Interfacial Electron Transfer Research Articles

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.

Enhanced methane production from anaerobic wastewater treatment by carbon nanotubes: Surface defect mediated interfacial electron transfer

Interfacial electron transfer, a crucial process in direct interspecies electron transfer (DIET) between exo-electrogenic microorganisms and conductive materials, has played a vital role in enhancing methane production in anaerobic wastewater treatment. To improve interfacial electron transfer, the construction of surface defect has been identified as an effective approach. In this study, a range of metals and non-metals were used to dope carbon nanotubes (CNTs), which were served as the conductive materials and added into anaerobic wastewater treatment systems. The effect of surface defect of CNTs on methane production were investigated. The results demonstrated that all the doped CNTs can significantly increase methane production rate in anaerobic systems. Among them, boron and iron doped CNTs (B-CNTs and Fe-CNTs) exhibited the most promising performance as non-metal and metal doped CNTs. The addition of B-CNTs and Fe-CNTs led to impressive increase of 101.6% and 149.8% in the methane production rate of the anaerobic systems. Furthermore, this study elucidated the underlying mechanisms responsible for the enhanced methane production in the anaerobic wastewater treatment with doped CNTs. The introduction of doped CNTs enriched exo-electrogenic bacteria and archaea, thereby promoting the DIET process. Additionally, the CNTs also acted as the capacitor, storing and discharging electrons, which contributed to the maintenance of a stable methane production in anaerobic wastewater treatment.

Ti3C2TX encapsulation of CTAB-functionalized polypyrrole nanospheres towards pseudocapacitive intensification in supercapacitors

The critical criteria for supercapacitor to power the increasingly prevalent portable electronic devices lies within its active material design that yields high specific capacitance without compromising rate performance. Herein, polypyrrole (PPy) was synthesized into nanospheres (PPy NS) to improve bulk ion transport kinetics. However, numerous interfaces generated by nanospherical structure induce high nanocontact resistance, resulting in low specific capacitance. Thus, PPy NS were surface-functionalized with cationic surfactant n-Cetyl-n,n,n-trimethylammonium bromide to facilitate enwrapping by highly electrically conductive Ti3C2TX nanosheets via electrostatic self-assembly, where the Ti3C2TX shells serves as effective conductive pathways. Flake sizes of Ti3C2TX nanosheets were modulated via probe ultrasonication to maximize conformability to PPy NS, minimizing tortuosity of ion diffusion pathways and establishing ubiquitous heterostructure contact. This resulted in enhanced rate performance of 74 % capacitive retention during scan rate increase from 1 to 100 mV s−1 (pure PPy NS at 58 %). Furthermore, positively charged moieties imparted by surface-functionalization of PPy NS instigate electronic coupling with negatively charged surface terminations of Ti3C2TX nanosheets, facilitating rapid interfacial electron transfer. Through simultaneous dimensional and surface charge alignment, the nanocomposite achieved specific capacitance of 619.7 F g−1 at 5 A g−1 (∼37-fold enhancement over pure PPy NS), despite incorporation of low amounts of Ti3C2TX (9 wt%). This work highlights the potential of such material integration techniques in realizing capacitive intensification beyond incremental improvements as well as boosting rate performance, with methodical employment of minimal functional additive. It serves as a framework for future studies optimizing 2D-0D material nanocomposites for supercapacitor applications.

An Electron-Coupled Co-ZrO2 Nanodot Heterojunction Electrocatalyst with Lewis Acid-Base Site Pairs Enables High Redox Reaction Kinetics of Li-S Batteries.

Using electrocatalysts is effective in solving the slow reaction kinetics of polysulfides in Li-S batteries, but designing stable electrocatalysts with an integrated adsorption-catalysis-desorption system is challenging. Here, we report a stable metal-semiconductor (Co-ZrO2) heterojunction electrocatalyst fabricated by assembling electron-coupled Co-ZrO2 nanodots into macroporous carbon nanofibers. The Co-ZrO2 contact causes interfacial electron enrichment and electron transfer from Co to ZrO2, which creates abundant Lewis-acid sites on Co that can adsorb polysulfides. Simultaneously, the enriched interfacial electrons can activate the S-S bond and boost the catalytic conversion of long-chain polysulfides, while the ZrO2 with Lewis-base sites facilitate the desorption of short-chain polysulfides from the electrocatalyst. Moreover, the nanodot heterojunctions show great chemical stability and high redox reaction kinetics of polysulfides. Li-S batteries show high discharge capacities of 954.5 mA h·g-1 at 0.5 C with a retention of 84.9% over 200 cycles, and 710.2 mA hg-1 at 1 C with a retention of 98.6% over 200 cycles. This study provides an effective strategy for developing active and durable electrocatalysts for Li-S batteries.

Enhancing interfacial electron transfer through PANI electron bridge for tailoring dynamic reconstruction and achieving high-performance water oxidation

Tailoring the dynamic reconstruction of transition metal compounds into highly active oxyhydroxides through surface electron state modification is crucial for advancing water oxidation, yet remains a formidable challenge. In this study, a unique polyaniline (PANI) electron bridge was integrated into the metal–organic frameworks (MOFs)/layer double hydroxides (LDHs) heterojunction to expedite electron transfer from MOFs to LDHs, facilitating electron accumulation at the metal sites within MOF and electron-deficient LDHs. This configuration promotes the surface dynamic reconstruction of LDHs into highly active oxyhydroxides while safeguarding the MOF from corrosion in harsh environments over extended periods. The optimized electronic structure modification of both MOFs and LDHs enhances reaction kinetics. The superior MIL-88B(Fe)@PANI@NiCo LDH catalyst achieved 10 mA∙cm−2 at an overpotential of 202 mV and demonstrated stable operation for 120 h at this current density. This research introduces an innovative approach for guiding electron transfer and dynamic catalyst reconstruction by constructing a PANI electron bridge, potentially paving the way for more efficient catalytic systems.

Restrained interfacial resistance Co5.47N@C derived from metal-organic frameworks for advanced Li–CO2 batteries cathodes

Lithium–carbon dioxide (Li–CO2) batteries are novel high energy density energy storage devices that can simultaneously enrich and convert CO2, but their widespread implementation is hindered by the continuous accumulation of lithium carbonate at the cathode. Herein, we developed non-precious metal cobalt-based nitride matrix composite Co[Formula: see text]N@C based on metal-organic frameworks precursor for the catalytic cathode of advanced Li–CO2 batteries. The highly stable Co[Formula: see text]N achieves favorable adsorption and catalysis of CO2 molecules by virtue of the excellent electronic structure on the surface, while the nanoscale high dispersion also effectively promotes interfacial electron transfer. As expected, the assembled Li–CO2 battery exhibits excellent electrochemical performance in the discharge capacity of 10,000 mAh g[Formula: see text] and a cycling capability of about 400 h. Further density functional theory (DFT) calculations explored the relationship between electronic structure and electrochemical activity. This work promotes the development of catalytic materials for Li–CO2 batteries cathode.

Polyacrylonitrile-based 3D N-rich activated porous carbon synergized with Co-doped MoS2 for promoted electrocatalytic hydrogen evolution

MoS2 is a promising electrocatalyst for the hydrogen evolution reaction (HER), but it is limited by its own agglomeration, low conductivity, and surface inertness. In this study, we report a well-organized 3D hybrid structure of N-rich active porous carbon (CN) synergized with Co-doped molybdenum disulfide (Co-MoS2@CN) for promoted electrocatalytic hydrogen evolution. MoS2 nanosheets were grown vertically on CN and the pore structure was improved, which exposed abundant edge active sites. The N-rich graphite structure and abundant pore structure of CN enhanced the electron transfer ability and stability of the 3D hybrid structure. Meanwhile, doping of Co atoms optimized the catalytic activity of the in-plane sulfur sites and induced a partial transition from 2H-MoS2 to 1 T-MoS2. The resulting Co-MoS2@CN 3D hybrid structure exhibited excellent HER electrocatalytic performance, had a current density of 10 mA cm−2 in a 0.5 M H2SO4 aqueous solution by an overpotential of 137 mV, and showed excellent stability in a 24 h HER test. DFT calculations confirmed that the heterogeneous interface constructed by CN and Co-MoS2 effectively optimized Gibbs free energy (ΔGH*) of the MoS2 hydrogen adsorption site and enhanced the interfacial electron transfer capacity, which ensured rapid HER kinetics during the electrocatalytic process.

Modulating *OOH Adsorption on RuO2 for Efficient and Durable Acidic Water Oxidation Electrocatalysis.

Acidic water electrolysis is of considerable interest due to its higher current density operation and energy conversion efficiency, but its real industrial application is highly limited by the shortage of efficient, stable, and cost-effective acidic oxygen evolution reaction (OER) electrocatalysts. Here,an electrocatalyst consisting of Ni-implanted RuO2 supported is reported on α-MnO2 (MnO2/RuO2-Ni) that shows high activity and remarkable durability in acidic OER. Precisely, the MnO2/RuO2-Ni catalyst shows an overpotential of 198mV at a current density of 10mA cm-2 and can operate continuously and stably for 400h (j = 10mA cm-2) without any obvious attenuation of activity, making it one of the best-performing acid-stable OER catalysts. Experimental results, in conjunction with density functional theory calculations, demonstrate that the interface electron transfer effect from RuO2 to MnO2, further enhanced by Ni incorporation, effectively modulates the adsorption of OOH* and significantly reduces the overpotential, thereby enhancing catalytic activity and durability.

Enhancing interfacial electron transfer and photoelectrochemical kinetics for efficient water-treatment strategy through N-doped carbon dots modified PhC2Cu

To improve the water environment quality, the development of an effective photocatalyst for pollutant removal was considered a promising strategy. The aim of the development of a novel photocatalyst PNC is pursued by modifying copper-phenylacetylide (PhC2Cu) with nitrogen-doped carbon quantum dots (N-CDs). Leading to a remarkable improvement in its light absorption capability, electron transfer efficiency and photoelectrochemical properties. Importantly, PNC possesses the characteristic of straightforward synthesis and demonstrates remarkable performance in the photodegradation of 99.87% sulfamethoxazole (SMX) within just 15 min, with a 3.95-fold increase in the photocatalytic rate. Analysis of the active substances revealed that 1O2, O2·‐, and h+ are the generated active species by PNC. Active sites and degradation pathways of SMX were explored through density functional theory (DFT) calculations and intermediate analysis. Key evidence regarding the direction of electron transfer within the system was obtained through in-situ irradiated X-ray (ISI-XPS) techniques. This study deepened our understanding of the electron transfer characteristics of phenylacetylene copper and provided new insights for the modification of photocatalysts.

Engineering FeOOH/Fe2O3@Carbon Interfaces With Biomass-Derived Carbon Nanodot/Iron Colloids for Efficient Redox-Modulated Dopamine Voltammetric Detection.

The Fe2+/Fe3+ redox couple is effective for voltammetric detection of trace dopamine (DA). However, achieving adequate concentrations with high electroactive surface area (ECSA), DA affinity, and fast interfacial charge transfer is challenging. Consequently, most reported Fe-based sensors have a high nanomolar range detection limit (LOD). Herein, we address these limitations by manipulating the phase and morphology of FeOOH/Fe2O3 heterojunctions anchored on sp2-carbon. FeOOH/Fe2O3 is synthesized by variable temperature aging of unique Fe5H9O15/Fe2O3@sp2-carbon colloidal nanoparticles, which form via chelation between biomass-derived carbon nanodots (CNDs) and Fe2+ ions. At 27 °C and 120 °C, Fe5H9O15/Fe2O3@sp2-carbon transforms into β-FeOOH/Fe2O3 nanoparticles and α-FeOOH/Fe2O3 nanosheet, respectively. The β-FeOOH/Fe2O3 interface exhibits higher eg orbital electron occupancy than α-FeOOH/Fe2O3, thereby facilitating oxygen adsorption and the generation of Fe2+/Fe3+ sites near the polarization potential of DA. This facilitates interfacial electron transfer between Fe3+ and DA. Moreover, its nanoparticle morphology enhances ECSA and DA adsorption compared to α-FeOOH/Fe2O3 nanosheets. With a LOD of ~3.11 nM, β-FeOOH/Fe2O3 surpasses the lower threshold in humans (~10 nM) and matches noble-metal sensors. Furthermore, it exhibits selective detection of DA over 10 biochemicals in urine. Therefore, the β-FeOOH/Fe2O3@sp2-C platform holds promise as a low-cost, easy-to-synthesize, and practical voltammetric DA monitor.

Heterogeneous interface engineering of CoPSe and FePSe3 on open frameworks for boosting highly efficient overall water splitting

Enhancing intrinsic activity of nanostructured heterogeneous catalysts is an effective strategy for improving electrocatalytic performance for hydrogen/oxygen evolution reactions (HER/OER), but it remains challenging. Here, phosphorus (P) and selenium (Se) atoms are incorporated into an open Co-Fe-based Prussian blue analogues to form a heterostructure consisting of CoPSe and FePSe3 via a one-step pyrolysis strategy. The CoPSe/FePSe3 heterojunction greatly reduces the overpotential for HER (91 mV) or OER (172 mV), which is close to that of Pt/C or much better than that of RuO2, respectively. Co-doping of P and Se non-metallic atoms promotes the reaction kinetics and the exposure of active sites in the framework structure with a large specific surface area. The interactions between CoPSe and FePSe3 can eagerly promote the interfacial electron transfer to enhance HER/OER activities. The carbon skeleton can effectively avoid the fast corrosion/aggregation of the embedded CoPSe/FePSe3 heterojunctions, thereby enhancing the catalytic/structural stability for HER/OER. Importantly, for overall water splitting, the electrolyzer with CoPSe/FePSe3 catalyst only requires an overpotential of 0.35 V to achieve a long-term stability (36 h) at 10 mA cm−2, with Faradaic efficiencies near 100 %. This work sheds a new light on promotion of intrinsic activity of heterostructured catalysts for water splitting.

Unlocking Single Particle Anisotropy in Real‐Time for Photoelectrochemistry Processes at the Nanoscale

AbstractThe key to rationally and rapidly designing high‐performance materials is the monitoring and comprehension of dynamic processes within individual particles in real‐time, particularly to gain insight into the anisotropy of nanoparticles. The intrinsic property of nanoparticles typically varies from one crystal facet to the next under realistic working conditions. Here, we introduce the operando collision electrochemistry to resolve the single silver nanoprisms (Ag NPs) anisotropy in photoelectrochemistry. We directly identify the effect of anisotropy on the plasmonic‐assisted electrochemistry at the single NP/electrolyte interface. The statistical collision frequency shows that heterogeneous diffusion coefficients among crystal facets facilitate Ag NPs to undergo direction‐dependent mass transfer toward the gold ultramicroelectrode. Subsequently, the current amplitudes of transient events indicate that the anisotropy enables variations in dynamic interfacial electron transfer behaviors during photothermal processes. The results presented here demonstrate that the measurement precision of collision electrochemistry can be extended to the sub‐nanoparticle level, highlighting the potential for high‐throughput material screening with comprehensive kinetics information at the nanoscale.

Unlocking Single Particle Anisotropy in Real-Time for Photoelectrochemistry Processes at the Nanoscale.

The key to rationally and rapidly designing high-performance materials is the monitoring and comprehension of dynamic processes within individual particles in real-time, particularly to gain insight into the anisotropy of nanoparticles. The intrinsic property of nanoparticles typically varies from one crystal facet to the next under realistic working conditions. Here, we introduce the operando collision electrochemistry to resolve the single silver nanoprisms (Ag NPs) anisotropy in photoelectrochemistry. We directly identify the effect of anisotropy on the plasmonic-assisted electrochemistry at the single NP/electrolyte interface. The statistical collision frequency shows that heterogeneous diffusion coefficients among crystal facets facilitate Ag NPs to undergo direction-dependent mass transfer toward the gold ultramicroelectrode. Subsequently, the current amplitudes of transient events indicate that the anisotropy enables variations in dynamic interfacial electron transfer behaviors during photothermal processes. The results presented here demonstrate that the measurement precision of collision electrochemistry can be extended to the sub-nanoparticle level, highlighting the potential for high-throughput material screening with comprehensive kinetics information at the nanoscale.

Bimetallic Ag/Fe-MOG derived flake-like Ag2O/Fe2O3 p-n heterojunction for efficient photodegradation organic pollutants within a wide pH range

In this paper, we reported a facile and clean strategy to prepare the flake-like Ag2O/Fe2O3 bimetallic p-n heterojunction composites for photodegradation organic pollutants. The surface morphology, crystal structure, chemical composition and optical properties of Ag2O/Fe2O3 were characterized by SEM, high-resolution TEM images with EDX spectra, XRD, XPS, FT-IR and UV–vis DRS spectra respectively. The formation of Ag2O/Fe2O3 p-n heterojunction facilitated the interfacial transfer of electrons as well as the separation of charge carries. Hence, the as-synthesized Ag2O/Fe2O3-3 composites exhibited ultra-high photocatalytic activity. Under the experimental conditions of catalyst dosage of 0.4 mg mL−1 and irradiation time of 60 min, the degradation conversion rate of rhodamine B reached 96.1 %, which was 5.0 and 2.8 times of pure phase Ag2O and Fe2O3, respectively. Meanwhile, the degradation performance of Ag2O/Fe2O3-3 was not limited by pH, and it can achieve high degradation efficiency under 3–11. In addition, Ag2O/Fe2O3-3 also showed superb degradation ability for other common anionic dyes, cationic dyes and antibiotics. XPS and FT-IR spectra showed that Ag2O/Fe2O3-3 retained a carbon skeleton that facilitated electron transport and light absorption conversion. And the analyses of quenching experiment and EPR demonstrated •O2−, •OH and h+ were crucial reactive oxidant species contributing to the rapid organic pollutant degradation. This work provides new insights into obtaining p-n photocatalysts heterojunction with excellent catalytic activity for removing organic pollutants from wastewater.

Influence of tartaric acid on the electron transfer between oxyanions and lepidocrocite

Iron oxide minerals control the environmental behavior of trace elements. However, the potential effects of electron transfer directions by iron oxides between organic acids and trace elements remain unclear. This study investigates the redox capacity of tartaric acid (TA) with chromate (Cr(Ⅵ)) or arsenate (As(V)) on lepidocrocite (Lep) from the perspective of electron transfer. The results demonstrated the configurations of TA (bidentate binuclear (BB)), As(V) (BB), and Cr(Ⅵ) (BB and protonated monodentate binuclear (HMB)) on Lep. Frontier molecular orbital calculations and X-ray photoelectron spectroscopy (XPS) binding energy shifts further indicated different electron transfer directions between TA and the oxyanions on Lep. The iron of Lep might act as electron acceptors when TA is adsorbed, whereas the iron and oxygen of Lep act as electron donors when As(V) is adsorbed. The iron of Lep might accept electrons from its oxygen and subsequently transfer these electrons to Cr(Ⅵ). Macroscopic validation experiments showed the reduction of Cr(VI), whereas no reduction of As(V). The XPS analysis showed a peak shift, with the possible formation of As–Fe–TA ternary complexes and electron transfer on Lep. These findings indicate that mineral interfacial electron transfer considerably influences the transport and transformation of oxyanions.

Boosting Interfacial Electron Transfer and CO2 Enrichment on ZIF-8/ZnTe for Selective Photoelectrochemical Reduction of CO2 to CO.

Artificial photosynthesis is an effective way of converting CO2 into fuel and high value-added chemicals. However, the sluggish interfacial electron transfer and adsorption of CO2 at the catalyst surface strongly hamper the activity and selectivity of CO2 reduction. Here, we report a photocathode attaching zeolitic imidazolate framework-8 (ZIF-8) onto a ZnTe surface to mimic an aquatic leaf featuring stoma and chlorophyll for efficient photoelectrochemical conversion of CO2 into CO. ZIF-8 possessing high CO2 adsorption capacity and diffusivity has been selected to enrich CO2 into nanocages and provide a large number of catalytic active sites. ZnTe with high light-absorption capacity serves as a light-absorbing layer. CO2 molecules are collected in large nanocages of ZIF-8 and delivered to the ZnTe surface. As evidenced by scanning electrochemical microscopy, the interface can effectively boost interfacial electron transfer kinetics. The ZIF-8/ZnTe photocathode with unsaturated Zn-Nx sites exhibits a high Faradaic efficiency for CO production of 92.9% and a large photocurrent of 6.67 mA·cm-2 at -2.48 V (vs Fc/Fc+) in a nonaqueous electrolyte at AM 1.5G solar irradiation (100 mW·cm-2).

Variation of Chemical Microenvironment of Pores in Hydrazone-Linked Covalent Organic Frameworks for Photosynthesis of H2O2.

Photocatalytic synthesis of H2O2 is an advantageous and ecologically sustainable alternative to the conventional anthraquinone process. However, achieving high conversion efficiency without sacrificial agents remains a challenge. In this study, two covalent organic frameworks (COF-O and COF-C) were prepared with identical skeletal structures but with their pore walls anchored to different alkyl chains. They were used to investigate the effect of the chemical microenvironment of pores on photocatalytic H2O2 production. Experimental results reveal a change of hydrophilicity in COF-O, leading to suppressed charge recombination, diminished charge transfer resistance, and accelerated interfacial electron transfer. An apparent quantum yield as high as 10.3% (λ = 420 nm) can be achieved with H2O and O2 through oxygen reduction reaction. This is among the highest ever reported for polymer photocatalysts. This study may provide a novel avenue for optimizing photocatalytic activity and selectivity in H2O2 generation.

Magnetic porous microspheres altering interfacial thermodynamics of sewage sludge to drive metabolic cooperation for efficient methanogenesis

Controllable and recyclable magnetic porous microspheres (MPMs) have been proposed as a means for enhancing the anaerobic digestion (AD) of sludge, as they do not require continuous replenishment and can serve as carriers for anaerobes. However, the effects of MPMs on the interfacial thermodynamics of sludge and the biological responses triggered by abiotic effects in AD systems remain to be clarified. Herein, the underlying mechanisms by which MPMs alter the solid–liquid interface of sludge to drive methanogenesis were investigated. A significant increase in the contents of 13C and 2H (D) in methane molecules was observed in the presence of MPMs, suggesting that MPMs might enhance the CO2-reduction methanogenesis and participation of water in methane generation. Experimental results demonstrated that the addition of MPMs did not promote the anaerobic bioconversion of soluble organics for methanogenesis, suggesting that the enhanced methanogenesis and water participation were not achieved through promotion of the bioconversion of original liquid-state organics in sludge. Analyses of the capillary force, surface adhesion force, and interfacial proton-coupled electron transfer (PCET) of MPMs revealed that MPMs can enhance mass transfer, effective contact, and electron–proton transfer with sludge. These outcomes were confirmed by the statistical analyses of variations in the interfacial thermodynamics and PCET of sludge with and without MPMs during AD. It was thus proposed that the MPMs enhanced the PCET of sludge and PCET-driven release of protons from water by promoting the interfacial Lewis acid–base interactions of sludge, thereby resulting in the enrichment of free and attached methanogenic consortia and the high energy-conserving metabolic cooperation. This proposition was further confirmed by identifying the predominant syntrophic partners, suggesting that PCET-based efficient methanogenesis was attributable to the enrichment of genomes harbouring CO2-reducing pathway and genes encoding water-mediated proton transfer. These findings offer new insights into how substrate properties can be altered by exogenous materials to enable highly efficient methanogenesis.

An innovative Zn3In2S6/ZnIn2S4 homojunction photocatalyst with enhanced interfacial charge transfer for the highly efficient degradation of tetracycline under visible radiation

The interfacial charge transfer ability is a decisive factor influencing the photocatalytic performance of composite photocatalysts. Compared with heterojunctions that combine two or more semiconductors with different properties, homojunctions that combine two semiconductors with similar properties can accelerate the interfacial charge shift and achieve higher photocatalyticability. In this study, a Zn3In2S6/ZnIn2S4 homojunction photocatalyst (ZIS-5) with a Zn3In2S6 to ZnIn2S4 molar ratio of 5:1 was synthesized by selecting Zn3In2S6 nano-microspheres as the substrate material and growing ZnIn2S4 flocs on the nano-microspheres. The photocatalytic performance of the ZIS-5 homojunction was assessed by using tetracycline (TC) as a typical pollutant. The photocatalytic performance and mineralization rate of the ZIS-5 homojunction were significantly improved compared with those of Zn3In2S6 and ZnIn2S4, and its photocatalytic performance was increased by 10.2% and 20.9%, compared with Zn3In2S6 and ZnIn2S4, respectively, while the mineralization rate was enhanced by 22.78% and 43.28%, respectively. The results of the comparison experiment revealed that the interfacial electron transfer ability of the ZIS-5 homojunction is 1.6 times that of the g-C3N4/ZnIn2S4-5 heterojunction. The density functional theory (DFT) computation and Mott–Schottky plots verified the formation of an internal electric field. The toxicity analysis showed that the ZIS-5 homojunction system effectively reduced the toxicity of TC. This work supplies a valuable route for inventing catalysts with efficient photocatalytic performances.

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.