Co3 O4 Research Articles

Highly Efficient and Selective Visible-Light Driven Photoreduction of CO2 to CO by Metal-Organic Frameworks-Derived NiCoO Porous Microrods.

Photocatalytic CO2 reduction by solar energy into carbonaceous feedstock chemicals is recognized as one of the effective ways to mitigate both the energy crisis and greenhouse effect, which fundamentally relies on the development of advanced photocatalysts. Here, the exploration of porous microrod photocatalysts based on novel NiCoO solid solutions derived from bimetallic metal-organic frameworks (MOFs) is reported. They exhibit overall enhanced photocatalytic performance with both high activity and remarkable selectivity for reducing CO2 into CO under visible-light irradiation, which are superior to most related photocatalysts reported. Accordingly, the Ni0.2 -Co0.8 -O microrod(MR-N0.2 C0.8 O) photocatalyst delivers high efficiency for photocatalytic CO2 reduction into CO at a rate up to ≈277 µmol g-1 h-1 , which is ≈35 times to that of its NiO counterpart. Furthermore, they display a high selectivity of ≈85.12%, which is not only better than that of synthesized Co3 O4 (61.25%) but also superior to that of reported Co3 O4 -based photocatalysts. It is confirmed that the Co and Ni species are responsible for CO2 CO conversion activity and selectivity, respectively. In addition, it is verified, by adjusting the Ni contents, that the band structure of NiCoO microrods can be tailored with favorable reduction band potentials, which thus enhance the selectivity toward CO2 photoreduction.

Balancing Electrolyte Donicity and Cathode Adsorption Capacity for High-Performance LiS Batteries.

LiS batteries with high theoretical capacity are attracting attention as next-generation energy storage systems. Much effort has been devoted to the introduction of cathode materials with strong adsorption to sulfide species, but it is presented that this selection should be refined in the application of high donicity electrolytes. The oxides with different adsorption capacities are explored while controlling the electrolyte donicity, confirming the trade-off effect between the donicity and the adsorption capacity for sulfur conversion. Specifically, a cathode substrate containing oxide nanoparticles of MgO, NiO, Fe2 O3 , Co3 O4 , and V2 O5 is prepared with spectra in adsorption capacity as well as low and high donicity electrolytes by controlling the concentration of LiNO3 salt. Strong adsorbent oxides such as Co3 O4 and V2 O5 cause competitive adsorption of electrolyte salts in high donicity electrolytes, resulting in poor cell performance. High cell performance is achieved on weakly adsorbing oxides of MgO or NiO with high donicity electrolytes; the MgO-containing cathode cell delivers a high discharge capacity of 1394 mAh g-1 at 0.2 C. It is believed that understanding the interactions between electrolytes and adsorbent substrates will be the cornerstone of high-performance LiS batteries.

Magnetic Field Enhanced Electrocatalytic Oxygen Evolution of NiFe-LDH/Co3 O4 p-n Heterojunction Supported on Nickel Foam.

Here, a strategy to regulate the electron density distribution by integrating NiFe layered double hydroxides (NiFe-LDH) nanosheets with Co3 O4 nanowires to construct the NiFe-LDH/Co3 O4 p-n heterojunction supported on nickel foam (NiFe-LDH/Co3 O4 /NF) for electrocatalytic oxygen evolution reaction (OER) is proposed. The p-n heterojunction can induce the charge redistribution in the heterogeneous interface to reach Fermi level alignment, thus modifying the adsorption free energy of *OOH and improving the intrinsic activity of the catalyst. As a result, NiFe-LDH/Co3 O4 /NF exhibits outstanding OER performance with a low overpotential of 274mV at a current density of 50mAcm-2 and long-time stability over 90h. Moreover, NF can serve as a magnetic core that induces the exchange bias effect between the magnetic substrate and the active species under the action of the magnetic field, resulting in decreased magnetoresistance and weakened scattering of spin electrons, which further lowers the OER overpotential by 25mV @ 50mAcm-2 under a 10000G magnetic field. This work provides a new perspective on the design of p-n heterojunction catalysts and a deeper understanding of the magnetic field-enhanced electrocatalytic reactions.

Hydrophobization Engineering of the Air-Cathode Catalyst for Improved Oxygen Diffusion towards Efficient Zinc-Air Batteries.

Poor oxygen diffusion at multiphase interfaces in an air cathode suppresses the energy densities of zinc-air batteries (ZABs). Developing effective strategies to tackle the issue is of great significance for overcoming the performance bottleneck. Herein, inspired by the bionics of diving flies, a polytetrafluoroethylene layer was coated on the surfaces of Co3 O4 nanosheets (NSs) grown on carbon cloth (CC) to create a hydrophobic surface to enable the formation of more three-phase reaction interfaces and promoted oxygen diffusion, rendering the hydrophobic-Co3 O4 NSs/CC electrode a higher limiting current density (214 mA cm-2 at 0.3 V) than that (10 mA cm-2 ) of untreated-Co3 O4 NSs/CC electrode. Consequently, the assembled ZAB employing hydrophobic-Co3 O4 NSs/CC cathode acquired a higher power density (171 mW cm-2 ) than that (102 mW cm-2 ) utilizing untreated-Co3 O4 NSs/CC cathode, proving the enhanced interfacial reaction kinetics on air cathode benefiting from the hydrophobization engineering.

Overdoping Strategy for Preparing a Two-Phase Oxide Electrocatalyst to Boost Oxygen Evolution Reaction.

The oxygen evolution reaction is of great significance to the production of hydrogen from high efficiency electrolytic water, hydrogen oxygen fuel cell and other energy conversion devices, but there are many challenges such as high cost, low efficiency and poor stability of catalysts. Among non-precious metal catalysts, oxide has its unique advantages. We used overdoping strategy to prepare two-phase oxide electrocatalyst SrCo0.9 Fe0.05 Mo0.35 Ox (SCFM0.35 ) containing double perovskite and Co3 O4 with excellent OER electrocatalytic activity and stability in alkaline solution. It required an overpotential of 361.7 mV to reach a 10 mA cm-2 current density and its performance only degrades by 3.48% after 1000 CV cycles accelerated stability tests, whose electrochemical performance is superior to that of single-phase double perovskites and undoped perovskites. SrCo0.9 Fe0.1 O3 (SCF) ordinary perovskite is doped with slightly molybdenum (Mo), and then the ordinary perovskite turns into double perovskite because of the polyvalence characteristics of Mo. When Mo is overdoped, Co3 O4 phase was precipitated while Mo entered perovskite phase. This process causes lattice distortion and makes the surface electronic structure benign changes. Furthermore, the microscopic morphology of the material surface and the valence state of cobalt element are changed, thereby improving the microenvironment of the electrochemical process.

Selective Extraction of Transition Metals from Spent LiNix Coy Mn1-x-y O2 Cathode via Regulation of Coordination Environment.

The complexity of chemical compounds in lithium-ion batteries (LIBs) results in great difficulties in the extraction of multiple transition metals, which have similar physicochemical characteristics. Here, we propose a novel strategy for selective extraction of nickel, cobalt, and manganese from spent LiNix Coy Mn1-x-y O2 (NCM) cathode through the regulation of coordination environment. Depending on adjusting the composition of ligand in transition metal complexes, a tandem leaching and separation system is designed and finally enables nickel, cobalt, and manganese to enrich in the form of NiO, Co3 O4 , and Mn3 O4 with high recovery yields of 99.1 %, 95.1 %, and 95.3 %, respectively. We further confirm that the combination of different transition metals with well-designed ligands is the key to good selectivity. Through our work, fine-tuning the coordination environment of metal ions is proved to have great prospects in the battery recycling industry.

Single-Atom Tailored Hierarchical Transition Metal Oxide Nanocages for Efficient Lithium Storage.

Mitigating the mechanical degradation and enhancing the ionic/electronic conductivity are critical but challengeable issues toward improving electrochemical performance of conversion-type anodes in rechargeable batteries. Herein, these challenges are addressed by constructing interconnected 3D hierarchically porous structure synergistic with Nb single atom modulation within a Co3 O4 nanocage (3DH-Co3 O4 @Nb). Such a hierarchical-structure nanocage affords several fantastic merits such as rapid ion migration and enough inner space for alleviating volume variation induced by intragrain stress and optimized stability of the solid-electrolyte interface. Particularly, experimental studies in combination with theoretical analysis verify that the introduction of Nb into the Co3 O4 lattice not only improves the electron conductivity, but also accelerates the surface/near-surface reactions defined as pesudocapacitance behavior. Dynamic behavior reveals that the ensemble design shows huge potential for fast and large lithium storage. These features endow 3DH-Co3 O4 @Nb with remarkable battery performance, delivering ≈740mAhg-1 after ultra-long cycling of 1000 times under a high current density of 5Ag-1 . Importantly, the assembled 3DH-Co3 O4 @Nb//LiCoO2 pouch cell also presents a long-lived cycle performance with only ≈0.059% capacity decay per cycle, inspiring the design of electrode materials from both the nanostructure and atomic level toward practical applications.

Overturned Loading of Inert CeO2 to Active Co3 O4 for Unusually Improved Catalytic Activity in Fenton-Like Reactions.

In the past decades, numerous efforts have been devoted to improving the catalytic activity of nanocomposites by either exposing more active sites or regulating the interaction between the support and nanoparticles while keeping the structure of the active sites unchanged. Here, we report the fabrication of a Co3 O4 -CeO2 nanocomposite via overturning the loading direction, i.e., loading an inert CeO2 support onto active Co3 O4 nanoparticles. The resultant catalyst exhibits unexpectedly higher activity and stability in peroxymonosulfate-based Fenton-like reactions than its analog prepared by the traditional impregnation method. Abundant oxygen vacancies (Ov with a Co⋅⋅⋅Ov ⋅⋅⋅Ce structure instead of Co⋅⋅⋅Ov ) are generated as new active sites to facilitate the cleavage of the peroxide bond to produce SO4 .- and accelerate the rate-limiting step, i.e., the desorption of SO4 .- , affording improved activity. This strategy is a new direction for boosting the catalytic activity of nanocomposite catalysts in various scenarios, including environmental remediation and energy applications.

Facilely-prepared sulfide-doped Co3O4 nanocomposite as a boosted catalyst for activating Oxone to degrade a sunscreen agent

BackgroundAs 2-phenylbenzimidazole-5-sulfonic acid (PSA) is increasingly consumed as a sunscreen agent, release of PSA to water bodies has caused threats to aquatic ecology, such as endocrine disruption, and reproductive inhibition. While Oxone-derived sulfate radicals are useful for treating such emerging contaminants, and cobalt is the most capable metal for activating Oxone, Co3O4 (CO) nanoparticles (NPs) suffer from serious agglomeration, exhibiting low surface areas and catalytic activities even though CO NPs are commercially available. MethodsFor utilizing accessibility of commercial CO NPs and improving their catalytic activities, a facile technique is proposed here to modify CO NPs through a straightforward sulfidization process for doping CO with cobalt sulfide (CS). Significant findingsThe sulfidization process changes surficial properties of CO chemically, and transforms the morphology of CO NPs to a composite of inter-penetrated nanosheet and NP, making this CS-doped CO (CSCO) possess more superior properties of electron transfer and textural characteristics than CO. Thus, CSCO shows a higher catalytic activity for activating Oxone to degrade PSA. Ea of PSA degradation by CSCO+Oxone (i.e., 38.1 kJ/mol) is also much lower than the reported values. The activation mechanism and degradation pathway of PSA degradation by CSCO+Oxone is investigated here through theoretical calculation and experimental evidences to provide valuable insights into degradation behaviors of PSA.

3D Flower-Like Zinc Cobaltite for Electrocatalytic Reduction of Nitrate to Ammonia under Ambient Conditions.

Nitrate (NO3 - ) as a common pollutant of groundwater causes drinking water safety problems and seriously endangers people's health. Electrochemical reduction of nitrate to ammonia under ambient condition is a green and significant route to reduce the concentration of NO3 - and produce ammonia (NH3 ), known as a complement to the Haber-Bosch reaction. Currently, noble-metal electrocatalysts are often used in electrochemical reduction of NO3 - , but high cost and scarcity limited their application. Herein, three-dimensional (3D) flower-like zinc cobaltite (ZnCo2 O4 ) electrocatalyst was developed to convert nitrate into ammonia at room temperature. The NH3 yield rate could reach up to around 2100 μg mg-1 h-1 at a potential of -0.6 V vs. reversible hydrogen electrode (RHE), which was around 2.0 times higher than that of pristine Co3 O4 . In addition, the NH3 faradaic efficiency of ZnCo2 O4 electrocatalyst could reach around 95.4 % at potential of -0.4 V vs. RHE with good structural and morphological stability, which surpassed most reported non-noble metal-based electrocatalysts. Further studies concluded that the improved activity of electrocatalytic NO3 - reduction was ascribed to the existence of abundant active sites and the charge transfer from Co atoms to Zn atoms after Zn doping. Importantly, this work opens a new path for the development of Co-based materials as electrocatalysts for reducing nitrate to ammonia.

Vanadium-Incorporated CoP2 with Lattice Expansion for Highly Efficient Acidic Overall Water Splitting.

A proton exchange membrane water electrolyzer (PEMWE) in acidic medium is a hopeful scenario for hydrogen production using renewable energy, but the grand challenge lies in substituting noble-metal catalysts. Herein, a robust electrocatalyst of V-CoP2 porous nanowires arranged on a carbon cloth is successfully fabricated by incorporating vanadium into the CoP2 lattice. Structural characterizations and theoretical analysis indicate that lattice expansion of CoP2 caused by V incorporation results in the upshift of the d-band center, which is conducive to hydrogen adsorption for boosting the hydrogen evolution reaction (HER). Besides, V promotes surface reconstruction to generate a thicker Co3 O4 layer with an oxygen vacancy that enhances acid-corrosion resistance and optimizes the adsorption of water and oxygen-containing species, thus improving activity and stability toward the oxygen evolution reaction (OER). Accordingly, it presents a superior acidic overall water splitting activity (1.47 V@10 mA cm-2 ) to Pt-C/CC||RuO2 /CC (1.59 V@10 mA cm-2 ), and remarkable stability. This work proposes a new route to design efficient non-noble metal electrocatalysts for PEMWE.

Using Metal Cation to Control the Microstructure of Cobalt Oxide in Energy Conversion and Storage Applications.

Herein, a facile and efficient synthesis of microstructured Co3 O4 for both supercapacitor and water-splitting applications is reported. Metal cations (Fe3+ , Cu2+ ) serve as structure-directing agents regulating the structure of Co compounds, which are subsequently annealed to yield Co3 O4 . Detailed characterizations and density functional theory (DFT) calculations reveal that the in situ Cl-doping introduces oxygen defects and provides abundant electroactive sites, and narrows the bandgap, which enhances the electron excitation of the as-formed Co3 O4 . The as-prepared Cl-doped Co3 O4 hierarchical nanospheres (Cl-Co3 O4 -h) display a high specific capacitance of 1629 F g-1 at 1 A g-1 as an electrode for supercapacitors, with excellent rate capability and cyclability. The Cl-Co3 O4 -h//activated carbon (AC) asymmetric supercapacitor (ASC) electrode achieves a specific capacitance of 237 F g-1 at 1 A g-1 , with an energy density of 74 Wh kg-1 at a power density of 807 W kg-1 and even maintains 47 Wh kg-1 at the higher-power density of 24.2 kW kg-1 . An integrated electrolyzer for water-splitting with Cl-Co3 O4 -h as both cathode and anode can be driven by Cl-Co3 O4 -h//AC ASC. The electrolyzer provides a high current density of 35 mA cm-2 at a cell voltage of 1.6 V, with good current density retention over 50 h.

Preparation of Practical High-Performance Electrodes for Acidic and Alkaline Media Water Electrolysis.

The synthesis of electrocatalyst and the electrode preparation were merged into a one‐step process and proved to be a versatile method to synthesize metal oxide electrocatalysts on the conductive carbon paper (CP). Very simply, the metal precursor deposited on the CP was thermally treated by a torch‐gun for just 6 s, resulting in the formation of RuO2, Co3O4, and mixed oxide nanoparticles. The material could be directly used as working electrode for oxygen evolution reaction (OER). Compared with commercial and other state‐of‐the‐art electrocatalysts, the fabricated electrode showed a superior electrocatalytic activity for OER in 1 m HClO4 and 1 m KOH in terms of not only a low overpotential to reach 10 mA cm−2 but also a high current density at 1.6 VRHE with satisfying a long‐term stability. The novel strategy without requiring time‐consuming and uneconomical steps could be expanded to the preparation of various metal oxides on conductive substrates towards diverse electrocatalytic applications.

A Comparative Study of Cobalt Chalcogenides as the Electrode Materials on Lithium-Sulfur Battery Performance.

Lithium-sulfur batteries, as viable options for energy storage, have gained popularity because of their high energy density. However, the poor conductivity of sulfur and Li2 S, as well as the shuttling effect of lithium polysulfides, seriously limits their commercialization. Herein, cobalt chalcogenides (Co3 O4 , CoS, and Co3 Se4 ) supported by reduced graphene oxide are synthesized as the electrode materials, which feature high conductivity, rapid kinetic conversion, and catalytic effect. Based on complementary experimental outputs and advanced computation, it is revealed that the change in anion results in distinctive performance. Among them, the cathode material based on Co3 Se4 /reduced graphene oxide is the best. The reasons can be ascribed to the conductive and catalytic improvement. This comparative study provides guidelines in the design of lithium-sulfur batteries via the meticulous regulation of the anions.

Nickel Cobaltite Nanoplate-Based Electrochemical Sensing Platform from Printable Inks for Simultaneous Detection of Dopamine and Uric Acid.

2D metal oxide-based nanomaterials have emerged as an exciting area of research owing to their rich electrochemical properties and diverse applications, including biosensors. In this work, we have synthesized ultra-thin Co3 O4 , NiO, and NiCo2 O4 nanostructures supported on a carbon cloth and printed graphite/Kapton substrates following thermal reduction of self-assembled metal alkanethiolates. These nanostructures act as a sensing platform for simultaneous detection of dopamine (DA) and uric acid (UA), important biological molecules in physiological and pathological tests. The ultrathin 2D nanoplates of NiCo2 O4 spinel formed in this study exhibit high electrochemical activity than pristine NiO and Co3 O4 . The electrochemical characterization studies indicate that NiCo2 O4 possesses a high potential for DA and UA with a peak separation of ∼140 mV, high sensitivity, and excellent selectivity. The low-cost and disposable, single-shot probe biosensors fabricated in this work possess a wide working range of 0.001-1000 μM with detection limits of 0.33 and 0.49 nM for DA and UA, respectively, with a practically achievable limit of quantification of ∼1 nM. Multiple sensing electrodes are printed on graphite/Kapton all at once following this method with improved reproducibility for DA and UA sensing further extending the scope of work towards mass fabrication and practical usage.

Tailoring Co3d and O2p Band Centers to Inhibit Oxygen Escape for Stable 4.6 V LiCoO2 Cathodes.

High-voltage LiCoO2 delivers a high capacity but sharp fading is a critical issue, and the capacity decay mechanism is also poorly understood. Herein, we clarify that the escape of surface oxygen and Li-insulator Co3 O4 formation are the main causes for the capacity fading of 4.6 V LiCoO2 . We propose the inhibition of the oxygen escape for achieving stable 4.6 V LiCoO2 by tailoring the Co3d and O2p band center and enlarging their band gap with MgF2 doping. This enhances the ionicity of the Co-O bond and the redox activity of Co and improves cation migration reversibility. The inhibition of oxygen escape suppresses the formation of Li-insulator Co3 O4 and maintains the surface structure integrity. Mg acts as a pillar, providing a stable and enlarged channel for fast Li+ intercalation/extraction. The modulated LiCoO2 shows almost zero strain and achieves a record capacity retention at 4.6 V: 92 % after 100 cycles at 1C and 86.4 % after 1000 cycles at 5C.

Co3 O4 Nanowires Capable of Discharging Low Voltage Electricity Showing Potent Antibacterial Activity for Treatment of Bacterial Skin Infection.

Overuse of antibiotics has led to multidrug resistance in bacteria, posing a tremendous challenge to the healthcare system. There is an urgent need to explore unconventional strategies to overcome this issue. Herein, for the first time, we report a capacitive Co3 O4 nanowire (NW) electrode coated on flexible carbon cloth, which is capable of eliminating bacteria while discharging, for the treatment of skin infection. Benefiting from the unique NW-like morphology, the Co3 O4 NW electrode with increased active sites and enhanced capacitive property exhibits a prominent antibacterial effect against both Gram-positive and Gram-negative bacteria after charging at a low voltage of 2V for 30min. Furthermore, the electrode is demonstrated to be recharged for multiple antibacterial treatment cycles without significant change of antibacterial activity, allowing for practical use in a non-clinical setting. More importantly, this Co3 O4 NW electrode is capable of damaging bacterial cell membrane and inducing the accumulation of intracellular reactive oxygen species without impairing viability of skin keratinocytes. In a mouse model of bacterial skin infection, the Co3 O4 electrode shows significant therapeutic efficacy by eradicating colonized bacteria, thus accelerating the healing process of infected wounds. This nanostructured capacitive electrode provides an antibiotic-free, rechargeable, and wearable approach to treat bacterial skin infection.

Tailoring Competitive Adsorption Sites by Oxygen-Vacancy on Cobalt Oxides to Enhance the Electrooxidation of Biomass.

The electrooxidation of 5-hydroxymethylfurfural (HMF) offers a promising green route to attain high-value chemicals from biomass. The HMF electrooxidation reaction (HMFOR) is a complicated process involving the combined adsorption and coupling of organic molecules and OH- on the electrode surface. An in-depth understanding of these adsorption sites and reaction processes on electrocatalysts is fundamentally important. Herein, the adsorption behavior of HMF and OH- , and the role of oxygen vacancy on Co3 O4 are initially unraveled. Correspondingly, instead of the competitive adsorption of OH- and HMF on the metal sites, it is observed that the OH- can fill into oxygen vacancy (Vo) prior to couple with organic molecules through lattice oxygen oxidation reaction process, which could accelerate the rate-determining step of the dehydrogenation of 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) intermediates. With the modulated adsorption sites, the as-designed Vo-Co3 O4 shows excellent activity for HMFOR with the earlier potential of 90 and 120mV at 10mA cm-2 in 1 m KOH and 1 m PBS solution. This work sheds insight on the catalytic mechanism of oxygen vacancy, which benefits designing a novel electrocatalysts to modulate the multi-molecules combined adsorption behaviors.

The Roles of Composition and Mesostructure of Cobalt-Based Spinel Catalysts in Oxygen Evolution Reactions.

By using the crystalline precursor decomposition approach and direct co‐precipitation the composition and mesostructure of cobalt‐based spinels can be controlled. A systematic substitution of cobalt with redox‐active iron and redox‐inactive magnesium and aluminum in a cobalt spinel with anisotropic particle morphology with a preferred 111 surface termination is presented, resulting in a substitution series including Co3O4, MgCo2O4, Co2FeO4, Co2AlO4 and CoFe2O4. The role of redox pairs in the spinels is investigated in chemical water oxidation by using ceric ammonium nitrate (CAN test), electrochemical oxygen evolution reaction (OER) and H2O2 decomposition. Studying the effect of dominant surface termination, isotropic Co3O4 and CoFe2O4 catalysts with more or less spherical particles are compared to their anisotropic analogues. For CAN‐test and OER, Co3+ plays the major role for high activity. In H2O2 decomposition, Co2+ reveals itself to be of major importance. Redox active cations in the structure enhance the catalytic activity in all reactions. A benefit of a predominant 111 surface termination depends on the cobalt oxidation state in the as‐prepared catalysts and the investigated reaction.

Amplified Peroxidase-like Activity of Co2+ Using 8-Hydroxyquinoline and Its Application for Ultrasensitive Colorimetric Detection of Clioquinol.

8-Hydroxyquinoline (8HQ) and its derivatives display diverse bioactivities and therapeutic potentials. In this study, we unveiled that 8HQ can boost the peroxidase-like activity of Co2+ in the presence of bicarbonate (HCO3 - ) in neutral pH at room temperature. With 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonate) (ABTS) as the substrate, the formed Co2+ /8HQ/HCO3 - complex shows robust catalytic activity with the turnover number (kcat ) tens to hundreds of times higher than that of Co3 O4 and other Co2+ complexes in terms of per cobalt ion. This system was used to design colorimetric sensors for ultrasensitive detection of 8HQ-based drugs by activating the activity of Co2+ . Take detecting clioquinol as an example, a detection limit of 2.4 nM clioquinol with a linear range from 0.01 to 0.2 μM was obtained. This work not only revealed a new kind of ligand that activated the activity of Co2+ , but also provided a facile, low-cost, ultrasensitive, easy-to-use, and universal strategy for sensing various 8HQ-based drugs. Further development of this catalytic system might be beneficial to overcome drug resistance by combined medication.