Accelerate Electron Transfer Research Articles

Molecular Strain Accelerates Electron Transfer for Enhanced Oxygen Reduction.

Fe-N-C materials are emerging catalysts for replacing precious platinum in the oxygen reduction reaction (ORR) for renewable energy conversion. However, their potential is hindered by sluggish ORR kinetics, leading to a high overpotential and impeding efficient energy conversion. Using iron phthalocyanine (FePc) as a model catalyst, we elucidate how the local strain can enhance the ORR performance of Fe-N-Cs. We use density functional theory to predict the reaction mechanism for the four-electron reduction of oxygen to water. Several key differences between the reaction mechanisms for curved and flat FePc suggest that molecular strain accelerates the reductive desorption of *OH by decreasing the energy barrier by ∼60 meV. Our theoretical predictions are substantiated by experimental validation; we find that strained FePc on single-walled carbon nanotubes attains a half-wave potential (E1/2) of 0.952 V versus the reversible hydrogen electrode and a Tafel slope of 35.7 mV dec-1, which is competitive with the best-reported Fe-N-C values. We also observe a 70 mV change in E1/2 and dramatically different Tafel slopes for the flat and curved configurations, which agree well with the calculated energies. When integrated into a zinc-air battery, our device affords a maximum power density of 350.6 mW cm-2 and a mass activity of 810 mAh gZn-1 at 10 mA cm-2. Our results indicate that molecular strain provides a compelling tool for modulating the ORR activities of Fe-N-C materials.

Constructing a Polyoxometalate-Based Metal-Organic Framework for Photocatalytic Oxidation of Thioethers to Sulfoxides Utilizing In Situ-Generated Superoxide Radicals.

Developing new photocatalysts for the selective oxidation of thioethers to high-value-added sulfoxides under low-oxygen mild conditions is a promising but challenging strategy. Here, a new polyoxometalate-based metal-organic framework (POMOF), CoBW12-TPT, was successfully synthesized, wherein continuous π···π stacking interactions and direct coordination bonds not only strengthen the framework's stability but also accelerate electron transfer. A series of experiments and theoretical studies, including control experiments, kinetic studies, electrochemical spectroscopic analyses, and electron paramagnetic resonance, revealed the synergistic catalytic effect among Co(II) metal centers, BW12O405-, and the photosensitizer TPT. CoBW12-TPT was applied in the photocatalytic oxidation of thioethers to sulfoxides. Under irradiation, the photoinduced electron transfer of POMOF leads to the generation of superoxide radicals from O2, which controls the selective generation of sulfoxide compounds in the photocatalytic desulfurization reaction and shows good activity. In particular, it can be applied to the construction of some drug molecules such as Modafinil and Albendazole Oxide.

Accelerating electron transfer reduces CH4 and CO2 emissions in paddy soil.

As an accelerated electron transfer device, the influence of microbial electrochemical snorkel (MES) on soil greenhouse gas production remains unclear. Electron transport is the key to methane production and denitrification. We found that the N2O amount of the MES treatment was comparable to the control however the cumulative CO2 and CH4 emissions were reduced by 50% and 41%, respectively. The content of Fe2+ in MES treatment increased by 31%, which promoted the electron competition of iron reduction to methanogenesis. Furthermore, the competition among iron-reducing, nitrifying and denitrifying bacteria reduced the abundance of methanogens by 19-20%. Additionally, the MES treatment decreased the abundance of genes associated with hydrogen methanogenesis pathway by 6-19%, and inhibited the further conversion of acetyl-CoA into CH4 for acetoclastic methanogenesis. This study reveals effects of accelerating electron transfer on greenhouse gas emission, and provides a novel strategy for reducing greenhouse gas emissions in paddy soil.

Anchoring Ru-Ru2P heterojunction on P-doped graphene for enhanced HER performances of water electrolysis

Highly active and stable electrocatalysts are highly desired for the hydrogen evolution reaction (HER) in water electrolysis. In this study, a ruthenium-ruthenium phosphide heterojunction (Ru-Ru2P) anchored on phosphorus-doped graphene (PCSG) was fabricated via a mild molten salt template method. The graphene was synthesized from discarded coconut shells sourced from Hainan. We found that the heterojunction structure could accelerate electron transfer, while the graphene provided more exposed active sites, significantly enhancing the HER activity of the catalyst. The catalyst prepared at 800 °C with 30mg of RuCl3 (Ru-Ru2P/2D-PCSG-800) exhibited low HER overpotentials of 31mV in alkaline and 57mV in acidic electrolytes at a current density of 10mAcm-2, respectively, which were comparable to those of commercial 20% Pt/C catalyst (36mV in alkaline and 40mV in acidic electrolytes). Moreover, the catalyst demonstrated high stability with no significant change in current density after 125hours of operation. Density functional theory calculations revealed that the Ru-Ru2P heterojunction could rearrange charge and modify the Ru d-band center, optimizing the adsorption energy of active ⁎H (|ΔG⁎H|) and breakage energy of ⁎H-OH bond (ΔGH2O).

Study on the mechanism of regulating micromolar Fe utilization and promoting denitrification by guanosine monophosphate (GMP) based multi-signal functional material Hematin@Fe/GMP

A novel multi-signal functional material consisting of Hematin, Fe, and guanosine monophosphate (GMP) was successfully constructed (Hematin@Fe/GMP) to enhance denitrification efficiency based on the signal network regulation of electron transfer, micromolar Fe utilization, and microbial community. Hematin@Fe/GMP enhanced nitrate reduction rate by 2.33-fold with a 9.9 mg L-1 h-1 reduction rate. The mechanisms of accelerated denitrification were elaborated deeply from the electrochemical experiments, microbial metabolism activity, key enzyme activity, gene expression, and microbial community. Specifically, electrochemical experiments and X-ray photoelectron spectroscopy demonstrated that the released redox signal (Fe2+/Fe3+) promoted the increased redox substances (extracellular polymeric substances, cytochrome c, and riboflavin) to accelerate electron transfer efficiency. Metagenomic analysis suggested the released Fe utilization signal modulated siderophores genes (fhuB, fhuC, and fhuD) to promote the uptake and utilization of micromolar Fe, which was more conducive to synthesizing cytochrome c. Moreover, extracellular polymeric substances (EPS) stripping experiments demonstrated that the membrane-anchored cyt-c could shuttle in EPS and bind with Hematin@Fe/GMP to form an electrical conduit for accelerating denitrification efficiency. In inhibition experiments, Hematin@Fe/GMP could break down electron transfer barriers and restore/compensate for the electron transfer chain. Meanwhile, Hematin@Fe/GMP could restore the electrical signal disruption and synergize with the enriched signaling-capable microorganisms (Stutzerimonas and Thauera) to regulate quorum sensing. This research introduced multi-signal modulation of Hematin@Fe/GMP on denitrification and provided strategies for accelerating the biological transformation process and effectively utilizing micromolar Fe in practical applications.

Rapid Hydrolysis of Submicron Magnesium Catalyzed by In Situ-Generated Multi-Nickel Alloys.

The hydrolysis of lightweight metal-based materials is a promising technology for supplying hydrogen to portable fuel cells. Various additives for the catalytic modification of Mg hydrolysis have been investigated. Efficient catalysts and small magnesium particle sizes are key to enhancing the rate of hydrogen production. In this study, submicron Mg and in situ-generated multi-Ni alloy catalysts (NiM@Gn) are prepared and composited for the first time. Among the composites prepared, Mg-5wt.%NiM@Gn exhibits the best hydrolysis performance. This composite can release 804.4mL g-1 hydrogen within 30 s (98.32% of the total yield), and its initial hydrogen release rate is as high as 5480mL g-1 min-1, with a low apparent activation energy of hydrolysis of 10.85kJ mol-1. Submicron Mg greatly improves the rate of the hydrolysis reaction, and graphene facilitates the exfoliation of agglomerated Mg particles in water. Mg2Ni and (Fe, Ni) alloys generate microgalvanic cells with Mg in situ, significantly enhancing the electrochemical corrosion efficiency of Mg. Theoretical calculations show that these alloys accelerate electron transfer and coupling on the Mg surface. This study guides for the design and preparation of multi-catalysts and establishes the feasibility of submicron Mg for hydrogen generation through hydrolysis.

Construction of Heterostructured Ni3S2@V-NiFe(III) LDH for Enhanced OER Performance.

The oxygen evolution reaction (OER), which involves a four-electron transfer and slow kinetics, requires an efficient catalyst to overcome the high energy barrier for high-performance water electrolysis. In this paper, a novel Ni3S2@V-NiFe(III) LDH/NF catalyst was prepared via a facile two-step hydrothermal method. The constructed heterostructure of Ni3S2@V-NiFe(III) LDH increases the specific surface area and regulates the electronic structure. Furthermore, the introduction of the V element forms an electron transport chain of Ni-O-Fe-O-V-O-Ni, which optimizes the binding energy between metal active sites and oxygen evolution reaction intermediates, accelerates electron transfer, and improves self-reconstruction. With this dual regulation strategy, Ni3S2@V-NiFe(III) LDH/NF exhibits exceptional OER performance with an overpotential of 280 mV at 100 mA/cm2 and a Tafel slope of 45.4 mV/dec. This work develops a dual regulation strategy combining heterostructure formation and the doping effect, which are beneficial in the design of efficient OER catalysts.

Structural Modulation of Nanographenes Enabled by Defects, Size and Doping for Oxygen Reduction Reaction

AbstractNanographenes are among the fastest‐growing materials used for the oxygen reduction reaction (ORR) thanks to their low cost, environmental friendliness, excellent electrical conductivity, and scalable synthesis. The perspective of replacing precious metal‐based electrocatalysts with functionalized graphene is highly desirable for reducing costs in energy conversion and storage systems. Generally, the enhanced ORR activity of the nanographenes is typically deemed to originate from the heteroatom doping effect, size effect, defects effect, and/or their synergistic effect. All these factors can efficiently modify the charge distribution on the sp2‐conjugated carbon framework, bringing about optimized intermediate adsorption and accelerated electron transfer steps during ORR. In this review, the fundamental chemical and physical properties of nanographenes are first discussed about ORR applications. Afterward, the role of doping, size, defects, and their combined influence in boosting nanographenes’ ORR performance is introduced. Finally, significant challenges and essential perspectives of nanographenes as advanced ORR electrocatalysts are highlighted.

Structural Modulation of Nanographenes Enabled by Defects, Size and Doping for Oxygen Reduction Reaction.

Nanographenes are among the fastest-growing materials used for the oxygen reduction reaction (ORR) thanks to their low cost, environmental friendliness, excellent electrical conductivity, and scalable synthesis. The perspective of replacing precious metal-based electrocatalysts with functionalized graphene is highly desirable for reducing costs in energy conversion and storage systems. Generally, the enhanced ORR activity of the nanographenes is typically deemed to originate from the heteroatom doping effect, size effect, defects effect, and/or their synergistic effect. All these factors can efficiently modify the charge distribution on the sp2-conjugated carbon framework, bringing about optimized intermediate adsorption and accelerated electron transfer steps during ORR. In this review, the fundamental chemical and physical properties of nanographenes are first discussed about ORR applications. Afterward, the role of doping, size, defects, and their combined influence in boosting nanographenes' ORR performance is introduced. Finally, significant challenges and essential perspectives of nanographenes as advanced ORR electrocatalysts are highlighted.

Interfacial synergy in twinborn CoS2/CoS1.097 heterojunction to promote sulfur conversion kinetics in lithium-sulfur batteries

The rational design of sulfur hosts is essential for mitigating the shuttle effect of lithium polysulfides (LiPSs) and improving the sluggish conversion kinetics of sulfur during multi-step phase transition. Herein, a twinborn CoS2/CoS1.097 heterojunction encapsulated in N-doped hollow carbon polyhedrons and in-situ generated CNTs (CoS2/CoS1.097@NC/CNT) was elaborately synthesized and utilized as the electrocatalyst in sulfur cathodes. The CoS2/CoS1.097 heterojunction provides abundant chemisorption sites that facilitate the formation of chemical bonds with polysulfides, thereby effectively adsorbing LiPSs. More importantly, the spontaneously generated internal electric field at the CoS2/CoS1.097 interface accelerates electron transfer, which promotes the reversible transformation between LiPSs and Li2S. Additionally, the hollow carbon polyhedrons and grafted CNTs not only effectively confine sulfur, but also provide extra buffer space for the sulfur evolution reaction. Benefiting from these characteristics, the battery assembled with CoS2/CoS1.097@NC/CNT/S cathode exhibits a remarkable initial capacity of 1454.4mAh/g at 0.1C), excellent rate capability of 674.7mAh/g at 4C, and outstanding capacity retention of 604.7mAh/g over 500 cycles at 2C (∼73.1 % of initial capacity).

N, P co-doped graphite felt cathode for efficient removal of ciprofloxacin in an ascorbic acid-coupled electro-Fenton process: Simultaneously enhancing H2O2 generation and Fe3+/Fe2+ cycling.

To enhance the contaminant removal efficiency of the electro-Fenton (E-Fenton) process, a nitrogen and phosphorus co-doped graphite felt (NPGF) cathode was synthesized using an anodic oxidation technique. An ascorbic acid-coupled NPGF E-Fenton system was then established for the degradation of ciprofloxacin (CIP). The NPGF cathode featured abundant oxygen-containing functional groups (such as -COOH and -OH), which enhanced the selectivity of oxygen reduction and facilitated the formation of H2O2. The introduction of N and P doping disrupted the charge balance within the carbon framework, accelerating electron transfer. Together, the NPGF electrode and ascorbic acid enhanced the cycling of Fe3+/Fe2+ while preventing the formation of iron sludge. Under optimal conditions (ascorbic acid concentration of 0.3mM, current density of 2.0mAcm-2, pH of 3.0, aeration rate of 0.6Lmin-1, and Fe2+ concentration of 0.2mM), CIP was completely removed within 20min. The NPGF electrode exhibited excellent stability, maintaining 95.35% CIP removal even after 8 cycles. Analysis revealed that singlet oxygen primarily mediated the degradation of CIP, with its concentration measured at 1.23×10-7M. Density functional theory was used to analyze the characteristics and potential attack sites of CIP, enabling the proposal of plausible degradation pathways. Toxicity simulations and Escherichia coli growth inhibition experiments demonstrated a reduction in the toxicity of CIP and its intermediate products. This study offers a valuable reference for improving the efficiency of E-Fenton technology in antibiotic wastewater treatment.

Construction of hollow core-shell ZnO@Co3O4 p-n heterojunction for CO2 cycloaddition under visible light irradiation

In comparison to a single semiconductor, constructing p-n heterojunctions represents an efficient strategy for enhancing photocatalytic activity because of their advantages in accelerating charge separation and promoting photoabsorption. Herein, we propose a novel metal–organic framework (MOF)-assisted and controlled pyrolysis strategy for constructing a hollow core-shell p-n heterojunction photocatalyst ZnO@Co3O4. It is worth noting that the hollow core-shell heterojunction not only provides abundant active sites but also significantly facilitates the separation of photogenerated charge carriers and accelerates electron transfer. Benefiting from the above advantages, the optimized ZnO@Co3O4(400,2), obtained by pyrolysis at 400 ℃ for 2h using Zn-MOF@Co-MOF as a precursor, exhibits high activity for the cycloaddition of CO2 and epichlorohydrin, resulting in a 94% yield of 4-(chloromethyl)-1, 3-dioxolan-2-one under 1bar CO2 pressure and visible light irradiation for 2h, which is significantly superior to those of ZnO(400,2) (5%), Co3O4(400,2) (38%), and the physically mixed counterparts (55%). This work provides insightful guidance for designing efficient photocatalysts aimed at CO2 cycloaddition, thereby achieving solar to high-value-added chemical conversion efficiencies.

Highly efficient catalytic ozonation in microbubbles solubilization mode to eliminate gas odor: Accelerated electron transfer and cycling at interfacial Ag O Mn bridge

Highly efficient catalytic ozonation in microbubbles solubilization mode to eliminate gas odor: Accelerated electron transfer and cycling at interfacial Ag O Mn bridge

Crystalline-amorphous hybrid CoNi layered double hydroxides for high areal energy density supercapacitor.

Crystalline-amorphous hybrid materials have garnered significant attention in the realm of energy storage, yet simultaneously regulating the morphological and electronic structure of crystalline-amorphous hybrid remains a challenge. Herein, crystalline-amorphous hybrid CoNi-layered double hydroxides (CA-CoNi-LDHs) were constructed by a facile chronoamperometry (i-t) electrochemical activation strategy, which allows for dual modulation of both structural transformations and electronic structure of CoNi-layered double hydroxides (CoNi-LDHs). Experimental results demonstrate that the construction of a crystalline-amorphous hybrid can effectively optimize both the morphological and electronic structure of CoNi-LDHs, expose abundant defects, and raise the concentration of active Ni2+ and Co3+ species, which are conducive to increasing the active sites for energy storage. The reduced adsorption energy for OH-, the increased electron density near the Fermi energy level, coupled with the narrowed bandgap energy of CA-CoNi-LDHs are favorable for accelerating electron transfer and enhancing reaction kinetic. Consequently, the CA-CoNi-LDHs@CC electrode with high mass loading (18.8mgcm-2) delivers an impressive areal capacitance of 13,070mFcm-2 at 5mAcm-2, along with exceptional cycling stability. Moreover, the assembled asymmetric supercapacitor based on CA-CoNi-LDHs@CC possesses a high areal energy density of 0.71mWhcm-2 at a power density of 3.95mWcm-2. This work proves that construction of crystalline-amorphous hybrid materials is a viable strategy for achieving high energy density storage.

Perovskiet-like BaZrO3 nanocatalyst with rich oxygen vacancies on boosting hydrogen storage property of MgH2

Magnesium hydride (MgH2) as a promising solid hydrogen syorage material has been extensively researched. but the higher separating temperature and sluggish kinetics hinder its large-scale practical application. To solve this problem, a BaZrO3 nanocatalyst with abundant oxygen vancies is manuscripted, exerts significant improvement to the hydrogen storage performance of MgH2. Impressively, the onset dehydrogenation temperature of MgH2-10 wt% BaZrO3-Ov composite is reduced markedly from 390 °C(for pure MgH2) to 260 °C. Additionally, the composite can discharge 4.22 wt% H2 with 10 min at 275 °C and a total dehydrogenation amouut of 5.88 wt% is achieved at 300 °C. For hydrogen absorption, the composite can rapidly recharge hydrogen at a low temperature of 150 °C and approximately 5.08 wt% H2 can be absorbed at 275 °C within 10 min. The dehydrogenation activation energy of BaZrO3-Ov-added MgH2 is as low as 92.61 kJ mol−1 compared to pure MgH2 (164.78 kJ mol−1). Meantime, the composite presents unexceptionable reversible kinetic performance with a retention rate of 97.35 % after 10 cycles. The excellent catalytic effects can be attributed to the in-situ generation of ZrO2-Ov, BaO-Ov and ZrH2 from BaZrO3-Ov during the first de-/rehydrogenation cycle, which function as nanosized active sites on MgH2 matrix to accelerate electron transfer and provide abundant hydrogen diffusion channels. Density functional theory calculations results verify that the Mg–H length and dehydrogenation energy barrier are ameliorated through BaZrO3-Ov. This work provides a unique perspective on modification MgH2 by perovskiet-like BaZrO3-Ov nanocatalyst.

Synthesis of hollow corn-like P-doped bimetallic FeNi-MIL-88 nanorods using a self-template strategy for nitrobenzene monitoring

This study developed a hollow, corn-like P-doped bimetallic FeNi-MIL-88 nanosphere composite, referred to as P-FeNi-MIL-88@C, using a simple self-template strategy. The synthesis began with the hydrothermal formation of a stable bipyramidal FeNi-MIL-88 precursor, where Ni was incorporated into Fe-MIL-88 nanorods. Subsequently, phosphorus was introduced through a one-step phosphidation process. The inclusion of Ni enhanced surface atom mobility and rearrangement, yielding a denser and more uniform particle distribution, which improved electron transfer efficiency. The hollow structure of the P-doped corn-like P-FeNi-MIL-88@C reduced reaction resistance and accelerated electron transfer, leading to exceptional electrocatalytic performance for nitrobenzene (NB) detection. The sensor demonstrated high sensitivity, a broad linear range (0.37–1106.67 μM), and a low detection limit (0.17 μM, S/N = 3). When tested with real water samples, it achieved a recovery rate of 98.7–102.1 %, underscoring its applicability for practical environmental monitoring.

Deciphering the role of biochar pseudocapacitance strengthening in promoting syntrophic methanogenesis: Microbial capacitance-tropism in propionate metabolism

The redox functional groups of biochar can act as pseudocapacitance, alleviating acid accumulation and facilitating electron transfer in anaerobic digestion. Fe modification further enhances its pseudocapacitance properties. However, the specific role of pseudocapacitance strengthening in the electron transfer of volatile fatty acid syntrophic methanogenesis, as well as the factors inducing the enrichment behavior and metabolic mechanisms of microbes on its surface, remain unclear. In this study, experiments using acetate and propionate as substrates were conducted with the addition of biochar and electro-enhanced biochar, while 16S rRNA gene amplicon sequencing and metagenomic analysis were employed to investigate the underlying mechanisms. The results demonstrate that strengthening biochar’s pseudocapacitance significantly facilitates the electron shunt by accepting electrons, accelerating NADH/NAD+ conversion and ATP synthesis. This further promotes the oxidative degradation of propionate and acetate through the methylmalonyl-CoA (MMC) and syntrophic acetate oxidation (SAO) pathways. During methanogenesis, biochar directly transfers electrons to methanogens, with the strengthened pseudocapacitance further accelerating electron transfer through the CO2 reduction pathway and specifically promoting the methanation of propionate rather than acetate. Moreover, during propionate metabolism, Coprothermobacter and Methanosarcina exhibit capacitance-tropism in their enrichment on biochar, serving as key functional contributors to the biochar-microbial aggregates. These findings provide valuable insights for selecting exogenous materials in engineering applications to alleviate acid accumulation in anaerobic digestion systems.

MIL-88-derived porous carbon rod-supported FePS3 nanosheet arrays for robust sodium storage

Ternary metal phosphorus trisulfide (MPS3) has emerged as an excellent candidate for use as an anode in sodium-ion batteries, characterized by its unique layered structure, easily tunable physicochemical properties, and high theoretical capacity. However, its intrinsic challenges such as low electrical conductivity and susceptibility to fragmentation have led to unsatisfactory rate and cyclic capability. Herein, the intriguing microcomposite structure of porous carbon rod-supported FePS3 nanosheet arrays (FePS3@CR) is ingeniously constructed in situ via the phospho‑sulfurization of MIL-88. FePS3@CR showcases multiple structural advantages, including enhanced electrical conductivity, increased surface area, accelerated electron transfer rate, and mitigated structural stress. These combined benefits endow FePS3@CR with improved rate capability (808.0 and 474.3 mAh g−1 at 0.1 and 10 A g−1, respectively) and cyclic life (94.5 % retention after 1500 loops at 2 A g−1). The assembled full battery also demonstrates robust cycling stability, retaining 94.2 % of its capacity after 1100 loops at 0.5 A g−1. The specific sodium storage process of the FePS3 electrode is investigated through ex-situ structure analysis. This work presents innovative structural designs potentially improving the energy storage performance of MPS3 material system.

Cation‐Vacancy Engineering Modulated Perovskite Oxide for Boosting Electrocatalytic Conversion of Polysulfides

AbstractLithium‐sulfur batteries face challenges like polysulfide shuttle and slow conversion kinetics, hindering their practical applications in renewable energy storage and electric vehicles. Herein, a solution to solve this issue is reported by using a cation vacancy engineering strategy with rational synthesis of La‐deficient LaCoO3 (LCO‐VLa). The introduction of cation vacancies in LCO‐VLa modifies the geometric structure of coordinating atoms, exposing Co‐rich surface with more catalytically active surfaces. Meanwhile, the d‐band center of LCO‐VLa shifts toward the Fermi level, enhancing polysulfide adsorption. Furthermore, multivalent cobalt ions (Co3+/Co4+) induced by charge compensation enhance the electrical conductivity of LCO‐VLa, accelerating electron transfer processes and improving catalytic performance. Theoretical calculations and experimental characterizations demonstrate that La‐deficient LCO‐VLa effectively suppresses the polysulfide shuttle, reduces the energy barrier for polysulfide conversion, and accelerates redox reaction kinetics. LCO‐VLa‐based batteries demonstrate exceptional rate performance and cycling stability, retaining 70% capacity after nearly 500 cycles at 1.0 C, with a minimal decay rate of 0.055% per cycle. These findings highlight the significance of cation vacancy engineering for exploring precise structure‐activity relationships during polysulfides conversion, facilitating the rational design of catalysts at the atomic level for lithium‐sulfur batteries.

Surface and morphology modulated adsorption-activation of trace concentration hydrogen peroxide with multiple electron transfer pathways and sustained Fenton reactions

To promote mass transfer and activation of hydrogen peroxide (H2O2) in Fenton-like reactions, a novel MOFs-derived Fe2O3 was tailor-designed through surface sulfur modification and morphology tuning for degrading a group of persistent micropollutants, i.e., sulfamethoxazole, enrofloxacin, and ofloxacin. The introduction of Ca2+ and Mg2+ modulated the growth of crystal clusters to prevent aggregation of Fe2O3 nanoparticles and provide more reaction sites. Likewise, the abundant acid sites (–SO3H) promote the chemisorption of even trace-concentration H2O2 (S–O bonding), whereas the S–Fe bonding accelerates electron transfer to promote the Fe3+/Fe2+ cycle and thus the H2O2 utilization. More interestingly, surface-adsorbed H2O is found to be activated to form •OH, due to electron-poor Fe sites formed after detachment of –SO3H, demonstrating a sustained radical yield for the micropollutant degradation. This study opens new perspectives in catalyst design to ultimately realize the utilization of trace-concentration H2O2 and even H2O in Fenton-like systems.