Ag (η = 962 mV) and only increases 22 mV after 5000 cycles of CV scanning. Its outstanding electrochemical performance is mainly ascribed to the introduction of TiO2-NTs in Pb(CH3COO)2 media since it refines the crystal grains, increases the electrochemical surface area, greatly reduces the charge transfer resistance (25.4 Ω cm2 to 2.337 Ω cm2) and enhances corrosion resistance. Therefore, the Ti/TiO2-NTs/PbO2 material prepared in Pb(CH3COO)2 medium may be an ideal anode for Zn electrowinning.

β-FeOOH self-supporting electrode for efficient electrochemical anodic oxidation process

In this work, β-FeOOH was synthesized and grown on carbon paper with the assistance of dopamine (PDA) via a facile hydrothermal method, producing β-FeOOH self-supporting electrode eventually. Electrochemical anodic oxidation performance to methyl orange (MO) solution using β-FeOOH anode was investigated and the major influencing factors such as current density, initial pH value and initial MO concentration on MO degradation efficiency were further explored. Experimental results suggested that 99.4% degradation rate of MO could be achieved only after 25 min electrolysis, its pseudo first-order reaction kinetic constant was 11.3 ⅹ 10^-2 min^-1 and the COD removal ratio was 37.3% after 120 min electrolysis under optimized conditions: current density was 10 mA cm^-2, initial pH value was 3 and initial MO concentration was 10 mg L^-1. At the same time, β-FeOOH electrode also exhibited a high cycling stability and the MO removal ratio was still keeping at 84.9% after eight cycles. Moreover, this electrode showed efficient decomposition performance to multiple simulated pollutants, indicating the well potential practical application values of β-FeOOH electrode. At last, the proposed degradation mechanism of MO was evaluated according to the analyzing results of UV-vis and HPLC-MS to MO solution under different degradation durations.

Membrane Separation Coupled with Electrochemical Advanced Oxidation Processes for Organic Wastewater Treatment: A Short Review

Research on the coupling of membrane separation (MS) and electrochemical advanced oxidation processes (EAOPs) has been a hot area in water pollution control for decades. This coupling aims to greatly improve water quality and focuses on the challenges in practical application to provide a promising solution to water shortage problems. This article provides a summary of the coupling configurations of MS and EAOPs, including two-stage and one-pot processes. The two-stage process is a combination of MS and EAOPs where one process acts as a pretreatment for the other. Membrane fouling is reduced when setting EAOPs before MS, while mass transfer is promoted when placing EAOPs after MS. A one-pot process is a kind of integration of two technologies. The anode or cathode of the EAOPs is fabricated from porous materials to function as a membrane electrode; thus, pollutants are concurrently separated and degraded. The advantages of enhanced mass transfer and the enlarged electroactive area suggest that this process has excellent performance at a low current input, leading to much lower energy consumption. The reported conclusions illustrate that the coupling of MS and EAOPs is highly applicable and may be widely employed in wastewater treatment in the future.

Fabrication of Co/Pr co-doped Ti/PbO2 anode for efficiently electrocatalytic degradation of β-naphthoxyacetic acid

The existence of β-naphthoxyacetic acid (BNOA) pesticide in water system has aroused serious environmental problem because of its potential toxicity for humans and organisms. Therefore, exploiting an efficient method without secondary pollution is extremely urgent. Herein, a promising Ti/PbO₂-Co-Pr composite electrode has been successfully fabricated through simple one-step electrodeposition for efficiently electrocatalytic degradation of BNOA. Compared with Ti/PbO₂, Ti/PbO₂-Co and Ti/PbO₂-Pr electrodes, Ti/PbO₂-Co-Pr electrode with smaller pyramidal particles possesses higher oxygen evolution potential, excellent electrochemical stability and outstanding electrocatalytic activity. The optimal degradation condition is assessed by major parameters including temperature, initial pH, current density and Na₂SO₄ concentration. The degradation efficiency and chemical oxygen demand removal efficiency of BNOA reach up to 94.6% and 84.6%, respectively, under optimal condition (temperature 35 °C, initial pH 5, current density 12 mA cm^-2, Na₂SO₄ concentration 8.0 g L^-1 and electrolysis time 3 h). Furthermore, Ti/PbO₂-Co-Pr electrode presents economic energy consumption and superior repeatability. Finally, the possible degradation mechanism of BNOA is put forward according to the main intermediate products identified by liquid chromatography-mass spectrometer. The present research paves a new path to degrade BNOA pesticide wastewater with Ti/PbO₂-Co-Pr electrode.

Preparation and Characterization of Porous Ti/SnO2–Sb2O3/PbO2 Electrodes for the Removal of Chloride Ions in Water

Porous Ti/SnO2–Sb2O3/PbO2 electrodes for electrocatalytic oxidation of chloride ions were studied by exploring the effects of different operating conditions, including pore size, initial concentration, current density, initial pH, electrode plate spacing, and the number of cycles. In addition, a physicochemical characterization and an electrochemical characterization of the porous Ti/SnO2–Sb2O3/PbO2 electrodes were performed. The results showed that Ti/SnO2–Sb2O3/PbO2 electrodes with 150 µm pore size had the best removal effect on chloride ions with removal ratios amounting up to 98.5% when the initial concentration was 10 g L−1, the current density 125 mA cm−2, the initial pH = 9, and the electrode plate spacing 0.5 cm. The results, moreover, showed that the oxygen evolution potential of 150 µm porous Ti/SnO2-Sb2O3/PbO2 electrodes was highest, which minimized side reactions involving oxygen formation and which increased the removal effect of chloride ions.

Electrochemical degradation of antibiotic levofloxacin by PbO2 electrode: Kinetics, energy demands and reaction pathways

In this work, the electrochemical degradation of antibiotic levofloxacin (LFX) has been studied using a novel rare earth La, Y co-doped PbO₂ electrode. The effect of applied current density, pH value and initial LFX concentration on the degradation performance were systematically evaluated. The results demonstrated that electrochemical oxidation of LFX over the La-Y-PbO₂ electrode was highly effective and the reaction followed an apparent first-order kinetic model. Considering the degradation efficiency and energy efficiency, the relative optimal conditions are identified as current density 30 mA cm^-2, pH 3 and initial LFX concentration 800 mg L^-1. According to the identified products, a reaction mechanism has been proposed and the products were further oxidized to CO₂, H₂O, NH₄⁺, NO₃^- and F^-. A total of four aromatic intermediate products of LFX degradation were identified and the different structural changes to the LFX molecule included pepiperazinyl hydroxylation, decarboxylation and defluorination.

Challenges and prospects of advanced oxidation water treatment processes using catalytic nanomaterials

Centralized water treatment has dominated in developed urban areas over the past century, although increasing challenges with this model demand a shift to a more decentralized approach wherein advanced oxidation processes (AOPs) can be appealing treatment options. Efforts to overcome the fundamental obstacles that have thus far limited the practical use of traditional AOPs, such as reducing their chemical and energy input demands, target the utilization of heterogeneous catalysts. Specifically, recent advances in nanotechnology have stimulated extensive research investigating engineered nanomaterial (ENM) applications to AOPs. In this Perspective, we critically evaluate previously studied ENM catalysts and the next-generation treatment technologies they seek to enable. Opportunities for improvement exist at the intersection of materials science and treatment process engineering, as future research should aim to enhance catalyst properties while considering the unique roadblocks to practical ENM implementation in water treatment.

Pesticide tailwater deeply treated by tubular porous electrode reactor (TPER): Purpose for discharging and cost saving

Pesticide tailwater often contains residual and toxic contaminants of triazole fungicides (TFs) due to their poor biodegradability which will do great harm to local aquatic systems. For this case, a novel electrochemical reactor (TPER) equipped a tubular porous RuO₂-Sb₂O₅-SnO₂ electrode was assembled and then employed to deeply treat pesticide tailwater. Characterizations of the electrode studied by SEM, EDS and XRD analysis indicated that it owns a porous structure and a compact and crack-free surface. Influence of the porous structure on electrochemical property was examined by cyclic voltammetry and normal pulse voltammetry. The results indicated that porous structure can not only enlarge electrochemical active area but also increase mass transfer efficiency by 5.7-fold in flow-through mode compared with batch mode. Furthermore, the optimal operating conditions of TPER were flow rate of 250 mL min^-1 and current density of 4 mA cm^-2. After 1.5 h treatment under these conditions, Tz, TC and PPC were removed by 98.9%, 99.0% and 98.4% respectively, while 81.9% of COD was also removed. Additionally, the microbial content was dropped to 0 CFU mL^-1 and fecal coliform was lower than 2 MPN (100 mL)^-1. All results demonstrated that the treated tailwater has met the Class 1 of National Discharge Standard of China. Especially, operating cost of TPER was only $ 0.33 per ton. The excellent performance together with the low cost indicated that TPER is a promising option for depth treatment of industrial tailwater.

Nanostructured 3D-porous graphene hydrogel based Ti/Sb-SnO2-Gr electrode with enhanced electrocatalytic activity

Nanostructured highly porous 3D-Ti/Sb-SnO₂-Gr electrode, based on 3D porous graphene hydrogel was fabricated via a fast-evaporation technique through layer by layer (LBL) deposition. The 3D pores are uniformly distributed on the high fidelity of substrate with pore sizes of 7-12 nm, as confirmed by SEM analysis. Compared to Ti/Sb-SnO₂ electrode, the fabricated 3D porous electrode possesses high oxygen evolution potential (2.40 V), smaller charge transfer resistance (29.40 Ω cm^-2), higher porosity (0.90), enhanced roughness factor (181), and larger voltammetric charge value (57.4 mC cm^-2). Electrocatalytic oxidation of Rhodamine B (RhB) was employed to evaluate the efficiency of the fabricated 3D-Ti/Sb-SnO₂-Gr anode. The results show that the electrochemical reaction follows pseudo first order kinetics with rate constant (k) value of 4.93 × 10^-2 min^-1, which is about 3.91 times higher compared to flat Ti/Sb-SnO₂. The fabricated electrode demonstrates better stability and low specific energy consumption signifying its potential usage in electrocatalysis.

Fabrication and characterization of a novel PbO2 electrode with a CNT interlayer

A novel PbO₂ electrode (marked as CNT–PbO₂) with a carbon nanotube (CNT) interlayer was prepared by electrophoretic deposition and electro-deposition.

Preparation and characterization of a novel porous Ti/SnO2–Sb2O3–CNT/PbO2 electrode for the anodic oxidation of phenol wastewater

Porous Ti/SnO₂–Sb₂O₃–CNT/PbO₂ electrodes were successfully fabricated using a thermal decomposition technique and electro-deposition technologies.