Fast Electron Transfer Research Articles

New Insights into Selective Singlet Oxygen Production via the Typical Electroactivation of Oxygen for Water Decontamination.

Selective production of singlet oxygen (1O2) as an electrophilic oxidant is crucial for the precise control of chemical targets in environmental fields. Herein, we proposed a strategy to construct a redox interface on electrodes, which can in situ produce inorganic metal hydroperoxides with appropriate oxidative ability during oxygen activation. Benefiting from atomic Cu sites (CuN4) in a copper-carbon aerogel electrode, almost complete production of 1O2 was achieved, thereby refraining the competitive formation of other reactive oxygen species. The fast electron transfer rate between CuN4 and electrogenerated H2O2 promoted the in situ formation of copper hydroperoxide (N4-Cu-OOH), thereby selectively and efficiently oxidizing intermediate O2•- to 1O2. The optimized production of 1O2 was up to 2583 μmol L-1 without additional chemical reagents. We further considered the high production of 1O2 for efficiently removing electron-rich organic pollutants from a complex water matrix. Fast kinetics was achieved and considered for removing various pollutants with electron-donating substituents in a nonradical oxidation pathway. The BPA degradation efficiency is less susceptible to the coexisting natural organic matter (NOM) and inorganic ions. Specifically, the kinetic constant for BPA removal is 34 times higher than that for a nanoparticle of a copper-carbon electrode while producing a hydroxyl radical. Our findings highlight the innovative interfacial surface engineering of an electrocatalytic O2 activation system to selectively generate 1O2 for future potential applications.

Highly sensitive voltammetric sensor comprising CuSn(OH)6–multi-walled carbon nanotubes–β-cyclodextrin composites and poly(L-arginine) for indole-3-lactic acid analyses in alcohol use disorder serum samples

A highly sensitive voltammetric sensing platform configured via the drop-casting of composites of CuSn(OH)6–multi-walled carbon nanotubes–β-cyclodextrin (CuSn(OH)6–MWCNT–βCD) on an arginine-electropolymerized screen-printed carbon electrode (CuSn(OH)6–MWCNT–βCD/p-Arg/SPCE) was demonstrated to determine the concentrations of indole-3-lactic acid (ILA) in buffer and serum solutions. Prior to the analysis, the successful assembly of the composites and polymer layers was confirmed using field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The changes in the current due to the direct oxidation of ILA on the modified electrode were used to quantify the ILA. A dynamic range of 0.05–20 μM with a limit of detection of 9 nM for ILA under optimal conditions was achieved primarily with the combined use of CuSn(OH)6, MWCNT, and βCD, resulting in a large electrochemical active surface area (0.185 cm2), low charge transfer resistance (∼2 Ω), and fast electron transfer. Furthermore, the sensing performance, including selectivity, sensitivity, reproducibility, repeatability, and stability, for ILA detection was evaluated. Finally, the ILA concentrations in the pooled clinical serum samples of healthy control and alcohol use disorder patients were measured using our method, the results of which exhibited a notable resemblance to those obtained using liquid chromatography with tandem mass spectrometry.

In-situ engineering of 3D porous Co nanoparticles incorporated in B/N Co-doped carbon nanotube/nanofiber networks as integrated cathode materials for Zn-air batteries

Rational design and construction of low-cost and highly efficient bifunctional catalysts toward oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is crucial for the commercialization of the rechargeable Zn-air batteries (ZABs). Herein, a 3D self-standing bifunctional catalytic electrode has been successfully achieved by in-situ confinement of Co nanoparticles into B/N co-doped carbon nanotube/nanofiber well-integrated networks (Co-B/N-CNTs@CFs). The purpose of designing such a 3D network structure is to optimize the electronic structure of the active sites for high electrocatalytic activity, ensure continuous and fast electron and charge transfer for high utilization of active sites, and avoid the abscission and aggregation of nanocatalysts for high electrocatalytic stability, which is confirmed by a series of experimental, characterization, and theoretical studies. As a result, the Co-B/N-CNTs@CFs as integrated cathode materials deliver efficient and stable OER/ORR performance with a ΔE of 0.59 V, largely outperforming the benchmark Pt/C-RuO2 electrode (0.71 V), and hence leading to appealing applications in both the assembled aqueous and flexible solid-state ZABs. This study forges a new path for the production of integrated cathode while enhancing their superiority, allowing for the construction of energy storage devices.

Graphene quantum dots-polyfluorene hybrid nanobiosensor for mitomycin C-DNA interaction sensing

A novel graphene quantum dots (GQD) / polyfluorene (PF) nanocomposite was deposited on the disposable pencil tip graphite electrode (PGE) and proven to be an efficient nanosensor for analysis of the electrochemical interaction between the antitumor compoundmitomycinC(MC) with double stranded DNA (ds-DNA). This modified electrode (GQD@PF-PGE) was prepared in four steps: hydrothermal, chemical oxidation, ultrasonication and electro-oxidation processes. GQD, PF, GQD@PF and GQD@PF-PGE have been characterized by different analytical techniques such as SEM, TEM, XRD, FTIR, UV–Vis, EIS. Compared to bare PGE, GQD@PF modified PGE performed approximately 56 times more sensitive analysis when evaluating the guanine oxidation signals measured by DPV. CV and EIS measurements also showed that GQD@PF-PGE possesses a fast electron transfer as compared to bare electrode and exhibit a remarkable electrocatalytic activity towards both guanine and MC electrooxidation. Comprehensive optimization studies have also been carried out for the developed new nanobiosensor.

Rapid peroxymonosulfate activation by self-assembly of layered fluorine-free MXene with nanofibrous Co3O4: Antibiotic degradation and electron transfer mechanism

Herein, nanofibrous Co3O4 was self-assembled with lamellar fluorine-free MXene (Ff-Ti3C2Tx) to prepare a nanofibrous layered structure of Ff-Ti3C2Tx-Co3O4. Benefiting from the unique structure, Ff-Ti3C2Tx-Co3O4 exhibited excellent catalytic activity for degradation (nearly 100%) in the pH range of 4–10 and was resistant to ionic interference. The Ff-Ti3C2Tx-Co3O4 membranes were prepared by vacuum filtration, permeated 220 mL of sulfamethoxazole (SMX) in the municipal wastewater influent matrix and maintained removal efficiency above 95%. Furthermore, PMS decomposition was linearly correlated with SMX degradation and each millimolar of PMS oxidized 0.425 mM of SMX. Meanwhile, electrons were rapidly transferred from Ff-Ti3C2Tx-Co3O4 to PMS to consume HCO5− and produce metastable active species (Ff-Ti3C2Tx-Co3O4-PMS*). The mechanism of rapid SMX degradation involved fast electron transfer in Ti2+/Ti3+⇋Ti4+ and Co2+⇋Co3+ redox cycles with PMS. Furthermore, 1O2 was generated via PMS→·O2−→1O2. This work provides new inspiration into the mechanisms of antibiotic degradation and electron transfer based on PMS activation.

In-situ fabrication of vertical heterogeneous nickel diselenide-molybdenum diselenide architectures as bifunctional overall water-splitting electrocatalyst

Despite the rapid advances in electrocatalysts based on two-dimensional (2D) transition metal dichalcogenides (TMDs) materials, they are subject to serious aggregation, poor conductivity and the presence of inactive basal planes. Herein, we have successfully demonstrated the in-situ construction of NiSe2–MoSe2 heterostructure arrays on carbon cloth (NiSe2–MoSe2/CC) by a facile two-step hydrothermal process. The presence of the synergistic effect in the heterostructures effectively optimizes the poor conductivity and hydrophilicity, and thus enables fast electron transfer, leading to enhanced electrochemical reaction. Furthermore, density functional theory calculations reveal that the electrons redistribution at the heterojunction interface and the reduced Gibbs free energy of hydrogen adsorption for hydrogen evolution reaction (HER)/the Gibbs free energy change value of rate-determining step for oxygen evolution reaction (OER), thus enhancing the HER/OER catalytic activity. Importantly, the device displays a good performance with a low overpotential of 98 and 310 mV for HER and OER, respectively, and a low cell voltage of 1.59 V for its corresponding electrolyzer (10 mA cm−2). This work presents the high-performance water splitting of bifunctional electrocatalysts based on 2D TMDs materials and offers a novel design concept of interface engineering.

Fabrication of PANI supported magnesium/cobalt spinel ternary oxide as an efficient oxygen evolution reaction and removal of organic pollutant

The advancement of potent, highly efficient and reasonably priced catalysts is necessary for the production of hydrogen from a renewable source and removal of organic contaminants from waste water. In this study, we demonstrated the dynamic proportion capability of the hydrothermally condensed polymorphic electrocatalyst MgCo2O4/PANI nanocomposite. The composite material has higher surface area of 264 m2 g-1 and electrochemical active surface area of 299.5 cm2. The MgCo2O4/PANI nanocomposite exhibits 201 mV of lower overpotential to attain at 10 mA cm-2 of current density and 66 mV dec-1 of reduced Tafel value. The long-term viability for 50 h is demonstrated using MgCo2O4/PANI at 10 mA cm-2 for O2 production. The findings of this study demonstrated that MgCo2O4/PANI nanocomposite is an affordable, non-precious material, which can be utilized to generate H2 on a large scale. On the other hand, the resultant material was then applied for the Congo Red (CR) dye photodegradation irradiated with visible light with degradation efficiency of 98%. The comparison of nanostructured MgCo2O4/PANI demonstrates that the electrochemical performance for water oxidation processes as well as degradation process is significantly higher than the pure form. The exceptional catalytic performance of MgCo2O4/PANI nanocomposite is due to the large quantity of active sites, some immense oxygen vacancies, and a fast electron transfer rate, with a steady oxygen generating stability of 1500 cycles confirm the endurance of MgCo2O4/PANI nanoarrays, which is beneficial for future industrial application.

Electronic modulation and synergistic effect on Fe-doped NiSe@NiS composites to improve oxygen evolution performance

In this paper, Fe-doped nickel selenide and nickel sulfide composites was in-situ grown on nickel foam (NF) to prepare Fe-NiSe@NiS/NF by solvothermal method. Benefit from the optimized electron structure by Fe doping, the synergistic effect of NiSe@NiS and faster electron transfer, Fe-NiSe@NiS/NF exhibited excellent OER activity with the overpotential of 330 mV at 150 mA/cm2 in 1 mol/L KOH solution. The voltage barely changed after 40 h of test.

Evaluation of templated N/P co-doped hierarchical mesoporous biocarbon/2D-molybdenum disulfide/polypyrrole composite as a supercapacitor electrode for U(VI) electrosorption

In this work, a templated N/P co-doped hierarchical porous biocarbon was prepared through the carbonization of sugar at high temperature (700 °C). Then, this porous biocarbon was in-situ functionalized with molybdenum disulfide nanosheets through a hydrothermal treatment reaction to get the composite, SC/MoS2. Later, SC/MoS2 on a nickel foam substrate was electrodeposited with different concentrations of polypyrrole, a conducting polymer, at −0.9 V. The prepared composite electrodes (SC/MoS2/PPy) were characterized thoroughly using FTIR, XRD, BET, and SEM. The orderly developed mesoporosity and N, P doping inside the porous carbon network was found to be highly conducive for the U(VI) electrosorption accomplished through capacitive deionization (CDI). The composites had remarkable specific capacitance (95.4 F/g), a large specific surface area (174.4–273.6 m2/g), improved mesopore volume (0.58 cm3/g) and excellent Vm/Vt ratio (0.80). SC/MoS2/PPy-2, among other composites, revealed fast electrosorption kinetics and excellent selectivity with a maximum sorption capacity of 300.66 ± 8.02 mg/g at −0.9 V. The SC/MoS2/PPy-2 retained relatively small charge transfer resistance Rct (1.22 Ω cm2), minute electrolytic resistance Rs (0.77 cm2), and a large double layer constant phase element qdl (0.0369 S sn/cm2) which makes it suitable for U(VI) ion diffusion and fast electron transfer during CDI performance. The composite electrode materials offer novel and potent desalination applications, specifically in uranium extraction from aqueous media.

Computational investigation of dyes-sensitized solar cells containing various π-bridges achieving high photovoltaic performance with triazatruxene-based dyes

In this work, three organic triazatruxene-based dyes, containing cyanoacrylic acid as acceptor and different five-membered rings in the π-bridge, such as 5,5-Dimethylcyclopentadiene for TAT-C, furan for TAT-O and 1,1-dimethyl-1H-silole for TAT-Si, were theoretically investigated by density functional theory (DFT) and time-dependent (TD-DFT) for application in dye-sensitized solar cells (DSSCs). Geometry, electrical structure, intramolecular charge transfer (ICT), reorganization energy, light-harvesting efficiency (LHE), and other microscopic factors were examined to determine how the π-bridges affected short-circuit current (JSC) and open circuit voltage (VOC). Our theoretical findings show that dye TAT-C exhibits remarkably better light-harvesting ability in the near-infrared region, with a broader LHE curve and a greater JSC. In parallel, all three dyes have a fast interfacial electron transfer (IET) rate. Furthermore, based on the overall evaluation model, we estimate the power conversion efficiency (PCE) for the TAT-C dye is 27.23 % (JSC = 37.30 mA.cm-2, VOC=0.838 V), followed by the dye TAT-O (PCE = 25.80 %, JSC=34.19 mA.cm-2, VOC= 0.868 V), and finally, the TAT-Si (PCE = 24.12 %, JSC=30.80 mA.cm-2, VOC= 0.898 V).Consequently, the principal objective of this investigation is to contribute a theoretical framework for creating and making novel organic dyes for promising DSSC applications.

Layer interfacing strategy to derive free standing CoFe@PANI bifunctional electrocatalyst towards oxygen evolution reaction and methanol oxidation reaction

Developing inexpensive, highly electrochemically active, and stable catalysts towards electrochemical studies remains challenge for researchers. In this regard, binder-free CoFe@PANI composite electrocatalyst is deposited on nickel foam (NF) substrate via successive electrodeposition of polyaniline (PANI) and CoFe-LDH at Room temperature (RT). As deposited binder-free CoFe@PANI electrocatalyst displays high electrocatalytic activity towards oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) in alkaline media. In CoFe@PANI structure, interfacing of high-electron conducting PANI establishes strong interconnection with CoFe-LDH by tuning electronic structures, which accelerates the electrochemical performance towards OER and MOR. For OER, CoFe@PANI requires low overpotential (η10) of 237 mV to reach current density (Id) of 10 mA cm−2 and displays low Tafel slope value of 46 mV dec−1 in 1 M KOH solution. Also, it displayed specific Id of 120 mA cm−2, when it was tested for MOR in 1 M KOH with 0.5 M methanol solution. The superior electrocatalytic activity of CoFe@PANI is mainly ascribed to high electrochemical active surface area (ECSA), abundant active sites and fast electron transfer between electrocatalyst and electrode surface. Of note, the current work may open new era for design and development of non-precious highly active and stable hybrid electrocatalysts at RT for various applications.

Structure-phase transformation of bismuth oxide to BiOCl/Bi24O31Cl10 shoulder-by-shoulder heterojunctions for efficient photocatalytic removal of antibiotic

Developing heterojunction photocatalyst with well-matched interfaces and multiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal, but still remains a great challenge. In present work, a new strategy of chloride anion intercalation in Bi2O3 via one-pot hydrothermal process is proposed. The as-prepared Ta-BiOCl/Bi24O31Cl10 (TBB) heterojunctions are featured with Ta-Bi24O31Cl10 and Ta-BiOCl lined shoulder-by-shouleder via semi-coherent interfaces. In this TBB heterojunctions, the well-matched semi-coherent interfaces and shoulder-by-shoulder structures provide fast electron transfer and multiple transfer paths, respectively, leading to enhanced visible light response and improved photogenerated charge separation. Meanwhile, a type-II heterojunction for photocharge separation has been obtained, in which photogenerated electrons are drove from the CB (conduction band) of Ta-Bi24O31Cl10 to the both of bilateral empty CB of Ta-BiOCl and gathered on the CB of Ta-BiOCl, while the photogenerated holes are left on the VB (valence band) of Ta-Bi24O31Cl10, effectively hindering the recombination of photogenerated electron-hole pairs. Furthermore, the separated electrons can effectively activate dissolved oxygen for the generation of reactive oxygen species (·O2−). Such TBB heterojunctions exhibit remarkably superior photocatalytic degradation activity for tetracycline hydrochloride (TCH) solution to Bi2O3, Ta-BiOCl and Ta-Bi24O31Cl10. This work not only proposes a Ta-BiOCl/Bi24O31Cl10 shoulder-by-shoulder micro-ribbon architectures with semi-coherent interfaces and successive type-II heterojunction for highly efficient photocatalytic activity, but offers a new insight into the design of highly efficient heterojunction through phase-structure synergistic transformation strategy.

Vanadium nitride decorated carbon cloth anode promotes aniline degradation and electricity generation of MFCs by efficiently enriching electroactive bacteria and promoting extracellular electron transfer

To increase the colonization of electroactive bacteria and accelerate the rate of extracellular electron transfer, a simple coated anode of microbial fuel cell was designed. Here, we took advantage of vanadium nitride (VN) particles to modify the carbon cloth (VN@CC). Compared with bare carbon cloth, the designed VN@CC bioanodes exhibited a larger electrochemically active area, better biocompatibility, and smaller charge transfer impedance. The MFC with VN@CC bioanodes achieved the maximum power density of 3.89 W m−2 and chemical oxygen demand removal rate of 84% when 1000 mg L−1 aniline was degraded, which were about 1.88 and 2.8 times that of CC. The morphology of biofilm and 16s rRNA gene sequence analysis proved that the VN@CC bioanodes facilitated the enrichment of electroactive bacteria (99.02%) and increased the ratio of fast electron transfer in the extracellular electron transfer, thus enhancing the MFC performance of aniline degradation and power output. This work disclosed that it was feasible to increase the overall performance of MFC by enhancing the EET efficiency and presented valuable insights for future work.

Interfacial engineering of nickel selenide with CeO2 on N-doped carbon nanosheets for efficient methanol and urea electro-oxidation

The design of low cost, high efficiency electrocatalysts for methanol oxidation reactions (MOR) and urea oxidation reactions (UOR) is a pressing need to address the energy crisis and water pollution. In the present work, we developed Cerium dioxide (CeO2) and nickel selenide (Ni0.85Se) nanoparticles integrated into three-dimensional N-doped carbon nanosheets to be used as efficient and stable bifunctional electrocatalysts for MOR and UOR. By optimizing the selenization temperature, the CeO2-modified Ni0.85Se obtained at selenization temperature of 550 °C (CeO2-Ni0.85Se-550-NC) has the best MOR and UOR electrochemical performance. The CeO2-Ni0.85Se-550-NC potential only requires 1.309 V (MOR) and 1.294 V (UOR) to reach 10 mA cm−2, respectively. The DFT study reveals that CeO2-Ni0.85Se-550-NC has the best reaction path with the synergistic effect between CeO2 and Ni0.85Se. The outstanding catalytic performance of CeO2-Ni0.85Se-550-NC may be due to the cointeraction between CeO2 and Ni0.85Se, allowing more defects that function as catalytic sites while promoting fast electron transfer in the N-doped carbon substrate.

A multiple Kirkendall strategy for converting nanosized zero-valent iron to highly active Fenton-like catalyst for organics degradation

Nanosized zero-valent iron (nZVI) is a promising persulfate (PS) activator, however, its structurally dense oxide shell seriously inhibited electrons transfer for O-O bond cleavage of PS. Herein, we introduced sulfidation and phosphorus-doped biochar for breaking the pristine oxide shell with formation of FeS and FePO4-containing mixed shell. In this case, the faster diffusion rate of iron atoms compared to shell components triggered multiple Kirkendall effects, causing inward fluxion of vacancies with further coalescing into radial nanocracks. Exemplified by trichloroethylene (TCE) removal, such a unique "lemon-slice-like" nanocrack structure favored fast outward transfer of electrons and ferrous ions across the mixed shell to PS activation for high-efficient generation and utilization of reactive species, as evidenced by effective dechlorination (90.6%) and mineralization (85.4%) of TCE. [Formula: see text] contributed most to TCE decomposition, moreover, the SnZVI@PBC gradually became electron-deficient and thus extracted electrons from TCE with achieving nonradical-based degradation. Compared to nZVI/PS process, the SnZVI@PBC/PS system could significantly reduce catalyst dosage (87.5%) and PS amount (68.8%) to achieve nearly complete TCE degradation, and was anti-interference, stable, and pH-universal. This study advanced mechanistic understandings of multiple Kirkendall effects-triggered nanocrack formation on nZVI with corresponding rational design of Fenton-like catalysts for organics degradation.

Carbon encapsulated FeS nanosheet-nanoribbon interwoven sandwich structure as efficient sodium-ion battery anodes

Carbon encapsulation and optimization of nanoparticle structure are key strategies in the development of battery electrode materials. Herein, we report a simple, one step chemical vapor deposition-like method to synthesize carbon encapsulated sandwich structured nanosheets/nanoribbons of ferrous sulphide (FeS@C NSRs) as a high performance sodium-ion battery anode material. The structurally advantageous FeS@C NSRs arises from heating Fe foam in the presence of a sulphur-containing resin, which supplies both the sulphur and carbon for the reaction. FeS@C NSRs maintains a high capacity of 582.8 mAh g−1 at 0.1 A g−1 for 120 cycles and a high rate capability of 270 mAh g−1 at 10 A g−1 for 2500 cycles. The impressive cycling performance results from fast electron and ion transfer with low structural strain on the bulk material. Furthermore, in situ Raman spectroscopy and XRD also reveal evidence that FeS@C NSRs cycles via a fully reversible conversion reaction pathway facilitated by the C–S–Fe bond. The efficient synthesis method could also be explored to produce other carbon coated transition metal sulphides for electrochemical applications.

Eliminating bandgap between Cu-CeO2-x heterointerface enabling fast electron transfer and redox reaction in Li-S batteries

The design of catalyst systems with reasonable configuration to alleviate the shuttle effects and strength conversion kinetics of polysulfide (LiPSs) in lithium-sulfur (Li-S) batteries still remains a challenge. Herein, a novel Cu-CeO2-x heterointerface is constructed by an ion migrating-capturing process. The Cu2+dispersed inner the carbon nanofibers (CNF) is controlled released and transferred outside gradually, and finally is captured by the CeO2 nanoparticles anchored on the CNF surface and form a Cu-CeO2-x heterointerface. Synergistically, the CeO2 capture and disperse Cu clusters as a hosting material, while the Cu decoration prevent further aggregation of CeO2 at harsh reaction conditions. Thus, the orbital interaction between CeO2 and Cu induce numerous oxygen vacancy and band gap disappearance at the heterointerface, resulting in a lower energy barrier of electron/hole separation and fast electron transfer in the metallic Cu-CeO2-x composites. Eventually, the Cu-CeO2-x can accelerate the catalytic conversion of LiPSs and decomposition of Li2S, and the Li-S cell deliver an excellent performance of 626 mA h g−1 after 800 cycles at a current density of 2 C, with a decay rate of only 0.046 % per cycle. This work reveals the formation mechanism of oxygen vacancy and disappearance of band gap at heterointerface, opening up a new prospect for rational design of various heterogeneous structures for cathode materials.

Disposable tungsten sulfide framed polydopamine nanostructure modified sensor for non-enzymatic electrochemical detection of organophosphate pesticide

Pesticide residues pose a global threat to human health, and conventional sensors cannot simultaneously detect pesticide residues on the surface and inside agricultural products. Therefore, it opens up an opportunity to develop efficient techniques for the optimal detection of pesticides residues, enhancing agricultural productivity while simultaneously reducing associated health risks This work presents a polydopamine functionalized tungsten sulfide self-assembled nanostructure (WS2-PDA) electrocatalyst capable of detecting organophosphorus paraoxon ethyl (PXL) pesticide. The structural properties of the WS2-PDA nanostructure were analyzed for their morphology, crystallinity using various microscopy and spectroscopic techniques. The electrochemical experiments involving cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were conducted to investigate the electrochemical behavior of the WS2-PDA modified screen-printed carbon electrode (SPCE) toward PXL. Intermolecular interactions of polydopamine, presenting catechol, imine and amine functional group on the WS2 ionic surface via coordination complex enhance the binding ability, leading to improved ionic conductivity, electrode activity, and a higher active surface area ensued fast electron transferability. According to the findings, the DPV cathodic peak current response of the modified electrode revealed sensitive detection of PXL, with a lower detection limit (LOD) of 0.0021 μM (S/N = 3). Following that, the electrode exhibited two linear concentration ranges from 0.01 μM to 443.09 μM, and 443.09 μM to 521.34 μM, with a sensitivity of 0.310 µA µM−1 cm2. Likewise, the proposed sensors exhibited excellent repeatability, reproducibility, and selectivity over common interferents. Subsequently, it demonstrated outstanding stability with a relative standard deviation (RSD) of < 2.24%. Finally, the WS2-PDA/SPCE sensor achieved good recovery results in the presence of water, soil, and food samples.

Metalloporphyrin based MOF-545 coupled with solid solution ZnxCd1-xS for efficient photocatalytic hydrogen production

The growing concern over the rapid consumption of fossil fuels has spurred scientists to seek environment-friendly and sustainable energy alternatives. The utilization of photocatalytic water splitting shows great potential in generating environmentally friendly hydrogen energy. Zirconium-based porphyrin MOF-545 has drawn extensive attention in photocatalysis since it has strong light absorption and fast electron transfer capability. A series of Zr-based metalloporphyrins containing different metals, MOF-545M (M = Co, Ni, Cu, Zn), were synthesized and assembled with solid solution ZnxCd1-xS (ZCS) nanoparticle to develop the corresponding of hybrid photocatalysts, ZCS/MOF-545M. Various characterizations show that introducing the porphyrin MOF-545Co not only improve the visible light response range of Zn0.5Cd0.5S (ZCS-0.5) but also enhance the carrier separation efficiency of ZCS-0.5. The carrier transfer direction during the reaction was confirmed by surface photovoltage spectroscopy and shows the formation of S-scheme. Under visible light irradiation, the hybrid photocatalyst ZCS-0.5/MOF-545Co exhibits a high H2 evolution rate of 148 μmol h−1, with increases of 52.8, 22.9 and 6.5 times than those of bare ZnS, CdS and ZCS-0.5, respectively. The present work gives a strategy for erecting S-scheme heterojunction to inhibit the photocorrosion of metal sulfides and enhancement the carrier separation efficiency.

One-Step Fabricated Sn0 Particle on S-Vacancies SnS2 to Accelerate Photoelectron Transfer for Sterling Photocatalytic CO2 Reduction in Pure Water Vapor Environment.

Promoting the proton-coupled electron transfer process in order to solve the sluggish carrier migration dynamics is an efficient way to accelerate the photocatalytic CO2 reduction (PCR) process. Herein, through the reduction of Sn4+ by amino and sulfhydryl groups, Sn0 particles are lodged in S-vacancies SnS2 nanosheets. The high conductance of Sn0 particles expedites the collection and transport of photogenerated electrons, activating the surrounding surface of unsaturated sulfur (Sx 2- ) and thus lowering the energy barrier for generation of *COOH. Meanwhile, S-vacancies boost H2 O adsorption while Sx 2- increases CO2 adsorption, as demonstrated by density functional theory (DFT), obtaining a selectivity of 97.88% CO and yield of 295.06 µmol g-1 h-1 without the addition of co-catalysts and sacrificial agents. This work provides a new approach to building a fast electron transfer interface between metal particles and semiconductors, which works in tandem with S-vacancies and Sx 2- to boost the efficiency of photocatalytic CO2 reduction to CO in pure water vapor environment.