Accelerate Electron Transfer Research Articles

Synergistic effect of rGO decoration on ZnFe2O4 nanorods for low concentration detection of ammonia at room temperature with high selectivity and response

This study introduces an improved sensor for detecting ammonia (NH₃) gas using Zinc Ferrite (ZF) decorated with reduced graphene oxide (rGO) films, prepared through spray pyrolysis and spin coating methods. NH₃, a major pollutant in fertilizer production, poses significant health and environmental risks even at low concentrations. Therefore, detecting NH₃ below exposure limits (25 ppm) is crucial for protecting ecosystems and human health. The prepared optimal rGO concentration and ZF (ZFG1.5) sensor exhibit excellent NH₃ response (45) towards 1 ppm, which is sevenfold better than the ZF film without rGO decoration. This enhancement is attributed to the ZF nanorods on the surface of the rGO, establishing a firm surface interaction with the ZF. This configuration accelerates electron transfer and promotes the adsorption/desorption of gas molecules, further contributing to the improved gas-solid interaction. Besides, the sensor demonstrated excellent repeatability (1.15 %), long-term stability, and high humidity tolerance (coefficient of variation 1.48 %). Additionally, the ZFG1.5 sensor showed a distinct selectivity for NH₃ in a mixed gas environment. The ZFG1.5 sensor is promising for real-time NH₃ monitoring below exposure limits, making it a valuable tool for environmental and health safety.

Oxygen vacancies-rich CoMoO4 nanosheets facilitate the electroreduction of nitrite to ammonia

Electrocatalytic reduction is a promising method to remove NO2−; not only can it deal with environmental issues, but it can also recycle NO2− to form NH3. This study involved the preparation of oxygen vacancies-rich monoclinic cobalt molybdate nanosheets on nickel foam (CoMoO4/NF) employing a hybrid approach of hydrothermal and calcination reduction techniques renders highly effective catalysts for electroreduction of nitrite (NO2−RR). The presence of oxygen vacancies increases carrier density, enhancing electrical conductivity, reducing resistance, and accelerating electron transfer. Additionally, it serves as an active site for absorbing NO2−. In an aqueous solution containing 0.5 M Na2SO4 and 0.1 M NO2−, the Faraday efficiency (FE) of CoMoO4/NF reaches an impressive 98.6 ± 0.02 % at −0.8 V vs. RHE, and NH3 yield demonstrates a commendable performance, attaining 32.72 ± 0.17 mg h−1 cm−2. Meanwhile, it exhibits robust and enduring characteristics throughout the stability tests. Employing CoMoO4/NF as the cathode, the Zn−NO2− battery demonstrates a peak power density of 5.94 mW cm−2 alongside an NH3 yield of 3.88 mg h−1 cm−2 and an FE of 91.88 %. Furthermore, density functional theory calculations uncover the significant influence of oxygen vacancies on enhancing nitrite adsorption and activation over the CoMoO4 surface and bring to light possible reaction pathways.

Pre-anoxic electro-stimulation enhanced simultaneous nitrification–denitrification in single-stage electrolysis-integrated sequencing batch biofilm reactor

Simultaneous nitrification–denitrification (SND) is a promising nitrogen removal process. However, total nitrogen (TN) removal is limited due to unsatisfactory denitrification. This study demonstrated that short-time (1 h) pre-anoxic electro-stimulation significantly enhanced SND efficiency in the aerobic phase by promoting the proliferation of mixotrophic and heterotrophic denitrifiers. SND and TN removal efficiencies at the optimal electric current (EC) (0.02 A) were 85.6 % and 93.9 %, which were 39.1 % and 17.2 % higher than control. Microbial community analysis indicated that the abundance of mixotrophic and heterotrophic denitrifiers significantly increased. H2 generated in the electro-stimulation process induced the proliferation of mixotrophic denitrifiers. The weak EC (0.02 A) promoted the activity and growth of heterotrophic denitrifiers by accelerating electron transfer. They concurrently mediated heterotrophic denitrification to enhance SND efficiency. PICRUSt2 analysis revealed that the abundance of denitrifying genes dramatically surged. This study provides new insights into applying electrolysis to achieve advanced SND while minimizing electricity consumption.

Boron-doped carbon nano dot anchored thin film coating on cobalt vanadium oxide for ultrafast energy storage devices

Lithium-ion capacitors (LICs) with ultrafast rate capabilities are required to increase the applicability of rechargeable energy storage devices. Considering that the power density of an LIC is primarily determined by the anode properties, carbon coating onto the anode material is a promising method of accelerating electron transfer between particles and alleviating structural collapse during repeated charge–discharge cycles. In this study, a new coating configuration featuring a boron-doped carbon nano dot-anchored thin film on cobalt vanadium oxide (BC-CVO) was demonstrated. The coating morphology, wherein the carbon nano dots were connected by a thin carbon film, induced nano-scale surface roughness on CVO, expanding the contact area between the functional groups on the coating layer and electrolyte. The boron-doped carbon lattice structure provided ultrafast electron transfer inside the CVO particles, which allowed reversible electron transfer even under ultrafast charge–discharge cycles. This morphological and chemical combination significantly improved the ultrafast-rate capability of the LIC anodes (429.6 mAh/g at 4000 mA/g and 534.3 mAh/g after 1000 cycles at 2000 mAh/g) compared to that of bare CVO. Furthermore, an LIC full cell fabricated with a BC-CVO anode and an activated carbon cathode showed high energy and power densities.

The enhanced degradation of trichloroethylene in the bioelectrochemical system integrated with iron‑carbon micro-electrolysis

Trichloroethylene (TCE) is one of the most abundant volatile chlorinated hydrocarbons in groundwater which threatens human health and the environment. Utilizing a bioelectrochemical system (BES) to treat TCE is a promising strategy; however, as the ionic strength of the groundwater is low and the extracellular electron transfer of BES is limited, BES degradation of TCE is impeded. In this research, iron and graphite were added to the cathode chamber to form a micro-electrolysis to enhance the degradation of TCE synergistically. The results showed that when the iron and carbon mixture dosage was 70 g/L with the mass ratio (Fe/C) of 1:2 and the initial TCE concentration of 100 mg/L, the degradation efficiency of BES reached 97.8 % at the cathodic potential of −0.3 V (vs.SHE). This was 1.31 times, 1.94 times, and 2.74 times that of Fe/C + open-circuit BES, Fe/C micro-electrolysis, and conventional BES without Fe/C, respectively, which implied that iron‑carbon mediated BES colligated the advantages of microbial degradation and micro-electrolysis, and iron‑carbon provided more electrons and accelerated electron transfer to improve the degradation of TCE significantly. Moreover, through the analysis of the microorganisms of Fe/C + BES, the highest abundances of microorganisms at phylum, class, and genus levels were Proteobacteria, Alphaproteobacteria, and Acetobacterium, respectively. By comparing Fe/C + BES with conventional BES, the addition of iron‑carbon enhanced the microbial diversity and species richness and improved the abundances of Pseudomonas and Geobacter at the genus level. In all, iron‑carbon micro-electrolysis can be integrated with BES to treat TCE and facilitate BES application in the volatile chlorinated hydrocarbon-contaminated sites.

A photoelectrochemical sensor based on polydopamine membrane-coated CdS@C core-shell heterostructure for curcumin detection

Curcumin has been widely employed in various fields, but excessive intake may cause tissue necrosis and pose a serious threat to people’s lives and health. Hence, it is crucial to rapidly and precisely detect the content of curcumin. In present research, CdS@C heterostructure materials were successfully prepared through a one-pot solvothermal reaction strategy, utilizing glucose as the carbon source. Simultaneously, polydopamine thin films (ePDA) were successfully deposited on the surface of CdS@C-modified electrodes by the cyclic voltammetry (CV) method. A photoelectrochemical sensor based on the polydopamine membrane-coated CdS@C core–shell heterostructure (ePDA/CdS@C) was designed for curcumin detection. Furthermore, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible spectrophotometers (UV-vi) techniques were applied to characterize the structure and morphology of the synthesized photoelectric materials. The ePDA coating enhances the stability of the CdS@C material, and the CdS@C core-shell heterostructure accelerates electron transfer. Consequently, the ePDA/CdS@C material generates an outstanding and steady photocurrent response. Under ideal conditions, the novel sensor exhibits a satisfactory linear response to curcumin detection within the concentration range of 0.025–370 μM, with a detection limit as low as 0.0165 μM. Additionally, the ePDA/CdS@C-based photoelectrochemical aptasensor displays remarkable reproducibility, stability, and selectivity. This innovative sensing platform accurately detects curcumin in human serum and urine samples, with an excellent recovery range (99.47 %–103.60 %) and relatively low RSD values (1.49 %–3.56 %). In conclusion, this work offers a novel approach for curcumin detection.

Boosting O2 activation by internal electric field regulation in vacancy-enhanced S-scheme heterojunction for efficient degradation of bisphenol A

The photocatalytic molecular oxygen (O2) activation is hindered by the weak O2 adsorption capacity and obstacles to electron transfer. Herein, a vacancy-enhanced BiOI/g-C3N4 S-scheme heterojunction was designed to enhance the O2 adsorption capacity and accelerate electron transfer in water treatment. The density functional theory calculation (DFT), in-situ irradiation X-ray photoelectron spectroscopy (XPS) spectra and experiments demonstrate that the S-scheme charge transfer mechanism. And the introduction of N vacancies in g-C3N4 can adjust the electronic structure, strengthen the internal electric field in S-scheme heterojunction, thereby broadening the light response range and further improving the separation rate of photoinduced electron-hole pairs. Besides, the presence of N vacancies can function as the active sites for the adsorption of O2 and facilitate the capture of electrons, promoting the generation of superoxide radicals (•O2−). Thanks to the synergistic effect of the S-type charge transfer route with N vacancies in g-C3N4, degradation rate of bisphenol A (BPA) for BCN-680 increases to 0.0433 min−1, which is 1.86 and 10.56 times higher than BiOI and CN-680. This work presents a valuable method for O2 activation through designing the S-scheme heterojunction with abundant active sites by vacancy construction.

Highly efficient removal of 1,1,1-trichloroethane from simulated groundwater by polydopamine-modified iron/polylactic acid/biochar composite coupling with Shewanella oneidensis MR-1

Biochar (BC) loaded with nanoscale zero-valent iron (nZVI) has been extensively used to remove chlorinated hydrocarbons from groundwater through biotic/abiotic reductive dechlorination. However, the rapid deactivation due to surface passivation, hydrophobicity, and inadequacy of carbon sources severely limits its practical application. Herein, a novel polydopamine (PDA)-modified iron/polylactic acid (PLA)/biochar composite (PDA@OBC-nZVI) was successfully synthesized to address this issue. Its effect and mechanism for 1,1,1-trichloroethane (1,1,1-TCA) removal from simulated groundwater coupling with Shewanella oneidensis MR-1 (MR-1) were investigated. Results showed that nZVI and PLA particles were uniformly dispersed on the BC surface, being smoother after PDA coating. The composite coupling with MR-1 exhibited efficient and long-term performances for 1,1,1-TCA removal. Under the experimental conditions comprising 10 % PLA mass fraction in the composite, 10 g·L−1 composite dosage and 20 mL·L−1 MR-1 inoculum volume, 83.14 % of 100 mg·L−1 1,1,1-TCA was removed by PDA@OBC-nZVI + MR-1 within 360 h, compared to only 48.12 % by PDA@OBC-nZVI alone. The primary removal pathways included the rapid chemical reductive dechlorination and the long-term microbial dissimilatory iron reduction. The synergistic dechlorination mechanism was manifested in the composite providing sustained carbon sources, accelerating electron transfer, raising sorbed Fe(II) level, and promoting cytochrome c secretion by MR-1. The novelty of this study is enhancing the hydrophilicity and redox activity of carbon-iron composites by PDA modification for the first time in 1,1,1-TCA removal. Overall, the results suggest that PDA@OBC-nZVI + MR-1 can effectively promote the reductive dechlorination process, being great potential for the remediation of chlorinated hydrocarbon-contaminated groundwater.

Highly sensitive electrochemiluminescence sensing platform based on copper nanoclusters synthesized via a DNA nanoribbon template for the detection of cancer cells

Herein, we presented a simple ultra-sensitive "on-off-on" electrochemiluminescence (ECL) biosensor that uses copper nanoclusters (CuNCs) synthesized via a DNA nanoribbon (DNR) template (DNR-CuNCs) as a sensing platform coupled with target-cycle amplification for the sensitive and rapid detection of cancer cells that overexpress proteins. DNR templated DNR-CuNCs, a well-ordered ECL emitter, was integrated into the nucleic acid framework structure to self-assembly, which enhanced the ECL intensity benefit from reduced band gap and accelerated electron transfer reaction of CuNCs. Additionally, an optimized exonuclease III (Exo III)-assisted cycle amplification method was introduced to efficiently convert trace target biomarkers into a substantial output of DNA, significantly improving target conversion efficiency and boosting the ECL signal. Consequently, MUC1 proteins were sensitively detected by the ECL biosensor throughout a broad concentration range, from 1 fg·mL−1 to 1 ng·mL−1, with a low limit of detection (LOD) of 0.061 fg·mL−1, and successfully detected MUC1-overexpressing cancer cells (using MCF-7 cancer cells as a model), accurately identifying MCF-7 cells in the concentration range of 10–100,000 cells·mL−1 with a LOD of 5 cells·mL−1. This research, for the first time, introduced a DNR-CuNCs ECL biosensor for the highly sensitive detection of living cells and their associated surface proteins. The detection of biomarker proteins and specific cells is greatly promising by applying this simple, sensitive, and specific strategy.

Spatial confined synthesis of submicron Fe-MoS2 with abundant surface cationic groups and sulfur vacancies for enhanced peroxymonosulfate activation

ABSTRACT The widespread use of emerging refractory organic contaminants poses a significant threat to human health, prompting the need for a cost-effective and efficient removal strategy. While the iron ions/PMS system effectively removes organic pollutants, slow Fe3+ to Fe2+ transformation hampers its efficiency, and the homogeneous distribution of iron ions complicates separation, resulting in secondary sludge pollution. Herein, we developed a novel submicron Fe-MoS2 (S-Fe-MoS2) catalyst with abundant surface cationic groups and sulfur vacancy through a cationic polyacrylamide aerogels (CPAMA) confined hydrothermal synthesis strategy. These features promote active site exposure, enhance reactant adsorption, and accelerate electron transfer between Mo and Fe sites, improving catalytic kinetics and promoting Fe3+/Fe2+ cycle for PMS activation. As a result, the S-Fe-MoS2/PMS system exhibited a high catalytic rate constant (k obs) of 0.32 min−1, in the degradation of 4-chlorophenol (4-CP), 1.5 times higher than that of the conventional Fe-MoS2/PMS system. It also achieved 82.9% total organic carbon (TOC) degradation within 60 min. Additionally, it possessed similar degradation performance for various organic pollutants, along with remarkable reusability (four cycles) and broad pH adaptability (2–8), indicating significant potential for widespread application. This study provided a new way for developing advanced heterogeneous catalysts with high efficiency for water treatment.

Synergistic scavenging of sulfamethoxazole and hexavalent chromium in groundwater sample induced by iron-char composites activated persulfate triggering dominant electron transfer process

Effectively scavenging combined pollutants in complex water matrix via dominant electron transfer pathway using modified zero-valent iron (ZVI) remains challenging. Herein, novel iron-based catalysts were synthesized using ball milling and pre-oxidation modified biochar (MOBC), which featured abundant pore structure and oxygen-rich functional moieties to support nZVI in activating persulfate (PS). The most suitable catalytic system achieved ultrafast simultaneous removal of 89.0 % of sulfamethoxazole (SMX) and nearly 100 % of hexavalent chromium (Cr(VI)) within 5 min (with nearly complete removal of SMZ and Cr(VI) in 60 min). By serving as an electron shuttle, MOBC700 could accelerate electron transfer from SMX to PS adsorbed on the nZVI1.0@MOBC700 for SMX decomposition, with reactive oxygen species (ROSs) also contributing. Moreover, nZVI facilitated the reduction of Cr(VI) adsorbed on nZVI1.0@MOBC700 through electron transfer. The dissolved Fe(II) generated via PS activation and Cr(VI) reduction further facilitated Cr(VI) removal from the solution, while the gradual consumption of excess Fe(II) ensured continued ROSs-mediated degradation of SMX. Additionally, the system also demonstrated resistance to interference from NO3-, CO32-, and humic acid, and was effective in remediating four different water samples. Overall, this study presents a promising method for designing iron-char composites to address combined antibiotic and heavy metal contamination in groundwater samples via dominant electron transfer process.

Self-grown non-noble metal Ni2P loaded on CdS effectively accelerates electron transfer to enhance efficient photocatalytic hydrogen evolution

The development of efficient catalysts has attracted widespread attention for the hydrogen evolution reaction of water splitting via MOF derivatives to remediate the current serious environmental and energy problems. Herein, the composite catalyst Ni-MOF/Ni2P/CdS was effectively created by calcination and hydrothermal methods using Ni-MOF and CdS as raw materials. The findings demonstrated that the composite catalyst NPS-15 with the highest photocatalytic hydrogen evolution rate (18.359 mmol/g/h) was successfully developed, which is nine times greater than the hydrogen evolution rate of pure CdS and 80 times higher than that of Ni-MOF. In addition, its catalytic stability can still be maintained at about 80 % after 25 h of experience. This can be attributed to the presence of Ni2P, which improves the visible light absorption ability of the composite and promotes more photogenerated electron production. The characterization results have demonstrated that Ni2P as an electron trapping center can significantly improve the separation efficiency and transfer ability of photogenerated carriers. Meanwhile, Ni2P contains a negatively charged P, which can attract more protons to bind electrons for the reduction reaction. This study provides a probable strategy for the development of high-performance photocatalytic MOF derivatives for applications involving sustainable energy conversion.

Microenvironment Tailoring of NiCo Alloys Coupled with FePc as Efficient Bifunctional Catalysts for High-Rate Zn-Air Batteries.

The practical application of Zn-air batteries require exploring cost-effective and durable bifunctional electrocatalysts. However, the simultaneous preparation of catalysts with bifunctional activities for oxygen reduction reaction (ORR) and oxygen precipitation reaction (OER) remains challenging. Herein, we synthesized a novel hybrid catalyst (FePc/NiCo/CNT), which couples NiCo alloy with FePc through electrostatic interaction. The interaction between FePc and NiCo alloy can enhance the intrinsic catalytic activity of the active site Fe-N4 and prevent the electrolyte corrosion of the metal alloy, ultimately improving the stability of the catalyst by the microenvironment-tailoring strategy. The resultant FePc/NiCo/CNT catalyst exhibits outstanding oxygen reduction reaction (ORR) activity with a half-wave potential of 0.88 V, which is attributed to the abundant Fe-Nx active sites. Furthermore, the electron interactions between NiCo/CNT and FePc accelerate electron transfer and enhance the activation of oxygen intermediates, consequently boosting the OER activity with an overpotential of 260 mV at 10 mA cm-2. The Zn-air batteries assembled with FePc/NiCo/CNT show a high power density of 175.1 mW cm-2 and excellent cycling stability for up to 430 h at 20 mA cm-2. The preparation of oxygen electrode catalysts for renewable clean energy devices can be made more convenient with this directly engineered strategy for ORR and OER active centers.

Performances of a novel BAF with ferromanganese oxide modified biochar (FMBC) as the carriers for treating antibiotics, nitrogen and phosphorus in aquaculture wastewater.

In this paper, a biological aerated filter (BAF) based on ferromanganese oxide-biochar (FMBC) was constructed to investigated the removal performance and mechanism for conventional pollutants and four kinds of antibiotic, in contrast of conventional zeolite loaded BAF (BAF-A) and bamboo biochar filled BAF (BAF-B). Results showed that the average removal efficiency of total nitrogen (TN), total phosphorus (TP) and antibiotics in a FMBC-BAF (named by BAF-C) were 52.97 ± 2.27%, 51.58 ± 1.92% and 70.36 ± 1.00% ~ 81.65 ± 0.99% respectively in running period (39-100 d), which were significantly higher than those of BAF-A and BAF-B. In the BAF-C, the expression of denitrification enzyme activities and the secretion of extracellular polymeric substance (EPS) especially polyprotein (PN) were effectively stimulated, as well as accelerated electron transfer activity (ETSA) and lower electrochemical impedance spectroscopy (EIS) were acquired. After 100 days of operation, the abundance of nitrogen, phosphorus and antibiotic removal functional bacteria like Sphingorhabdus (4.52%), Bradyrhizobium (1.98%), Hyphomicrobium (2.49%), Ferruginibacter (7.80%), unclassified_f_Blastoca tellaceae (1.84%), norank_f_JG30-KF-CM45 (6.82%), norank_f_norank_o_SBR1031 (2.43%), Nitrospira (2.58%) norank_f_Caldilineaceae (1.53%) and Micropruina (1.11%) were enriched. Mechanism hypothesis of enhanced performances of nutrients and antibiotics removal pointed that: The phosphorus was removed by adsorption and precipitation, antibiotics removal was mainly achieved through the combined action of adsorption and biodegradation, while nitrogen removal was realized by biologic nitrification and denitrification in a FMBC-BAF for aquaculture wastewater treatment.

Microwave-induced dual-responsive spinel (CoxMn1-xFe2O4) target-triggered non-radical pathways of peroxymonosulfate: Superexchange interaction and synergistic mechanism

The efficient activation of peroxymonosulfate (PMS) and the directional selection of oxidation pathways are crucial for achieving efficient pollutant removal in advanced oxidation processes (AOPs). A composite activation method of a microwave-induced dual-responsive catalyst (Co0.4Mn0.6Fe2O4) with both dielectric and catalytic properties is proposed to successfully trigger the non-radical pathway of PMS for 100 % removal of pharmaceutical pollutant (diatrizoate, DTZ) in 6 min, which shows good resistance to environmental interference and cyclic stability, and lower electrical energy requirement. 1O2 and surface-bound reactive oxygen species (ROS) are the main ROSs responsible for non-radical oxidation, with a total contribution of 98 %. The superexchange effect of Co-Mn (Mn3++Co3+→Mn4++Co2+) induces the electron delocalization of Mn site, which promotes the adsorption of PMS, interfacial charge transfer, and surface-bound ROS generation. The "thermal and non-thermal" effects of microwaves accelerate electron transfer and 1O2 generation to further trigger non-radical pathways. This work provides new strategies for bifunctional catalyst design and directional triggering of non-radical pathways of PMS-AOPs.

Graphdiyne-Induced CoN/CoS2 Heterojunction: Boosting Efficiency for Bifunctional Oxygen Electrochemistry in Zinc-Air Batteries.

The performance of zinc-air battery is constrained by the sluggish rate of oxygen electrode reaction, particularly under high current discharge conditions where the kinetic process of the oxygen reduction reaction (ORR) decelerates significantly. To address this challenge, we present a novel phase transition strategy that facilitates the creation of a heteroatom-doped heterointerface (CoN/CoS2). The meticulously engineered CoN/CoS2/NC electrocatalyst displays a superior ORR half-wave potential of 0.87 V and an OER overpotential of 320 mV at 10 mA cm-2. Experimental and computational analysis confirm that the CoN/CoS2 heterostructure optimizes local charge distribution, accelerates electron transfer, and tunes active sites for enhanced catalysis. Notably, this heterojunction improves stability by resisting corrosion and degradation under harsh alkaline conditions, thus demonstrating superior performance and longevity in a custom-made liquid zinc-air battery. This research provides valuable practical and theoretical foundations for designing efficient heterointerfaces in electrocatalysis applications.

Enhanced mineralization of nitrophenols by a novel C@ZVAl-PS based sequential reduction-oxidation process

Widely employed nitrophenols (NPs) are refractory and antioxidant due to their strong electron-withdrawing group (-NO2). Actually, NPs are readily reduced to aminophenols (APs). However, APs remain toxic and necessitate further treatment. Herein, we utilized a novel sequential reduction-oxidation system of carbon-modified zero-valent aluminum (C@ZVAl) combined with persulfate (PS) for the thorough removal of both NPs and APs. The results demonstrated that p-nitrophenol (PNP, up to 1000 mg/L) exhibited complete reduction to p-aminophenol (PAP), and then over 98.0 % of PAP could be effectively oxidized, in the meantime the removal rate of chemical oxygen demand (COD) was as high as 95.9 %. Based on the SEM and XPS characterizations, we found that C@ZVAl has exceptionally high reactivity that generates massive electrons and reduces PNP to PAP through accelerated electron transfer. In the subsequent oxidation step, PS can be rapidly activated by C@ZVAl to generate SO4− radicals for PAP oxidization. Meanwhile, the mineralization of COD proceeds. The temporal binding of reduction and oxidation can be regulated by varying the PS dosing time. Namely, the appropriate delay in PS dosing facilitates sufficient reduction to provide enough reactants for oxidation, favoring the mineralization of PNP and COD. More crucially, dinitrodiazophenol (DDNP) in an actual explosive wastewater without any pretreatment can be effectively mineralized by this sequential reduction-oxidation system, affirming the excellent performance of this process in practical applications. In conclusion, the C@ZVAl-PS based sequential reduction-oxidation looks very promising for enhanced mineralization of nitro-substituted organic contaminants.

Asymmetric Hydrogel Electrolyte Featuring a Customized Anode and Cathode Interfacial Chemistry for Advanced Zn-I2 Batteries.

An integrated asymmetric hydrogel electrolyte with a tailored composition and chemical structure on the cathode/anode-electrolyte interface is designed to boost the cost-effective, high-energy Zn-I2 battery. Such a configuration concurrently addresses the parasitic reactions on the Zn anode side and the polyiodide shuttle issue afflicting the cathode. Specifically, the Zn2+-cross-linked sodium alginate and carrageenan dual network (Carra-Zn-Alg) is adopted to guide the Zn2+ transport, achieving a dendrite-free morphology on the Zn surface and ensuring long-term stability. For the cathode side, the poly(vinyl alcohol)-strengthened poly(3,4-ethylenedioxythiophene)polystyrenesulfonate hydrogel (PVA-PEDOT) with high conductivity is employed to trap polyiodide and accelerate electron transfer for mitigating the shuttle effect and facilitating I2/I- redox kinetics. Attributing to the asymmetrical architecture with a customized interfacial chemistry, the optimized Zn-I2 cell exhibits a superior Coulombic efficiency of 99.84% with a negligible capacity degradation at 0.1 A g-1 and an enhanced stability of 10 000 cycles at 5 A g-1. The proposed asymmetric hydrogel provides a promising route to simultaneously resolve the distinct challenges encountered by the cathode and anode interfaces in rechargeable batteries.

Three‐dimensional carbon nanotube framework enables low‐cost LiFe5O8 anode material for high‐performance lithium‐ion batteries

LiFe5O8 is regarded as a promising material, which is used as anode for lithium‐ion batteries on account of its lower cost and higher theoretical capacity. However, its practical applications are hindered by the low electron transfer rate, poor cycling performance, and huge magnification of lattice volume. In this work, a LiFe5O8/carbon nanotubes (CNTs) composite anode is designed to realize the ideal anode for low‐cost lithium‐ion batteries, showing broad commercial application prospects. It is found that the three‐dimensional conductive network of CNTs is used to accelerate electron transfer rate within the LiFe5O8 particles, thereby significantly reducing the reversible reaction barrier (Fe/Fe3O4). In addition, it can also alleviate the volume change of electrode, which maintains a stable Li+ insertion/extraction behavior during long‐term cycles. As a consequence, there is still a high capacity (427.3 mAh g−1) of the LiFe5O8/CNTs 3% anode reserved after 50 cycles at 0.5 C whereas the bare LiFe5O8 anode only delivers a low capacity of 220.6 mAh g−1 along with a poor cycling stability. This work highlights the outstanding contribution of electronic conductivity toward the electrochemical performance of LiFe5O8 anode and provides a low‐cost and commercially applicable composite anode for developing lower cost lithium‐ion batteries.

S vacancy in n-n type heterojunction accelerate electron transfer, improve the photocatalytic activity of CO2RR and H2 evolution

The introduction of anionic vacancies is a promising strategy to improve the photocatalytic activity of catalysts, however, the introduction of sulfur vacancy defects at the interface of heterojunction is a challenging task. Therefore, in this work, a secondary hydrothermal method was used to generate sulfur vacancy defects (Vs) at the interface of CdS/MoS2 heterojunction (Vs-CdS/MoS2), which was applied to photocatalytic reduction of CO2 and hydrogen evolution. The CO yield of the prepared CM-7 sample was 3.1 times higher than that of pristine CdS, and the H2 yield was 10.2 times higher. Experimental analysis showed that sulfur vacancies were detected on the (002) crystal surface of CdS in the heterojunction, providing active sites, redistributing the local charge, lowering the charge transport resistance and carrier complexation rate, and increasing the carrier migration rate, which led to the improvement of the photocatalytic activity. This work provides a novel strategy for designing heterojunctions with defect engineering applied to photocatalytic reduction of CO2 and hydrogen evolution.