Interfacial Electron Transfer Research Articles

Regulating sulfur vacancies formation on mechanochemically modified pyrite to steer non-radical molecular oxygen activation for water purification

Ubiquitous pyrite (FeS2) in the earth’s crust features strong reducing capacity, presenting a promising alternative for molecular oxygen (O2) activation to facilitate water purification, but the interfacial electron transfer efficiency was remarkably retarded due to the existed passivation layer and limited reactive sites on the surface of pristine pyrite. Herein, we proposed an effective mechanochemical approach to unlock the potential of pyrite for O2 activation and refractory pollutant degradation. Compared to the inert pristine one, the ball milling-treated pyrite (BMPs) could achieve efficient sulfamethoxazole (SMX) degradation with a rate constant of 0.23 h−1. By a combination of characterizations, batch experiments, and density function theory (DFT) calculations, a clear panorama delineated the consecutive O2 adsorption and activation processes was established. Ball milling treatment could import rich sulfur vacancies (SVs) on pyrite, which unshifted the p-band center of adjacent S for improved O2 adsorption, also narrowed the band gap of BMPs to promote the interfacial electron transfer rate for O2 activation. Singlet oxygen (1O2) was identified as the dominant reactive species for SMX degradation, such non-radical oxidation feature rendered the system with remarkable activity and environmental robustness. Our work lay a foundation for constructing robust pyrite towards stable and efficient environmental remediation applications.

Surface‐Grafted Single‐Atomic Pt−Nx Complex with a Precisely Regulating Coordination Sphere for Efficient Electron Acceptor‐Inducing Interfacial Electron Transfer

AbstractBased on the electron‐withdrawing effect of the Pt(bpy)Cl2 molecule, a simple post‐modification amide reaction was firstly used to graft it onto the surface of NH2‐MIL‐125, which performed as a highly efficient electron acceptor that induced the conversion of the photoinduced charge migration pathway from internal BDC→TiOx migration to external BDC→PtNx migration, significantly improving the efficiency of photoinduced electron transfer and separation. Furthermore, precisely regulating over the first coordination sphere of Pt single atoms was achieved using further post‐modification with additional bipyridine to investigate the effect of Pt−Nx coordination numbers on reaction activity. The as‐synthesized NML‐PtN2 exhibited superior photocatalytic hydrogen evolution activity of 7.608 mmol g−1 h−1, a remarkable improvement of 225 and 2.26 times compared to pristine NH2‐MIL‐125 and NML‐PtN4, respectively. In addition, the superior apparent quantum yield of 4.01 % (390 nm) and turnover frequency of 190.3 h−1 (0.78 wt % Pt SA; 129 times compared to Pt nanoparticles/NML) revealed the high solar utilization efficiency and hydrogen evolution activity of the material. And macroscopic color changes caused by the transition of carrier migration paths was first observed. It holds profound significance for the design of MOF‐Molecule catalysts with efficient charge carrier separation and precise regulation of single‐atom coordination sphere.

Surface-Grafted Single-Atomic Pt-Nx Complex with a Precisely Regulating Coordination Sphere for Efficient Electron Acceptor-Inducing Interfacial Electron Transfer.

Based on the electron-withdrawing effect of the Pt(bpy)Cl2 molecule, a simple post-modification amide reaction was firstly used to graft it onto the surface of NH2-MIL-125, which performed as a highly efficient electron acceptor that induced the conversion of the photoinduced charge migration pathway from internal BDC→TiOx migration to external BDC→PtNx migration, significantly improving the efficiency of photoinduced electron transfer and separation. Furthermore, precisely regulating over the first coordination sphere of Pt single atoms was achieved using further post-modification with additional bipyridine to investigate the effect of Pt-Nx coordination numbers on reaction activity. The as-synthesized NML-PtN2 exhibited superior photocatalytic hydrogen evolution activity of 7.608 mmol g-1 h-1, a remarkable improvement of 225 and 2.26 times compared to pristine NH2-MIL-125 and NML-PtN4, respectively. In addition, the superior apparent quantum yield of 4.01 % (390 nm) and turnover frequency of 190.3 h-1 (0.78 wt % Pt SA; 129 times compared to Pt nanoparticles/NML) revealed the high solar utilization efficiency and hydrogen evolution activity of the material. And macroscopic color changes caused by the transition of carrier migration paths was first observed. It holds profound significance for the design of MOF-Molecule catalysts with efficient charge carrier separation and precise regulation of single-atom coordination sphere.

Electrochemically-induced metal–oxygen bond Cu(II)-[rad]SO5− on novel CuBi2O4 anode for efficient peroxymonosulfate activation

Transition metal oxide catalysts had the limitation of a slow electron transfer rate in activating peroxymonosulfate (PMS) during wastewater treatment. In this work, we developed a novel copper bismuthate (CuBi2O4) anode using a catalyst drop casting method to efficiently activate PMS through electrochemically induced metal–oxygen bonds for herbicide prometon (PMT) degradation. The PMT removal rate in the EC/CuBi2O4 anode/PMS system was 74.60 %, which was much greater than the simple superposition of CuBi2O4 catalyst-activated PMS alone (4.88 %) and FTO anode electrically activated PMS (32.15 %). The CuBi2O4 fixed on the anode surface accelerated the electron transfer efficiency between the interface employing the electric field, showing stronger PMS activation performance than the equivalent three-dimensional particle electrode system. The free radical quenching experiments illustrated that the degradation of PMT mainly proceeded through the free radical oxidation pathway dominated by SO4− and OH. In the EC/CuBi2O4 anode/PMS system, the traditional Cu+/Cu2+ cycle did not dominate the activation of PMS in the CuBi2O4 anode reaction. Raman experiment and open circuit potential results proved that the introduction of an electric field caused PMS to form the metal–oxygen bond Cu(II)-SO5− at the CuBi2O4 anode interface, and converted it into activated state PMS (PMS*), accelerating the interface electron transfer. The PMS* was more readily further activated by electrons and promoted water dissociation to form OH for pollutants degradation. The EC/CuBi2O4 anode/PMS system manifested stable purification performance for COD and emerging pollutants in high-salt pesticide wastewater, coupled with its superior economic benefits, possessing broad application prospects.

Anchoring Pt nanoparticle onto monolayer VS2 nanosheets boost efficient acidic hydrogen evolution

The electrocatalytic hydrogen evolution reaction (HER) is a key technology for hydrogen production and plays a significant role in advancing sustainable energy conversion. This study successfully anchored platinum (Pt) nanoparticles onto monolayer VS2 nanosheets via a colloidal chemistry method to enhance their HER performance under acidic conditions. The monolayer VS2 nanosheets provide a stable substrate, with their large surface area and high in-plane electrical conductivity effectively enhancing the interfacial electron transfer and electrochemical contact of the Pt nanoparticles. The Pt/VS2 composite material significantly reduces the energy barrier required for HER and enhances electrochemical activity, while also lowering the cost of the catalyst. At a current density of 10 mA cm−2, the composite material with Pt nanoparticles anchored onto VS2 nanosheets achieved an overpotential of just 26 mV and exhibited a high mass activity of 23.7 A/mgPt. Density functional theory (DFT) calculations and experimental analyses further elucidated the critical role of interfacial electronic effects and sulfur vacancy modulation in enhancing catalytic efficiency. These findings highlight the potential of interface engineering to control electronic structure and sulfur vacancies, significantly enhancing the hydrogen production efficiency and cost-effectiveness of Pt-based catalysts even at low Pt loadings under acidic conditions.

Promotion of direct electron transfer between Shewanella putrefaciens CN32 and carbon fiber electrodes via in situ growth of α-Fe2O3 nanoarray

The iron transport system plays a crucial role in the extracellular electron transfer process of Shewanella sp. In this study, we fabricated a vertically oriented α-Fe2O3 nanoarray on carbon cloth to enhance interfacial electron transfer in Shewanella putrefaciens CN32 microbial fuel cells. The incorporation of the α-Fe2O3 nanoarray not only resulted in a slight increase in flavin content but also significantly enhanced biofilm loading, leading to an eight-fold higher maximum power density compared to plain carbon cloth. Through expression level analyses of electron transfer-related genes in the outer membrane and core genes in the iron transport system, we propose that the α-Fe2O3 nanoarray can serve as an electron mediator, facilitating direct electron transfer between the bacteria and electrodes. This finding provides important insights into the potential application of iron-containing oxide electrodes in the design of microbial fuel cells and other bioelectrochemical systems, highlighting the role of α-Fe2O3 in promoting direct electron transfer.

Hydrogen bond-assisted construction of MOF/semiconductor heterojunction photocatalysts for highly efficient electron transfer

It remains challenging for the fabrication of metal-organic framework (MOF)/semiconductor heterojunction photocatalysts with close contact interfaces. In this work, a novel MOF/semiconductor heterojunction photocatalyst consisting of H2O2-modified TiO2 nanotubes (H2O2-TNTs) and MIL-88B(Fe)-NH2 (labeled as H-T/M) was firstly constructed based on the hydrogen-bonded combination between the O atoms from –OOH groups resulting from H2O2 absorbed on the surface of TiO2 nanotubes and the H atoms of the –NH2 group in MOF. The significantly enhanced photocatalytic property of the H-T/M heterojunction for reducing Cr(VI) could be ascribed to the accelerated interfacial electron transfer dynamics by a channel of hydrogen bonds (N···H–O–O–Ti), which could be extracted from the femtosecond transient absorption spectroscopy (fs-TAS). Moreover, the built-in electric field and the differences in charge density based on density functional theory (DFT) calculations could provide the driving force for charge transfer.

Boosting photo-thermal co-catalysis CO2 methanation by tuning interface electron transfer via Mott-Schottky heterojunction effect

Photo-thermal co-catalytic reduction of CO2 to synthesize value-added chemicals presents a promising approach to addressing environmental issues. Nevertheless, traditional catalysts exhibit low light utilization efficiency, leading to the generation of a reduced number of electron-hole pairs and rapid recombination, thereby limiting catalytic performance enhancement. Herein, a Mott-Schottky heterojunction catalyst was developed by incorporating nitrogen-doped carbon coated TiO2 supported nickel (Ni) nanometallic particles (Ni/x-TiO2@NC). The optimal Ni/0.5-TiO2@NC sample displayed a conversion rate of 71.6 % and a methane (CH4) production rate of 65.3 mmol/(gcat·h) during photo-thermal co-catalytic CO2 methanation under full-spectrum illumination, with a CH4 selectivity exceeding 99.6 %. The catalyst demonstrates good stability as it shows no decay after two reaction cycles. The Mott-Schottky heterojunction catalysts display excellent efficiency in separating photo-generated electron-hole pairs and elevate the catalysts’ temperature, thus accelerating the reaction rate. The in-situ experiments revealed that light-induced electron transfer effectively facilitates H2 dissociation and enhances surface defects, thereby promoting CO2 adsorption. This study introduces a novel approach for developing photo-thermal catalysts for CO2 reduction, aiming to enhance solar energy utilization and facilitate interface electron transfer.

Multifunctional MoS2 membrane for integrated solar-driven water evaporation and water purification

Solar-driven interfacial water evaporation shows great potential to address the global water crisis, but its efficient implementation in the presence of organic wastewater remains challenging. Here, we achieved integrated water evaporation and organic compound degradation by designing a multifunctional MoS2 membrane. Under 1.0 sun irradiation, the membrane exhibits an evaporation rate of 2.07 kg m−2 h−1 and 82% degradation efficiency of organic pollutants, with negligible organic pollutant residues in the condensate. The high performance is attributed to the thermal energy generated by the evaporation process of MoS2 membrane. This promotes an increase in the rate constant of interfacial electron transfer during the photocatalytic reaction, accelerating the generation of free radicals and facilitating the removal of organic pollutants. The study demonstrated that fresh water can be collected from high-salinity wastewater at a rate of 1.56 kg m−2 h−1. The MoS2 membrane provides a sustainable approach to addressing the water crisis.

Ultrafast electron transfer at the In2O3/Nb2O5 S-scheme interface for CO2 photoreduction

Constructing S-scheme heterojunctions proves proficient in achieving the spatial separation of potent photogenerated charge carriers for their participation in photoreactions. Nonetheless, the restricted contact areas between two phases within S-scheme heterostructures lead to inefficient interfacial charge transport, resulting in low photocatalytic efficiency from a kinetic perspective. Here, In2O3/Nb2O5 S-scheme heterojunctions are fabricated through a straightforward one-step electrospinning technique, enabling intimate contact between the two phases and thereby fostering ultrafast interfacial electron transfer (<10 ps), as analyzed via femtosecond transient absorption spectroscopy. As a result, powerful photo-electrons and holes accumulate in the Nb2O5 conduction band and In2O3 valence band, respectively, exhibiting extended long lifetimes and facilitating their involvement in subsequent photoreactions. Combined with the efficient chemisorption and activation of stable CO2 on the Nb2O5, the resulting In2O3/Nb2O5 hybrid nanofibers demonstrate improved photocatalytic performance for CO2 conversion.

Exploring electron transfer: Bioinspired, biomimetics, and bioelectrochemical systems for sustainable energy and Value-Added compound synthesis

Electron transfer (ET) is a fundamental process that underlies various phenomena in physics, chemistry, and biology. Understanding ET mechanisms is crucial for developing sustainable energy solutions and synthesizing value-added compounds efficiently. In this context, the present review provides the fundamental aspects of ET involving bioinspired, biomimetics, and biological entities and its significance for sustainable energy and green electrosynthesis fields. Among the theoretical and experimental cornerstones, Marcus Theory, electronic conductance, computational modeling, biomolecular thermodynamics, electrochemical and kinetic theories, protein film voltammetry, and the emergence of in situ and operando techniques are explored. Theoretical modeling is vital for understanding and predicting ET processes. Additionally, the significance of experimental techniques for investigating the ET process in biological entities and interfaces is discussed. Protein film voltammetry is a valuable and consolidated technique for studying ET processes at the protein-electrode interface, whereas in situ and operando techniques for interrogating ET processes in real time provide insights into the dynamics and mechanisms of ET. The concept of quantum conductance in biological structures is addressed, evidencing a trend and power of single-entity analysis. Aspects of extracellular and interfacial ET processes are presented and discussed in the electrochemical energy conversion systems. A deep understanding of these processes can improve the design of efficient bioinspired catalysts. Therefore, this multidisciplinary work aims to fill the gaps between different scientific fields related to ET involving bioentities to develop innovative energy and value-added compound synthesis solutions.

Dual surface defects induced efficient interfacial electron transfer in S-scheme hollow ZnO@ZnS heterojunction for uranium (VI) removal

Photocatalytic reduction is a promising way to remove radioactive uranium U(VI) in wastewater. Herein, an S-scheme ZnO@ZnS heterojunction with hollow structure and dual-vacancies of Zn and S (ZnV, SV) is developed. The hollow confined space enhances light trapping ability through multiple light scattering and reflection, while the existence of vacancies extends light absorption, further enhancing the utilization of solar spectrum. Furthermore, the density function theory (DFT) calculations demonstrate that co-sharing of metal atoms at the interface and the ZnV and SV dual-vacancies induce enhanced internal electric field (IEF), leading to facilitated S-scheme charge transfer, thereby resulting in improved retention of redox potential and suppressed carrier recombination dynamics. ZnO@ZnS shows a highest U(VI) removal rate of 96.48% along with a highest U enrichment of 514.33 mg/g, which is 3.6 and 2.7-folds enhanced compared to pristine ZnO and ZnS, respectively. Through various quenching experiments, a potential new mechanism for the catalytic reduction of U(VI) is proposed. Our findings reveal the involvement of h+ in the reaction, highlighting its significant catalytic role in the reduction process. Moreover, ZnO@ZnS performs excellent U(VI) extraction ability in open-air conditions without any sacrificial agents, revealing the great significance for practical applications.

Modulation of electronic structure of Ni3S2 via Fe and Mo co-doping to enhance the bifunctional electrocatalytic activities for HER and OER

Heazlewoodite nickel sulfide (Ni3S2) is advocated as a promising nonnoble catalyst for electrochemical water splitting because of its unique structure configuration and high conductivity. However, the low active sites and strong sulfur–hydrogen bonds (S–Hads) formed on Ni3S2 surface greatly inhibit the desorption of Hads and reduce the hydrogen and oxygen evolution reaction (HER and OER) activity. Doping is a valid strategy to stimulate the intrinsic catalytic activity of pristine Ni3S2 via modifying the active site. Herein, the Ni foam supported Fe and Mo co-doped Ni3S2 electrocatalysts (Fe-MoS2/Ni3S2@NF) have been constructed using Keplerate polyoxomolybdate {Mo72F30} as precursor through a facile hydrothermal process. Experimental results certificate that Fe and Mo co-doping can effectively tune the local electronic structure, facilitate the interfacial electron transfer, and improve the intrinsic activity. Consequently, the Fe-MoS2/Ni3S2@NF display more excellent HER and OER activity than MoS2/Ni3S2@NF and bare Ni3S2@NF by delivering the 10 and 50 mA cm−2 current densities at ultra-low overpotentials of 74/175 and 80/160 mV for HER and OER. Moreover, when coupled in an alkaline electrolyzer, Fe-MoS2/Ni3S2@NF approached the current of 10 mA cm−2 under a cell voltage of 1.60 V and exhibit excellent stability. The strategy to realize tunable catalytic behaviors via foreign metal doping provides a new avenue to optimize the water splitting catalysts.

Electrochemical insertion of Ni2+ to synthesize Ca-doped β-NiV3O8 films as electrodes for sodium-ion batteries

Sodium-ion batteries (SIBs) need to address inherent limitations such as low energy densities and poor cycle stability. In the paper, a novel yet safe electrochemical method has been employed to insert Ni2+ in pre-prepared films, culminating in the synthesis of Ca-doped β-NiV3O8. The high covalency of the Ni–O bond was expected to enhance the migration rate of Na+, and in turn exhibit a higher ionic conductivity. Various doping amounts of Ca2+ were applied to investigate the differences in the kinetic behavior of β-NiV3O8 film electrodes. Throughout the discharge process, the average DNa+ of Ca-doped β-NiV3O8 was calculated to be 10−13～10−12 cm2 s−1. In addition, high-resolution transmission electron microscopy (HRTEM) and ex-situ X-ray photoelectron spectroscopy (XPS) revealed the presence of oxygen defects, which assisted interfacial electron transfer. Ex-situ X-ray diffraction (XRD) revealed partial new phases (NaV3O8·xH2O and NaVO3·1.9H2O) generation alongside diverse mechanisms of sodium ion insertion/extraction. Under a lower current density with 1 M NaClO4/PC as the electrolyte, it exhibited an initial discharge capacity of 433.2 mA h m−2 at 167 mA m−2 and 96.3 % capacity retention after 100 cycles. This electrochemical method, applicable to treating film electrodes, provides a novel idea for the preparation of high-performance electrode materials for SIBs.

Ultra-fast catalytic oxidation of persulfate by waste fiber carbon with lattice distortion

Every year, a staggering 920,000 tons of chemical fiber textiles are discarded globally, presenting a pressing global challenge of how to extract their high-value utility. This research is dedicated to recovering carbon from waste chemical fiber textiles for catalytic oxidation and degradation of pharmaceutical intermediates in wastewater. Through the interaction of sulfonation and nitrogen doping, a synthetic fiber known as nitrogen-sulfonated doped carbon (SNBC) was skillfully synthesized, resulting in lattice distortion that effectively regulates the p-band center of the catalyst. The result was a significant increase in the interfacial electron transfer rate, which increased the surface electron transfer rate and catalytic removal rate of bisphenol AF by more than 6 times, while greatly reducing the number of oxidants required. This study provides an efficient method for the resource utilization of waste synthetic fiber textiles, which has the characteristics of low energy consumption and high economic benefit.

Degradation of clofibric acid by ozonation assisted by Co-Ce-SBA-15: Role of interfacial electron migration

Restrained by the sluggish Ce redox cycle, Ce-SBA-15 exhibited the low electron transfer toward O3 activation. To this end, cobalt‑cerium co-doped SBA-15 with three-dimensional pore structure was designed using urea-assisted hydrothermal method and its activity was evaluated using Clofibric acid (CA) as target pollutant. XRD and N2 adsorption-desorption characterizations suggested that Co-Ce-SBA-15 possessed a three-dimensional pore structure with high order degree. py-FTIR, O2-TPD, H2-TPR, and in situ electrochemical characterizations indicated that compared with Ce-SBA-15 and Co-SBA-15, Co-Ce-SBA-15 had greater Lewis acid strength, electron transfer ability and oxygen reducibility. Co-Ce-SBA-15/O3 achieved the greater CA removal and mineralization rate, with 98.7 % CA removal and 58.3 % TOC removal were obtained in 90 min. Co-Ce-SBA-15/O3 process would be inhibited by the coexisting Cl−, NO3− and SO42−. Co-Ce-SBA-15 demonstrated the greater ozone utilization rate than those of monometallic SBA-15. Lewis acidic sites of Co and Ce were the main sites for activating O3. DFT results suggested that the obvious electron transfer existed among O3, Co and Ce Lewis acid sites. The conversion of Co3+/Co2+ and Ce4+/Ce3+ accelerated the interfacial electron transfer, which favored for conveying O3 into •OH. •OH was the primary reactive oxygen species involved in degrading CA. 8 kinds of intermediates were found during CA degradation and the possible degradation route was proposed. This study deepened the understanding of the cooperative effect of Co and Ce in catalytic ozonation process.

Dual signal amplification strategy for enhancing Eu2Sn2O7 electrochemiluminescence immunosensor for the sensitive detection of N-terminal pro-brain natriuretic peptide

Pyrochlore oxide Eu2Sn2O7, an electrochemiluminescence (ECL) emitter, exhibits favorable characteristics such as low toxicity, good stability, and abundant electron vacancies. In this work, the interfacial electron transfer efficiency of Eu2Sn2O7 was significantly enhanced through the in situ surface modification with silver nanoparticles (AgNP). Moreover, we introduced a dual signal-amplification strategy involving AgNP and H2O2. The AgNP as a co-reaction catalyst facilitated the reduction of the co-reactant K2S2O8. The OH• generated through H2O2 reduction on the electrode surface induced the decomposition of K2S2O8 to SO4•−. The MoS2-PEI-AuNP (PEI: polyethylenimine) composite was selected as an ideal substrate. A highly sensitive ECL immunosensor based on Eu2Sn2O7-Ag and MoS2-PEI-AuNP was constructed to detect N-terminal pro-brain natriuretic peptide (NT-proBNP). Under the optimized experimental conditions, the ECL immunosensor demonstrated a linear range of 10 fg·mL−1–50 ng·mL−1, with a detection limit of 2.9 fg·mL−1, and showed excellent stability and specificity. The results demonstrate the potential of the ECL immunosensor for clinical diagnosis applications.

A comparative analysis of square-wave voltammetry and multi-frequency electrochemical Faradaic spectroscopy for kinetic characterisation

A rigorous comparison between square-wave voltammetry (SWV) and the recently proposed multi-frequency electrochemical Faradaic spectroscopy (MEFS) is presented for both a quasireversible electrode reaction of a dissolved redox couple at a planar macroscopic electrode and a catalytic regenerative electrode mechanism (EC′ reaction scheme) by means of numerical simulations. MEFS offers fast kinetic characterisation with a minimal set of experiments, as the system is interrogated with a range of SW frequencies in a single experiment. By changing the mid-potential Em, a critical parameter of MEFS, a broad range of standard rate constants for the heterogeneous interfacial electron transfer is accessible, ranging between 0.006 and 0.12 cm s−1. In the case of the EC′ mechanism, features of the current components in both SWV and MEFS reflect the involvement of the follow-up regenerative chemical reaction (i.e. C′ catalytic step). However, for the kinetic characterisation of the EC′ mechanism, the comparative analysis suggests that SWV should be the main operating technique.

Manipulating singlet oxygen generation on Co nanoclusters-confined g-C3N4 macroscopic beads for boosted water decontamination

Reducing the migration distance of reactive oxygen species (ROS) and enhancing interfacial electron transfer represent effective approaches for enhancing the reactivity of heterogeneous catalysts, albeit still posing significant challenges. Herein, we successfully synthesized ultrasmall cobalt nanoclusters-confined g-C3N4 macroscopic beads with N-doped carbon dots (Co/NC@CN beads). Compared to unconfined Co/C and Co/C@CN beads, Co/NC@CN beads demonstrated remarkable utilization efficiency of PMS (84.3%), achieving complete degradation of TC within 20 min at a rate of 162.1 min-1·M-1, surpassing most reported catalysts. Besides, Co/NC@CN beads predominantly generated singlet oxygen (1O2), ensuring efficient removal of micropollutants with resistance to pH and complex water bodies. Experiments have proven that the strong interaction between Co clusters and g-C3N4 beads containing NC dots facilitated the generation of interfacial electron transfer by optimizing the electronic structure of Co nanoclusters, thereby Co/NC@CN beads could capture electrons from tetracycline (TC) and PMS molecules towards dissolved oxygen (DO) to form O2·-, which subsequently converted into 1O2. More importantly, the efficiency of the flow-through unit in the continuous degradation of TC with zero discharge was substantiated by long-term experiments, and its performance could be restored through a straightforward low-temperature carbonization process. This study offers a universal design framework for the creation of various confined macroscopic beads, enabling the achievement of highly effective wastewater treatment.

Efficient removal of bisphenol A from water using a novel organic–inorganic hybrid heterojunction

Organic-inorganic hybrid heterojunctions have the ability to efficiently remove trace pollutants from water due to efficient photosensitivity. In this work, an organic–inorganic hybrid S-scheme heterojunction photosensitizer (RCP-BW) was successfully fabricated by growing cross-linked β-CD/riboflavin copolymer on the surface of bismuth tungstate (Bi2WO6). The fabrication of the copolymer retains the photosensitivity of riboflavin and the confinement effect of β-CD and forms an internal electric field with Bi2WO6 to enhance the photoelectron transport ability. Photogenerated electrons are transferred and stacked from Bi2WO6 to β-CD/riboflavin copolymers, which greatly enhances the ability of organic copolymers to reduce oxygen and produce superoxide radicals. We combined electrochemistry, free radical chemistry and DFT to study the photoelectron migration mechanism and photocatalytic performance enhancement mechanism in S-scheme heterojunctions. The pseudo-first-order reaction kinetic constant (kRCP-BW = 0.081 min−1) for BPA degradation was four times that of unmodified BW (kBW = 0.020 min−1). β-CD regulates the band structure of riboflavin to match with Bi2WO6, and utilizes charged contaminants and intermediate degradation products to promote the production of reactive oxygen species through interface electron transfer and excited state transition energy transfer. This work provides theoretical support and technical means for photocatalytic oxidation technology to control endocrine disruptors.