Exploration of the mechanism of levofloxacin removal by N-doped-induced interfacial micro-electric field-activated persulfate.

The defects formed by N doping always coexist with pyrrole nitrogen (Po) and pyridine nitrogen (Pd), and the synergistic mechanisms of H2O2 production and PMS activation between the different Po: Pd are unknown. This paper synthesized MOF-derived carbon materials with different nitrogen-type ratios as cathode materials in an electro-Fenton system using precursors with different nitrogen-containing functional groups. Several catalysts with different Po: Pd ratios (0:4, 1:3, 2:2, 3:1, 4:0) were prepared, and the best catalyst for LEV degradation was FC-CN (Po: Pd=3:1). X-ray Photoelectron Spectroscopy (XPS) and density-functional theory (DFT) calculations show that the introduction of nitrogen creates an interfacial micro-electric field (IMEF) in the carbon layer and the metal, accelerates the electron transfer from the carbon layer to the Co atoms, and promotes cycling between the Fe3+/Co2+ redox pairs, with the electron transfer reaching a maximum at Po: Pd = 3:1. FC-CN (Po: Pd=3:1) achieved more than 95 % LEV degradation in 90 min at pH = 3-9, with a lower energy consumption of 0.11 kWh m-3 order-1. and the energy consumption of the catalyst for LEV degradation is lower than that of those catalysts reported. In addition, the degradation pathway of LEV was proposed based on UPLC-MS and Fukui function. This study offers some valuable information for the application of MOF derivatives.

Ultrathin layer TAFC on BiVO4 with ligand-to-metal charge transfer enhances built-in electric field for boosting photoelectrochemical water oxidation.

To reveal the mechanism of charge transfer between interfaces of BiVO4-based heterogeneous materials in photoelectrochemical water splitting system, the cocatalyst was grown in situ using tannic acid (TA) as a ligand and Fe and Co ions as metal centers (TAFC), and then uniformly and ultra-thinly coated on BiVO4 to form photoanodes. The results show that the BiVO4/TAFC achieves a superior photocurrent density (4.97 mA cm-2 at 1.23 VRHE). The charge separation and charge injection efficiencies were also significantly higher, 82.0 % and 78.9 %, respectively. From XPS, UPS, KPFM, and density functional theory calculations, Ligand-to-metal charge transfer (LMCT) acts as an electron transport highway in TAFC ultrathin layer to promote the concentration of electrons towards metal center, leading to an increase in the work function, which enhances the built-in electric field and further improves the charge transport. This study demonstrated that the LMCT pathway on TA-metal complexes enhances the built-in electric field in BiVO4/TAFC to promote charge transport and thus enhance water oxidation, providing a new understanding of the performance improvement mechanism for the surface-modified composite photoanodes.

Anthraquinone-based polymer modified BiVO4 photoanode with strong electron-withdrawing functional groups for boasting photoelectrochemical water oxidation.

The photoelectrochemical (PEC) performance ofBiVO4 is limited by sluggish water oxidation kinetics and severe carrier recombination. Herein, a novel high-performance BiVO4/NiFe-NOAQ photoanode is prepared by a simple one-step hydrothermal method, using BiVO4 and 1-Nitroanthraquinone (NOAQ) as raw materials. The BiVO4/NiFe-NOAQ photoanode has an excellent photocurrent density of 5.675 mA cm-2 at 1.23 VRHE, which is 3.35 times higher than that of the pure BiVO4 (1.693 mA cm-2) photoanode. The BiVO4/NiFe-NOAQ shows a significant improvement in charge separation efficiency (86.12 %) and charge injection efficiency (87.86 %). The improvement is ascribable to the NiFe-NOAQ form a type II heterojunction with BiVO4 to inhibit carrier recombination. More importantly, the kinetic isotope experiment suggests that the proton-coupled electron transfer (PCET) process can enhance the charge transfer of BiVO4/NiFe-NOAQ. The contact angle measurements show that modifying functional groups enhanced the hydrophilicity of BiVO4/NiFe-NOAQ, which can further accelerate the PCET process. The XPS and PL results as well as the tauc plot indicate that the strong electron-withdrawing ability of -NO2 which can promote the extension of π conjugation, results in more π electron delocalization and produces more efficient active sites, thus achieving efficient photoelectrochemical water oxidation.

Strain Engineering of Cd0.5 Zn0.5 S Nanocrystal for Efficient Photocatalytic Hydrogen Evolution from Wasted Plastic.

The challenge of synthesizing nanocrystal photocatalysts with adjustable lattice strain for effective waste-to-energy conversion is addressed in this study. Cd0.5 Zn0.5 S (CZS) nanocrystals are synthesized by a simple solvothermal method, regulation of the ratio between N, N-dimethylformamide, and water solvent are shown to provoke expansion and contraction, inducing an adjustable lattice strain ranging from -1.2% to 5.6%. With the hydrolyzed wasted plastic as a sacrificial agent, the 5.6% lattice-strain CZS exhibited a robust hydrogen evolution activity of 1.09 mmol m-2  h-1 (13.83 mmol g-1  h-1 ), 4.5 times that of pristine CZS. Characterizations and density functional theory calculation demonstrated that lattice expansion increases the spatial distance between the valence band maximum and conduction band minimum, thus reducing carrier recombination and promoting charge transfer. Additionally, lattice expansion induces surface S vacancies and adsorbed OH groups, further enhancing redox reactions. This study focuses on the synchronous regulation of crystal structure, charge separation/transport, and surface reactions through lattice strain engineering, which providing a reference for the rational design of new photocatalysts for effective waste-to-energy conversion.

Electrochemical surface reconstruction of Prussian blue-modified nickel sulfide to form iron-nickel bilayer hydroxyl oxides for efficient and stable oxygen evolution reaction processes.

The oxygen evolution reaction (OER) is an important semi-reaction in the electrocatalytic water splitting for hydrogen energy production, and the development of efficient and low-cost electrocatalysts to solve the problem of slow 4-electron transport kinetics in the OER process is key. In this work, a pre-electrocatalyst with the heterogeneous interfacial structure, Prussian blue-modified nickel sulfide with sulfur vacancies (PB/NS-Sv), was designed and then converted to iron-nickel bilayer hydroxyl oxides in oxygen-rich vacancies (FeOOH/NiOOH-Ov@NS) through electrochemical oxidative reconstruction to obtain a truly stable and efficient active material. The study utilized in situ Raman to observe the transition from PB/NS-Sv to FeOOH/NiOOH-Ov@NS during the reaction. The electronic density of states in FeOOH/NiOOH-Ov@NS is regulated by the bilayer hydroxyl metal oxide synergistic effect and the abundant oxygen defect of Mental-OOH-Ov, which significantly improves OER catalytic performance. FeOOH/NiOOH-Ov@NS requires a low overpotential of only 257 mV in 1 mol/L KOH at 100 mA cm-2 current density, has a small Tafel slope of 35.2 mV dec-1 and has excellent stability for 150 h at 100 mA cm-2 current density, making it a promising candidate for industrial applications.

Redox-active ligands enhance oxygen evolution reaction activity: Regulating the spin state of ferric ions and accelerating electron transfer.

Metal-organic frameworks (MOFs) are considered as one of the most promising catalysts for oxygen evolution reaction (OER). However, only a few have introduced redox-active ligands into MOFs and explored their role in the OER process. In this work, we synthesized FeNi DHBQ/NF using the redox-active ligand 2,5-dihydroxy-1,4-benzoquinone (DHBQ), which exhibited excellent redox activity and required only 207 and 242 mV overpotentials to achieve current densities of 10 and 100 mA cm-2. Our research confirms that (i) the doping of Fe leads to the formation of Ni â†’ O â†’ Fe electron transfer channels in the MOFs and stronger electron transfer, attributed to the stronger d-π conjugation between the metal center and the ligand and reduced the d-orbital crystal field splitting energy of Fe3+; (ii) the rate determination step (RDS) in the OER process of the catalyst is the formation of O*, while Fe and redox-active ligands effectively regulate the adsorption energy of oxygen-containing intermediates, reducing the energy barrier of the RDS; (iii) the redox-active ligands can act as "electron reservoirs" in the electrochemical process, making Ni more readily oxidized to Ni3+ or even Ni4+ at low potentials, which is beneficial to the subsequent OER process.

Investigation for Anxiety and Depression Situation in Couples Receiving in vitro Fertilization and Embryo Transfer (IVF-ET) with Donor Sperm and Associated Influencing Factors.

Background: This study aimed to explore the current situation of anxiety and depression on day of transfer in couples receiving in vitro fertilization and embryo transfer (IVF-ET) with donor sperm and analyze its influencing factors. Methods: This study selected 187 IVF-ET administered couples who received donor sperm from our Hospital from August 2021 to July 2022. On the day of IVF-ET with donor sperm transplantation, patients were investigated with general data questionnaire, self-rating anxiety scale (SAS) and self-rating depression scale (SDS) to analyze their anxiety and depression scores and their influencing factors. Results: Scores of anxiety and depression on the day of transplantation in patients receiving IVF-ET with donor sperm were 43.98±6.80 and 46.03±10.61 respectively, which were higher compared to levels of Chinese health norm (P<0.05). The anxiety score of patients' spouses was 41.23±6.69 and depression score was 44.23±11.65, which were higher compared to levels of Chinese health norm (P<0.05). Score of anxiety and depression of women was significantly higher compared to those of their spouse (P<0.05). Anxiety and depression scores of women in non-pregnant group were significantly higher compared to those in pregnant group (P<0.05). Regression analysis showed that education level and annual family income were influencing factors of anxiety and depression scores of IVF-ET with donor sperm couples on the day of transfer, and number of eggs taken and transfer times were influencing factors of depression scores of IVF-ET with donor sperm patients on the day of transfer. Conclusion: Psychological state of couples receiving IVF-ET with donor sperm was significantly affected, especially in female side. Medical staff should focus on patients with low education level, low family income, and more times of transfer and egg retrieval, and take targeted intervention measures to keep them in good psychological state, which is conducive to improving pregnancy outcome.

Adjusting the valence band center of Co-Ni-bimetallic sulfides through lattice expansion and stacking faults triggered by strain engineering to boost oxygen evolution reaction.

Stress engineering can improve catalytic performance by straining the catalyst lattice. An electrocatalyst, Co3S4/Ni3S2-10%Mo@NC, was prepared with abundant lattice distortion to boost oxygen evolution reaction (OER). With the assistance of the intramolecular steric hindrance effect of metal-organic frameworks, slow dissolution by MoO42- of the Ni substrate and recrystallization of Ni2+ was observed in the process of Co(OH)F crystal growth with mild temperature and short time reaction. The lattice expansion and stacking faults created defects inside the Co3S4 crystal, improved the material conductivity, optimized the valence band electron distribution of the material, and promoted the rapid conversion of the reaction intermediates. The presence of reactive intermediates of the OER under catalytic conditions was investigated using operando Raman spectroscopy. The electrocatalysts exhibited super high performance, a current density of 10 mA cm-2 at an overpotential of 164 mV and 100 mA cm-2 at 223 mV, which were comparable to those of integrated RuO2. Our work for the first time demonstrates that the dissolution-recrystallization triggered by strain engineering is a good modulation approach to adjust the structure and surface activity of catalyst, suggesting promising industrial application.

Amorphous dominated metal hydroxide-organic framework with compositional and structural heterogeneity for enhancing anodic electro-oxidation reactions.

Inorganic-organic hybrids are promising anode catalysts to realize high activity and stability. Herein, an amorphous-dominated transition metal hydroxide-organic framework (MHOF) with isostructural mixed-linker was successfully synthesized on nickel foam (NF) substrate. The designed IML24-MHOF/NF exhibited remarkable electrocatalytic activity with an ultralow overpotential of 271 mV for oxygen evolution reaction (OER) and a potential of 1.29 V vs. reversible hydrogen electrode for urea oxidation reaction (UOR) at 10 mA·cm-2. Furthermore, the IML24-MHOF/NF||Pt-C cell required only 1.31 V for urea electrolysis at 10 mA·cm-2, which was much smaller than traditional water splitting (1.50 V). When coupled with UOR, the hydrogen yield rate was faster (1.04 mmol·h-1) than with OER (0.32 mmol·h-1) at 1.6 V. The structure characterizations, together with operando monitoring, including operando Raman, Fourier transform infrared, electrochemical impedance spectroscopy, and alcohol molecules probe, revealed that: (1) amorphous IML24-MHOF/NF prefers self-adaptive reconstruction into active intermediate species against the external stimulus; (2) pyridine-3,5-dicarboxylate-incorporation into parent framework reconfigures electronic structure of system, thus mediating the absorption of oxygen-containing reactants during anodic oxidation reactions, such as O* and COO*. This work provides a new approach for boosting the catalytic activity of anodic electro-oxidation reactions by trimming the structure of MHOF-based catalysts.

Unraveling the π-interaction of NiFe-based metal-organic frameworks with enhanced oxygen evolution: Optimizing electronic structure and facilitating electron transfer modulation.

Metal-organic frameworks (MOFs) with conjugation carboxylate ligands as electrocatalysts can significantly improve oxygen evolution reaction (OER), but the role of π-interaction on the reactive sites of OER is often neglected. We intend to unravel the mechanism of how π-interaction enhances OER performance. The results of Rietveld refinement, density functional theory (DFT) calculations, and in-situ Raman spectra show that π-interaction can efficiently modulate the local spin configuration of metal centers, facilitate γ-Ni1-xFexOOH active species with high-valence Ni sites modified by high-spin Fe, accelerate electron transfer, optimize the d-band center together with the beneficial rate-determining step of OER. NiFe-BPDC MOFs/NF with 0.8559 eV π-interaction energy generated γ-Ni1-xFexOOH in only 60 s at 1.4 V, demonstrating that π-interaction promotes the rapid generation of highly active reactive sites. Furthermore, the results of in-situ Raman and electron paramagnetic resonance (EPR) spectra reveal that the deprotonation and deoxygenation steps of OER are accompanied by changes in the oxidation state of metal ions and the generation of oxygen vacancies on the surface of catalysts. In addition, NiFe-BPDC MOFs/NF rapidly completes the deprotonation and deoxygenation steps, and it requires only 288 mV overpotential to reach 100 mA/cm2 with 100 h of stability, suggesting promising industrial application.

Microelectronic structure changes electron utilization: Core-shell structure catalysts with electron library and quantum dots for photocatalytic hydrogen production.

Photocatalysis is facing huge challenges especially the separation and efficient utilization of photocarriers. Herein, we report that a ternary hollow core-shell photocatalyst is synthesized by template and self-assembled method. The experimental results show that the electron separation efficiency and utilization efficiency are significantly improved, not only because the ternary hollow core-shell structure spatially separates the oxidation area MnOx from the reduction area Co-MOF, but also because lots of emergent electrons are stored in Co-MOF as an electronic library, contributing to the formation of surface polarization to support the requirement call from the CoP quantum dots (QDs) as active-sites. It's the first report that the effectively separated electron-rich and electron-poor microelectronic states of the tunable Co-MOF promotes electron utilization by affecting the storage capacity of the electron library promoting photocatalytic hydrogen production. The tests show that Mn@Cd-CoP QDs/MCN (35.31 mmol/h/g), Mn@Cd-CoP QDs/BCN (23.69 mmol/h/g) and Mn@Cd-CoP QDs (11.08 mmol/h/g) have the better hydrogen production performances, which is about 38 times, 26 times and 12 times higher than CdS (0.9244 mmol/h/g), respectively. The pioneering exploration about the ternary hollow core-shell structure bonded with MOFs materials with abundant CoP QDs will open up a new perspective to design high-performance for solar-chemical energy conversion.

Lattice distortion of crystalline-amorphous nickel molybdenum sulfide nanosheets for high-efficiency overall water splitting: libraries of lone pairs of electrons and in situ surface reconstitution.

Lattice distortion is an important way to improve the electrocatalytic performance and stability of two-dimensional transition metal materials (2d-TMSs). Herein, a lattice distortion nickel-molybdenum sulfide electrocatalyst on foam nickel (NiMoS4-12/NF) has been synthesized through a novel, simple, and effective crystalline-amorphous strategy. The electrocatalyst only requires 1.47 V to obtain 10 mA cm-2 for overall water splitting (OWS) and can function stably for 100 h at a current density of 100 mA cm-2, demonstrating an excellent electrocatalytic performance and stability. From the results of the transmission electron microscopy (TEM) and electron paramagnetic resonance spectroscopy (EPR), it can be seen that the (104) crystal lattice of NiMoS4-12 undergoes interface strain under the crystalline-amorphous state, resulting in rich sulfur defects caused by lattice distortion, which could improve the intrinsic catalytic activity of NiMoS4-12. According to the differential charge density analysis, around the sulfur defects, the Mo and Ni atoms with abundant lone pairs of electrons acted as libraries of lone pairs of electrons to enable an efficient hydrogen evolution reaction (HER). From the total density of states (TDOS) and the Gibbs free energy of hydrogen adsorption (ΔGH*), the libraries of lone pairs of electrons not only effectively optimized the distribution of the surface electron density of states at the Fermi level, but also reduced the ΔGH*, thereby improving the intrinsic HER electrocatalytic performance. The in situ Raman test results demonstrate that during the oxygen evolution reaction (OER), the surface of the nickel molybdenum sulfide was reconstructed, and highly active Ni-OOH was generated. From the calculated free energy diagrams, the Ni-OOH could optimize the reaction barrier of the rate-determining step (RDS) for the OER to enhance the slow oxygen evolution reaction kinetics. This work will contribute to the rational design of a 2d-TMSs electrocatalyst, as well as investigation of the catalytic mechanism.

Double MOF gradually activated S bond induced S defect rich MILN-based Co(z)-NiMoS for efficient electrocatalytic overall water splitting.

Herein, cactus like nanorods with rich S defects and functional group MILN-based Co(z)-NiMoS are synthesized through a facile method. First, we prepared MIL-88B precursor to give a fairly dispersed frame structure, and then Con+ was doped into disulfides, which are rich in sulfur bonds, and the imidazole group was cleverly connected into graphitized carbon via self-etching of ZIF-67. The doping of Con+ and functional groups makes tiny changes in the sulfide lattice, which promotes the unsaturation degree of the S bond and activates it gradually. The prepared semi frame sulfide with a unique structure, on the one hand, ensures the hydrophilicity and multiple active specific surface area, which lays superior functions in morphology. On the other hand, coupling metals that have strong valence change ability and functional groups by active S bonds play an important role in the process of electrocatalytic reaction. Amazingly, disintegration and self-reconstruction of MILN-based Co(z)-NiMoS occurs during oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to the activation of the S bond, which provides a new perspective for the overall water splitting mechanism. The electrochemical results show that the MILN-based Co(z)-NiMoS electrocatalyst exhibits overpotentials of HER, OER, and overall water splitting (OWS) to be 169 mV, 170 mV, and 1.466 V, respectively, making it a promising electrode material for OWS applications.

3D-Stretched Film Ni3 S2 Nanosheet/Macromolecule Anthraquinone Derivative Polymers for Electrocatalytic Overall Water Splitting.

For the first time, a new polymer electrode AQS/S is prepared by compositing Ni3 S2 nanosheets and macromolecular anthraquinone derivative (AQD) supported on nickel foam with flying colors. The AQS/S exhibits high crystalline structure and abundant S defects. Density of state calculation shows that AQD has stable internal bonding and easy external bonding with metals, conducive to the dispersion of metal reaction sites, ensuring excellent activity and high stability. Under 1.0 m KOH solution, ultralow overpotentials of 62 and 133 mV at 10 mA cm-2 on AQS/S for hydrogen evolution reaction and on activated AQS/S (A-AQS/S) for oxygen evolution reaction, respectively, are achieved. 100 h chronopotentiometry and the cyclic voltammetry tests show that catalysts have high durability. The AQS/S‖A-AQS/S two-electrode system is also found to have good electrocatalytic activity for 1.43 V to get 10 mA cm-2  in overall water splitting, better than the state-of-the-art 20% Pt/C‖RuO2 combination.

Effects of chromosomal abnormalities on pregnancy outcomes in female undergoing artificial insemination with donor's sperm.

ABSTRACT: This study aimed to evaluate the clinical characteristics, pregnancy outcomes and prognostic factors for pregnancy of female with chromosomal abnormalities (CAs) after artificial insemination with donor's sperm (AID) treatment.A retrospective case-control study was analyzed by using the data of 29 female patients with CA and 116 controlled patients with normal karyotype (1:4 ratio) who underwent AID cycles at Guangdong Family Planning Special Hospital from January 2011 to December 2017. In all cases, reproductive histories were collected, and the cytogenetic analysis was performed by Trypsin-Giemsa banding and karyotyping. The embryos were fertilized via intracervical or intrauterine insemination. Clinical characteristic variables were compared.The prevalence of CA was found to be 0.29% in the whole AID population. The live birth rates of CA group and controlled group were 41.4% and 31.0% (P = .29) respectively. Compared to normal karyotype group, patients with CA showed higher rate of primary infertility (93.1% vs 75.9%, P = .049); Multivariate analysis demonstrated that ovarian stimulation (odds ratio, 3.055; 95% confidence interval, 1.421-6.568; P = .004) was associated with adverse pregnancy outcomes in female patients with AID treatment.For the infertility CA patients who were phenotypically normal, AID was a suitable choice, whereas ovarian stimulation results in an improvement in the pregnancy rate.

Sulfur defect rich Mo-Ni3S2 QDs assisted by O-C[double bond, length as m-dash]O chemical bonding for an efficient electrocatalytic overall water splitting.

Developing earth-abundant and highly efficient electrocatalysts is critical for further development of a system. The metal (M) doping strategy and inorganic/organic composite are two common strategies to improve the performance of electrocatalysts for overall water splitting (OWS). In this paper, two strategies are subtly used to prepare Mo-Ni3S2 quantum dots (QDs) with rich sulfur defects through Mon+ doping Ni3S2 and introduction of trisodium citrate by a two-step hydrothermal reaction. Results show that high sulfur defects can be controllably prepared as the lattice mismatch and active sites can be efficiently increased via Mon+ doping. Moreover, the introduction of trisodium citrate with carboxyl functional groups not only enhances the degree of sulfur defects around the metal center, changes the morphology of sulfide to distribute the active centers evenly, but also endow the metal center with strong valence changing ability with organic characteristics. The in situ Raman study reveals that O-C[double bond, length as m-dash]O promotes the formation of the real active site M-OOH by the way of self-sacrifice during the OER process. Mo-Ni3S2 QDelectrocatalyst shows excellent performance in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), achieving a current density of 10 mA cm-2 at the overpotentials of 115 mV and 222 mV with very good chemical stability, superior than that of most of the reported materials. The OWS reaction can provide a current density of 10 mA cm-2 and 50 mA cm-2, which only needs 1.53 V and 1.74 V with excellent industrial application prospects.

Thermal field study of ceramic slot microwave ablation antenna based on specific absorption rate distribution function.

OBJECTIVE: The objective was to investigate the law of three-dimensional thermal field radiation of ceramic slot microwave (CSMW) ablation antenna. MATERIALS AND METHODS: First, microwave ablation experiments were performed with phantom and temperature data were collected. Second, the specific absorption rate distribution function of microwave (MW) ablation antenna was fit. Third, the MW ablation thermal field morphology was simulated based on the rapid simulation method. In addition, to determine the thermal field simulation accuracy, comparative analysis on the ablation morphology of forty clinical patients with liver cancer receiving percutaneous treatment was conducted. RESULTS: Regarding the ablation morphology, the CSMW ablation antenna had greater long and transverse diameters and ablation volume than the polytetrafluoroethylene slot microwave (PSMW) ablation antenna (P < 0.05). Compared with the actual ablation morphology in clinical practice, the error rate in long and transverse diameters of the simulated morphology of thermal field was up to 5% and the minimum was 1.2%, whereas the maximum volume error rate was up to 9.8%. CONCLUSION: The CSMW ablation antenna had a greater long diameter, transverse diameter, and volume regarding the ablation morphology than the PSMW ablation antenna, and the thermal field morphology obtained based on the rapid simulation algorithm had a high accuracy.

CoP QD anchored carbon skeleton modified CdS nanorods as a co-catalyst for photocatalytic hydrogen production.

An important strategy to improve the performance of catalysts is loading nanoparticle co-catalysts of better dispersion and conductivity. In this work, the ZIF-67-derived CoP quantum dot (QD) anchored graphitized carbon skeleton as a co-catalyst is loaded on CdS nanorods (NRs), while the CoP QDs derived from ZIF-67 are anchored to the carbon skeleton under phosphation and carbonization simultaneously. The porous, graphitized carbon skeleton can not only disperse CoP QDs, increasing active sites for the hydrogen reduction reaction, but also provide electron transfer channels, promoting electron transfer and increasing conductivity. In addition, the metallicity of CoP QDs makes it possible to form Schottky junctions, which is beneficial to the electron transfer at the interface. The results show that the composite photocatalyst can extensively improve the photocatalytic activity and stability, the H2 production rate is 104 947 µmol h-1 g-1 under visible light irradiation (λ ≥ 400 nm), up to 55.2 times that of bare CdS NRs, the apparent quantum yield (AQY) reaches a high value of 32.16% at 420 nm, and the structure of the photocatalyst did not change after the reaction. This work provides an innovative method for the preparation of highly efficient noble metal-free photocatalysts for the conversion of solar energy into hydrogen energy, which has bright prospects in industrial application.

Oxygen deficiency introduced to Z-scheme CdS/WO3-x nanomaterials with MoS2 as the cocatalyst towards enhancing visible-light-driven hydrogen evolution.

An oxygen deficiency modified Z-scheme CdS/WO3-x nanohybrid with MoS2 as the cocatalyst was synthesized by a microwave hydrothermal method and was used for photocatalytic hydrogen production under visible light irradiation. Loadings of WO3-x and MoS2 as well as the synthesis time of the microwave-assisted hydrothermal process were optimized, and the physicochemical and optical properties of the as-prepared photocatalysts were characterized by various techniques. Results showed that the material with 30 wt% of WO3-x, 0.1 wt% of MoS2 and a preparation time of 120 minutes exhibited the most desirable morphology and structure for hydrogen production. The maximum hydrogen production of 2852.5 µmol g-1 h-1 was achieved, which was 5.5 times that of pure CdS (519.1 µmol g-1 h-1) and 1.5 times that of CdS/30 wt% WO3-x (1879.0 µmol g-1 h-1), and the external quantum efficiency (EQE) reached 10.0% at 420 nm. The improvement of photocatalytic performance could be attributed to the Z-scheme formed between CdS and WO3-x and MoS2 as an electron trap. It is worth mentioning that the size of the composite had a negative correlation with the H2 production rate.