Electrocatalyst For Oxidation Research Articles

Advances in Phosphorus-Based Catalysts for Urea Electrooxidation: A Pathway to Sustainable Waste to Energy Conversion Through Electrocatalysis

The electrocatalytic oxidation of urea has gained significant attention as a promising pathway for sustainable energy conversion and wastewater treatment that could address the dual goals of waste remediation and renewable energy generation. Phosphorous function groups-based catalysts have been introduced as potential electrode materials for enhancing the urea electrocatalytic oxidation reaction (UEOR) due to their unique structural properties, high stability, and tunable electronic characteristics. This review presents recent advancements in phosphorous-based catalysts (phosphates/phosphides) for UEOR. It highlights the development of novel phosphorous materials, synthesis approaches, and electrocatalytic insights into urea electrooxidation on phosphorous-based materials surfaces. Key topics include the role of different metal phosphates, surface modifications, and compositional optimizations to improve electrocatalytic efficiency and durability. Through a critical evaluation of current research trends and technological progress, this review underscores the potential of phosphate-based catalysts as environmentally friendly and efficient alternatives for sustainable waste-to-energy conversion via UEOR. The review concludes with a perspective on future directions for optimizing phosphate catalysts, scaling up practical applications, and integrating UEOR systems into renewable energy infrastructures.

Orbital Coupling of Dual-Atom Sites Boosts Electrocatalytic NO Oxidation and Dynamic Intracellular Response.

In situ measurement of nitric oxide (NO) in living tissue and single cells is highly important for achieving a profound comprehension of cellular functionalities and facilitating the precise diagnosis of critical diseases; however, the progress is greatly hindered by the weak affinity of ultratrace concentration NO in cellular environment toward electrocatalysts. Herein, a new strategy is reported for precisely constructing orbital coupled dual-atomic sites to enhance the affinity between the metal atomic sites and NO on a class of N-doped hollow carbon matrix dual-atomic sites Co─Ni (Co1Ni1-NC) for greatly boosting electrocatalytic NO performance. The as-synthesized Co1Ni1-NC demonstrates a substantially higher current density than Ni1-NC and Co1-NC, coupled with exceptional stability with a negligible degradation rate of 0.6 µA·cm-2·h-1, which is the best among the state-of-the-art electrocatalysts for NO oxidation. Experimental and theoretical investigations collectively reveal that the pivotal role of d-d orbit coupling between Co and Ni sites enables Ni to acquire additional electrons, leading to the occupation of Ni's 3dxy/yz within the 2π orbitals of NO, thus weakening the N≡O triple bond and concurrently accelerating NO adsorption kinetics. It is demonstrated that Co1Ni1-NC-coated nanoelectrode can achieve the in situ sensing of NO in living organs and single cells.

Pyrenetetrasulfonic Acid Tetrasodium Salt‐Modified CoFe Layered Double Hydroxide Enables Stable Alkaline Seawater Oxidation

AbstractSeawater electrolysis is deemed a green and promising technology for producing hydrogen in coastal areas. Nevertheless, ample chloride ions (Cl–) in seawater can corrode anode, especially at ampere‐level current densities (j), which represents a significant impediment to the seawater‐to‐H2 system. In this study, we present a CoFe layered double hydroxide nanoneedle array modified with 1,3,6,8‐pyrenetetrasulfonic acid tetrasodium salt (PTS) on Ni foam (CoFe LDH@CoFe‐PTS/NF) as a highly efficient electrocatalyst for seawater oxidation. It reveals that PTS with a large negative charge density can effectively repel Cl– and keep active sites working stably during alkaline seawater oxidation. Thus, CoFe LDH@CoFe‐PTS/NF demonstrates excellent OER performance and can achieve j of 500 and 1000 mA cm−2 at low overpotentials (η) of 333 and 364 mV. Moreover, it maintains a stable and continuous electrolysis for 500 h with minimal amounts of active chlorine generation.

Cascading Water Activation and Interfacial Lattice Oxygen over Nanocluster CuOx-Modified MnO2 for Electrocatalytic Propylene Oxidation.

Direct electrooxidation of propylene using water-oxidation intermediates represents a promising route for propylene glycol production. Unfortunately, this economic and environmentally friendly process suffers from low yield and poor Faradaic efficiency resulting from the mismatched oxidative capacity of reactive oxygen species and pronounced side reactions. Herein, we developed an earth-abundant metal-based nanocluster CuOx-modified MnO2 catalyst for the efficient electrooxidation of propylene into propylene glycol, achieving a remarkable production rate of 63.0 g/m2/h and 95 % Faradaic efficiency at 1.3 V vs. Ag/AgCl. Mechanistic studies revealed that the oxygen vacancy-mediated water activation on CuOx-MnO2 in synergy with the activated interfacial lattice oxygen drove the propylene oxidation to a novel *OOH pathway rather than the traditional *OH route. Additionally, the interfacial interactions intensified the propylene adsorption and polarization for its activation. This work offers new insights into the mechanism of electrocatalytic propylene oxidation and presents great opportunities for the synthesis of commercial chemicals based on earth-abundant metal catalysts and renewable electricity-driven route.

Cascading Water Activation and Interfacial Lattice Oxygen over Nanocluster CuOx‐modified MnO2 for Electrocatalytic Propylene Oxidation

Direct electrooxidation of propylene using water‐oxidation intermediates represents a promising route for propylene glycol production. Unfortunately, this economic and environmentally friendly process suffers from low yield and poor Faradaic efficiency resulting from the mismatched oxidative capacity of reactive oxygen species and pronounced side reactions. Herein, we developed an earth‐abundant metal‐based nanocluster CuOx‐modified MnO2 catalyst for the efficient electrooxidation of propylene into propylene glycol, achieving a remarkable production rate of 63.0 g/m2/h and 95% Faradaic efficiency at 1.3 V vs. Ag/AgCl. Mechanistic studies revealed that the oxygen vacancy‐mediated water activation on CuOx‐MnO2 in synergy with the activated interfacial lattice oxygen drove the propylene oxidation to a novel *OOH pathway rather than the traditional *OH route. Additionally, the interfacial interactions intensified the propylene adsorption and polarization for its activation. This work offers new insights into the mechanism of electrocatalytic propylene oxidation and presents great opportunities for the synthesis of commercial chemicals based on earth‐abundant metal catalysts and renewable electricity‐driven route.

Integrating Interactive Ir Atoms into Titanium Oxide Lattice for Proton Exchange Membrane Electrolysis.

Iridium (Ir)-based oxide is the state-of-the-art electrocatalyst for acidic water oxidation, yet it is restricted to a few Ir-O octahedral packing modes with limited structural flexibility. Herein, the geometric structure diversification of Ir is achieved by integrating spatially correlated Ir atoms into the surface lattice of TiO2 and its booting effect on oxygen evolution reaction (OER) is investigated. Notably, the resultant i-Ir/TiO2 catalyst exhibits much higher electrocatalytic activity, with an overpotential of 240 mV at 10 mA cm-2 and excellent stability of 315 h at 100 mA cm-2 in acidic electrolyte. Both experimental and theoretical findings reveal that flexible Ir─O─Ir coordination with varied geometric structure plays a crucial role in enhancing OER activity, which optimize the intermediate adsorption by adjusting the d-band center of active Ir sites. Operando characterizations demonstrate that the interactive Ir─O─Ir units can suppress over-oxidation of Ir, effectively widening the stable region of Ir species during the catalytic process. The proton exchange membrane (PEM) electrolyzer, equipped with i-Ir/TiO2 as an anode, gives a low driving voltage of 1.63 V at 2 A cm-2 and maintains stable performance for over 440 h. This work presents a general strategy to eliminate the inherent geometric limitations of IrOx species, thereby inspiring further development of advanced catalyst designs.

Understanding the electrocatalytic role of magnesium doped bismuth copper titanate (BCTO) in oxygen evolution reaction

Designing high-efficiency electrocatalysts for water oxidation has become increasingly important in the catalysis field owing to its implications for renewable energy production and storage. The production of hydrogen (H2) from water is hampered by the very sluggish kinetics of the water-splitting process. Enhancement of effective oxygen evolution reaction (OER) electrocatalysts is also required to understand the primary barrier to OER. This article investigates the electrochemical activity of magnesium-doped bismuth copper titanate (Mg-BCTO) as an efficient catalyst for the OER in water electrolysis, a critical step in hydrogen production for sustainable energy. The synthesized materials, including various stoichiometries of Mg-doped BCTO, undergo thorough physical and electrochemical characterization using XRD, FT-IR, Raman, SEM, TEM, XPS, CV, EIS, and Tafel polarization analyses. Remarkably, Mg0.1 doped BCTO demonstrates superior performance, achieving a current density of 10 mA cm−2 at a very low overpotential (η10) of 265 mV and with a Tafel slope of 92 mV dec−1. This finding not only highlights the electrocatalytic efficiency of Mg doped BCTO but also positions it as a promising model for the development of highly active and stable water oxidizing catalysts, contributing to the advancement of clean energy technologies.

Atomically engineered interfaces inducing bridging oxygen-mediated deprotonation for enhanced oxygen evolution in acidic conditions

The development of efficient and stable electrocatalysts for water oxidation in acidic media is vital for the commercialization of the proton exchange membrane electrolyzers. In this work, we successfully construct Ru–O–Ir atomic interfaces for acidic oxygen evolution reaction (OER). The catalysts achieve overpotentials as low as 167, 300, and 390 mV at 10, 500, and 1500 mA cm−2 in 0.5 M H2SO4, respectively, with the electrocatalyst showing robust stability for >1000 h of operation at 10 mA cm−2 and negligible degradation after 200,000 cyclic voltammetry cycles. Operando spectroelectrochemical measurements together with theoretical investigations reveal that the OER pathway over the Ru–O–Ir active site is near-optimal, where the bridging oxygen site of Ir–OBRI serves as the proton acceptor to accelerate proton transfer on an adjacent Ru centre, breaking the typical adsorption-dissociation linear scaling relationship on a single Ru site and thus enhancing OER activity. Here, we show that rational design of multiple active sites can break the activity/stability trade-off commonly encountered for OER catalysts, offering good approaches towards high-performance acidic OER catalysts.

Activating Lattice Oxygen by Electrochemical De-Lithiation for Efficient Benzyl Alcohol Oxidation.

Electrocatalytic benzyl alcohol oxidation reaction (EBOR) is a feasible way to produce high-value-added benzaldehyde and benzoic acid. However, the performance of catalyst usually suffers from the high energy barrier for the O─O bonding step resulting in sluggish process. Herein, lattice oxygen activation strategy is proposed by the electrochemical de-lithiation of LiNiO2 to catalyze the EBOR through direct O─O bonding to significantly enhance the EBOR performance. The electrochemical de-lithiation make the charge redistributed in Ni-O portion, leading to the lattice oxygen in LiNiO2 activated, thereby reducing the energy barrier of the O─O coupling step by following lattice oxygen mechanism (LOM). The constructed de-LiNiO2 exhibits excellent EBOR catalytic activity featuring current densities of 100 and 400mAcm-2 at only 1.397 and 1.431V, respectively, outperforming the currently reported analogous electrocatalysts. The formation of high-valence Ni4+ after de-lithiation leads to direct O-O coupling between lattice oxygen in de-LiNiO2 and oxygen-containing intermediates in EBOR, favoring an energetically favorable LOM pathway, thereby enhancing the EBOR performance. This work provides a new strategy to enhance the electrocatalytic activity by changing the reaction mechanism rather than focusing on catalyst design, opening up a new path for the development of advanced biomass oxidation electrocatalysts.

Construction of bifunctional MOF-based composite electrocatalysts promoting oxygen evolution reaction and glucose oxidation reaction and its kinetic deciphering

The climate crisis and the need for green and sustainable energy drive the rapid development of hydrogen production from water electrolysis. Improvements in the kinetics of the anode reaction, which governs the efficiency of water electrolysis, are essential for efficient hydrogen production and key to effectively addressing global environmental and energy challenges. Hence, we focus on improving the kinetics of the anode oxidation reaction. The multi-walled carbon nanotubes coupled with bimetallic organic framework (CoFe-MOF-74) composite electrocatalysts (CoFe-MOF-74@MWCNT) were fabricated for OER and the kinetically more favorable glucose oxidation reaction (GOR). Compared to commercial RuO2, CoFe-MOF-74@MWCNT showed superior OER catalytic performance, exhibiting a lower overpotential (273 mV) and a lower Tafel slope (55 mV dec−1) at a current density of 10 mA cm−2. Moreover, after adding glucose to the anode, the potential required of 10 mA cm−2 was only 1.291 V (vs. RHE), a reduction of 212 mV compared to the OER potential. This reduction in potential demonstrates the efficiency of our catalysts and signifies significant energy savings. The characterization results and theoretical calculations indicated that the superior OER/GOR performance of CoFe-MOF-74@MWCNT can be ascribed to the synergistic effect between MWCNT and the mixed metal nodes of the bimetallic organic framework. The doping of MWCNT promoted the catalyst charge transfer efficiency (Rct was only 5.56 Ω) in the OER process. The mixed metal nodes of CoFe-MOF-74@MWCNT provided more active sites for the electrocatalytic reaction, and promoted the bond-breaking of critical intermediates in the oxidation process, significantly reducing the free energy of catalytic intermediates and accelerating reaction kinetics. This work provides a strategy for designing multifunctional electrocatalysts for OER and biomass small molecule oxidation and highlights the potential for significant energy savings in practical applications.

Trimetallic FeNiCo layered double hydroxide catalysts for industrial-level electrochemical glycerol upgrading

Electrocatalytic conversion of glycerol, a byproduct of biodiesel production, into high value-added chemicals presents a transformative approach for biomass valorization. However, developing stable catalysts that consistently achieve industrial-grade current density at low potentials remains challenging. Herein, a highly efficient FeNiCo-Co(OH)2 electrocatalyst for the glycerol oxidation, by leveraging interconnected FeNiCo layered double hydroxide (LDH) nanosheets grown on a Co(OH)2 precursor is developed. This catalyst achieves an impressive current density of 1000 mA cm−2 at a low voltage of 1.38 V, exhibiting remarkable selectivity for formate and glycollate production. This superior performance stems from the optimized electronic structure and synergistic interactions within the FeNiCo LDHs, enabling the formation of high-valent species at lower potentials, efficient handling reaction intermediates, reduced charge transfer resistance, upward d band center and optimized mass transport, thereby enhancing glycerol adsorption and oxidation. Notably, the electrode exhibits stable operation at 120 mA cm−2 for 32 h and yields 227.50 and 104.17 mmol cm−2 for formate and glycollate, respectively, at industrial current densities for 8 h. This study unveils a novel transition metal-based glycerol oxidation reaction electrocatalyst and lays a foundation for its industrial application, highlighting significant advancements in biomass valorization.

A self-reactivated PdCu catalyst for aldehyde electro-oxidation with anodic hydrogen production

The low-potential aldehyde oxidation reaction can occur at low potential (~0 VRHE) and release H2 at the anode, enabling hydrogen production with less than one-tenth of the energy consumption required for water splitting. Nevertheless, the activity and stability of Cu catalysts remain inadequate due to the oxidative deactivation of Cu-based materials. Herein, we elucidate the deactivation and reactivation cycle of Cu electrocatalyst and develop a self-reactivating PdCu catalyst that exhibits significantly enhanced stability. Initially, in-situ Raman spectroscopy confirm the cycle involved in electrochemical oxidation and non-electrochemical reduction. Subsequently, in-situ Raman spectroscopy and X-ray absorption fine structure reveal that the Pd component accelerates the rate of the non-electrochemical reduction, thereby enhancing the stability of the Cu-based electrocatalyst. Finally, a bipolar hydrogen production device is assembled utilizing the PdCu electrocatalyst, which can deliver a current of 400 mA cm−2 at 0.42 V and operate continuously for 120 h. This work offers guidance to enhance the stability of the Cu-based electrocatalyst in a bipolar hydrogen production system.

Non-Noble Metal Catalysts for Electrooxidation of 5-Hydroxymethylfurfural.

2,5-Furandicarboxylic acid (FDCA) is a class of valuable biomass-based platform compounds. The creation of FDCA involves the catalytic oxidation of 5-hydroxymethylfurfural (HMF). As a novel catalytic method, electrocatalysis has been utilized in the 5-hydroxymethylfurfural oxidation reaction (HMFOR). Common noble metal catalysts show catalytic activity, which is limited by price and reaction conditions. Non-noble metal catalyst is known for its environmental friendliness, affordability and high efficiency. The development of energy efficient non-noble metal catalysts plays a crucial role in enhancing the HMFOR process. It can greatly upgrade the demand of industrial production, and has important research significance for electrocatalytic oxidation of HMF. In this paper, the reaction mechanism of HMF undergoes electrocatalytic oxidation to produce FDCA are elaborately summarized. There are two reaction pathways and two oxidation mechanisms of HMFOR discussed deeply. In addition, the speculation on the response of the electrode potential to HMFOR is presented in this paper. The main non-noble metal electrocatalysts currently used are classified and summarized by targeting metal element species. Finally, the paper focus on the mechanistic effects of non-noble metal catalysts in the reaction, and provide the present prospects and challenges in the electrocatalytic oxidation reaction of HMF.

Molybdenum-doping to enhance the deprotonation ability of nickel-based hydroxide electrocatalysts for ethanol oxidation

With technological advancements, the practical application of ethanol oxidation reaction (EOR) is becoming increasingly promising, yet the need for higher ethanol concentrations highlights the growing importance of the deprotonation ability (Ni2+ to Ni3+) of the catalyst. The deprotonation ability is the key step for nickel-based catalysts in EOR, as it is essential for Ni2+ to continuously undergo deprotonation to transform into Ni3+ in order to maintain the continuous EOR. Herein, we developed Mo-doped Ni(OH)2 nanosheets by a hydrothermal method. The Mo-doped Ni(OH)2 nanosheets show excellent EOR performance due to the high valence doping of Mo, the onset potential of the oxidation peak (Ni2+ to Ni3+) appears at a position with a small overpotential,. The in-situ Raman spectroscopy technique further characterized the increase in NiOOH in the process of EOR. The Mo-doped Ni(OH)2 nanocomposite catalyst facilitates the oxidation of Ni2+ into Ni3+. Based on the above theoretical guidance, Mo-doped Fe/Ni(OH)2 nanosheets was designed and synthesized. The outstanding EOR performance of the Mo-Fe/Ni(OH)2-3 showed a potential of 1.352 V at 10 mA cm−2. The catalyst was used to design three-electrode reversible zinc-ethanol-air battery (T-RZEAB), which effectively overcomes the opposing kinetic and thermodynamic requirements for EOR and oxygen reduction reaction (ORR) catalysts in the oxygen electrode. The charging voltage of T-RZEAB with Mo-Fe/Ni(OH)2-3 is 240 mV lower than that of a traditional zinc-air battery at 25 mA cm−2.

Bimetallic coordination polymers synthesized from pyrazine dicarboxylic acid serve as efficient electrocatalysts for enhancing the oxygen evolution reaction

The pursuit of cost-effective and efficient electrocatalysts for water oxidation is crucial for various applications for the storage and conversion of electrochemical energy. Coordination polymers (CPs) have garnered significant interest as potential electrocatalysts, as their catalytic efficiency can be precisely tuned through the design of coordination layers that boast highly accessible and highly reactive metal sites. However, CP-based catalysts face substantial challenges for their application in electrocatalytic oxidation processes because of their limited activity and poor stability. In this study, we employed a mixed-metal approach to develop CoxNi1-x-PDAs incorporating two functional sites specifically designed for facilitating the oxidation of water. The presence of both Co and Ni enhances electron transport through synergistic effects within the CoxNi1-x-PDAs structure. By adjusting the metal ratios in these coordination polymers, an optimized Co3/4Ni1/4-PDA demonstrated impressive performance in water oxidation under alkaline conditions during oxygen evolution reactions, a current density of 10 mA cm−2 was achieved with an overpotential of 322 mV, along with a Tafel slope measured at 87 mV dec−1. This approach involving mixed metals seeks to exploit the synergistic effects among various metal centers, which could result in efficient electrocatalysts for the oxidation of small molecules. Our findings present a promising avenue for utilizing CPs materials within the realm of electrocatalysis.

Rationally Designed L12-Pt2RhFe Intermetallic Catalyst with High CO-Tolerance for Alkaline Methanol Electrooxidation.

It is a grand challenge to deep understanding of and precise control over functional sites for the rational design of highly efficient catalysts for methanol electrooxidation. Here, an L12-Pt2RhFe intermetallic catalyst with integrated functional components is demonstrated, which exhibits exceptional CO tolerance. The Pt2RhFe/C achieves a superior mass activity of 6.43 A mgPt -1, which is 2.23-fold and 3.53-fold higher than those of PtRu/C and Pt/C. Impressively, the Pt2RhFe/C exhibits a significant enhancement in durability owing to its high CO-tolerance and stability. Density functional theory calculations reveal that high performance of Pt2RhFe intermetallic catalyst arises from the synergistic effect: the strong OH binding energy (OHBE) at Fe sites induce stably adsorbed OH species and thus facilitate the dehydrogenation step of methanol via rapid hydrogen transfer, while moderate OHBE at Rh sites promote the formation of the transition state (Pt-CO···OH-Rh) with a low activation barrier for CO removal. This work provides new insights into the role of OH binding strength in the removal of CO species, which is beneficial for the rational design of highly efficient catalysts.

Additive-free Electrodeposition of SnCoNi Trimetallic Catalysts for Ethanol Electrooxidation

SnCoNi catalysts were synthesized via electrodeposition, with and without citric acid, to assess their ethanol electrooxidation performance. The additive-free catalyst exhibited superior properties, including lower charge transfer resistance and a smaller Tafel slope compared to the citric acid-modified catalyst. Chronoamperometry testing further revealed better electrochemical stability for the additive-free catalyst, with less current loss over time. Cyclic voltammetry confirmed the enhanced ethanol oxidation activity with a relatively high current density. The improved performance is attributed to better mass transport, active site exposure, and the synergistic effects of Sn, Co, and Ni in the additive-free catalyst, making it more efficient for ethanol electrooxidation. These findings suggest that the additive-free catalyst exhibits more favorable properties for ethanol electrooxidation compared to its citric acid-modified counterpart.

Poly(3-thiophenemalonic acid) Modified NiFe Layered Double Hydroxide Electrocatalyst for Stable Seawater Oxidation at an Ampere-Scale Current Density

Poly(3-thiophenemalonic acid) Modified NiFe Layered Double Hydroxide Electrocatalyst for Stable Seawater Oxidation at an Ampere-Scale Current Density

One-Pot Fast Electrochemical Synthesis of Ternary Ni-Cu-Fe Particles for Improved Urea Oxidation

The climate crisis has become the most serious concern of human beings and environments worldwide in the 21st century. Global concerns about cancer epidemiology mainly originate from anthropogenic activities, particularly fossil-based operations. A key solution to this problem is the use of fuel cells—devices—capable of the direct conversion of fuel chemical energies like urea into electricity. To make their commercialization reasonable, one of the problems that needs to be solved is the development of anodic materials. The majority of investigations on urea oxidation are based on nickel, but its inadequate activity limits the efficiency of these devices. In this work, we propose and synthesize a Ni-Cu-Fe ternary electrocatalyst for urea oxidation through a fast and facile electrodeposition method. The properties of the synthesized material are examined by Scanning Electron Microscopy (SEM) conjugated with Energy Dispersive X-ray Spectroscopy (EDS), Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD). Its electrochemical properties were also examined in a 1 M KOH solution with and without 0.15 M urea. We found that the prepared powder is active in the electro-oxidation of urea, with 1.65 Vvs RHE required for a current density of 10 mA cm−2 and a stable potential of 2.38 Vvs RHE required for 3 h of polarization at 10 mA cm−2.

Homojunction-Incorporated Oxygen Vacancy Functionalized Spherical TiO2 Nanocrystals for the Electrochemical Detection of Chemical Oxygen Demand.

Chemical oxygen demand (COD) is a critical criterion for the analytical assessment of the degree of organic contaminants in an aqueous system. Typically, toxic and expensive reagents are employed in standardized COD analysis methods, leading to secondary pollution. In this work, we developed a rapid electrochemical method for COD detection based on the oxidation of hydroxyl radicals for organics in water by using oxygen vacancy doped anatase/rutile-TiO2 nanoparticles as electrooxidation catalysts. Homojunction interface generated increasing oxygen vacancies for enhancing electron-transfer rate and accelerating H2O oxidation to substantially improve ·OH yield. Oxygen vacancy further increased the oxygen evolution potential of the material. Initially, glucose was chosen as a standard analyte to evaluate electrochemical responses, and water from urban wastewater treatment plants was assessed as real samples subsequently. Excellent analytical characteristics were achieved with the A/R-TiO2 sensor under the optimal conditions, exhibiting a linear range from 1 to 300 mg L-1 and detection limit of 0.1 mg L-1 COD. The estimated COD values obtained from the samples were highly consistent with those determined using the conventional standard dichromate method. We have presented a fast, cost-effective, and ecologically sustainable method that outperforms the standard COD analysis method and holds great potential for the accurate determination of COD and boasts high detection sensitivity and a broad linear range.