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Preparation of interstitial carbon doped BiOI for enhanced performance in photocatalytic nitrogen fixation and methyl orange degradation
摘要： Carbon-doped BiOI (C-BiOI) photocatalysts were successfully synthesized via a hydrothermal method with Bi(NO3)3·5H2O, KI, and glucose as raw materials for the first time. The synthesized samples had excellent photocatalytic activities in the degradation of methyl orange (MO) and the reduction of N2 to NH3. To reveal the origin of the superior photoactivity, the C-BiOI was examined by multi techniques, including N2-adsorption, XRD, SEM, TEM, Raman, XPS, DRS, PL, EIS and transient photocurrent response. The characterization results indicated that the carbon clusters entered the interlayers of BiOI crystal during preparation. The doped carbon interfered the lattice periodicity and generated vacancies in the BiOI structure, resulting in the decreased band gap and increased efficiency in charge separation, both of which could significantly hasten the photocatalytic reaction. Additionally, the introduced carbon affected the morphology of BiOI and increased its specific surface area, which may also benefit the photocatalytic process. The carbon content was crucial to the promotion effect. Under visible light, the optimized carbon-doped BiOI (C-BiOI-2) presented an MO degradation rate of 0.136 min-1, which was 4.44 times higher than that of pure BiOI. However, for the photocatalytic N2 fixation, due to the contribution of surface carbon in N2 adsorption, the C-BiOI sample containing higher carbon content (C-BiOI-3) displayed superior performance than C-BiOI-2. The NH3 generation rate under simulated sunlight reached 311 μmol g?1h?1, which was about 3.7-fold of that of BiOI. This work may shed some insight into the designing and understanding of carbon-doped semiconductor photocatalysts.
关键词： interstitial doping,C-BiOI,photocatalytic N2 fixation,visible light
更新于2025-09-23 15:23:52
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In-situ approach to fabricate BiOI photocathode with oxygen vacancies: Understanding the N2 reduced behavior in photoelectrochemical system
摘要： The adsorption and activation of N2 on the catalyst surface is a major problem in the process of photoelectrochemical (PEC) N2 reduction. Herein, we report a strategy to fabricate intrinsic BiOI (I-BiOI) photocathode with oxygen vacancies (OVs) (R-BiOI) by a facile in-situ method, and the R-BiOI was successfully selected as the model matrix for understanding the role of OVs in the PEC N2 reduction system for the first time. The correlation between carrier concentration/Lewis-base/active sites and OVs was in-depth demonstrated by Mott-Schottky plots and photoelectrochemical impedance spectroscopy (PEIS) results, meanwhile the Linear-sweep-voltammetry (LSV) data further confirmed the selectivity for active N2 over R-BiOI photocathode. The tandem built from BiVO4 photoanode and R-BiOI photocathode presented the desirable production rate of ammonia at about 1.4 mmol/m2/h, which is 1.3 and 2.9 times than that of I-BiOI (1.1 mmol/m2/h) and Pt (0.48 mmol/m2/h). Our findings have initially developed the proposed mechanism for the behavior of solar-electron-ammonia conversion and offered an alternative potential route for green N2 fixation.
关键词： Active sites,Lewis-base,Oxygen vacancies,BiOI,Photoelectrochemical (PEC) N2 fixation
更新于2025-09-23 15:23:52
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An analytical method to create patient-specific deformed bone models using X-ray images and a healthy bone model
摘要： Generation of patient-specific bone models from X-ray images is useful for various medical applications such as total hip replacement, implant manufacturing, knee kinematic studies and deformity correction. These models may provide valuable information required for a more reliable operation. In this work, we propose a new algorithm for generating patient-specific 3D models of femur and tibia with deformity, using only a generic healthy bone model and some simple measurements taken on the X-ray images of the diseased bone. Using the X-ray measurements, an interpolation function (a polynomial or a cubic spline) is fit to the mid-diaphyseal curve of the actual bone and the generic bone model is deformed in the guidance of this function with free form deformation method. The created models are intended to be used mainly for the visualization of fixation procedure in software-supported external fixation systems. An error measure is defined to quantify the error in this matching procedure. The method is found to be capable of producing deformed tibia models that satisfactorily reflect the actual bones, as confirmed by two orthopaedic surgeons who use software-supported external fixation systems regularly.
关键词： Deformity,3D bone modeling,Free form deformation,External fixation,Patient-specific bone models,Mathematical modeling
更新于2025-09-23 15:21:21
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Light-Emitting Diode Power Conversion Capability and CO2 Fixation Rate of Microalgae Biofilm Cultured Under Different Light Spectra
摘要： Microalgae biofilm-based culture has attracted much interest due to its high harvest efficiency and low energy requirements. Using light-emitting diodes (LEDs) as light source for microalgae culture has been considered as a promising choice to enhance the economic feasibility of microalgae-based commodities. In this work, the LED power conversion capability and CO2 fixation rate of microalgae biofilms (Chlorella ellipsoidea and Chlorella pyrenoidosa) cultured under different light spectra (white, blue, green and red) were studied. The results indicated that the power-to-biomass conversion capabilities of these two microalgae biofilms cultured under blue and white LEDs were much higher than those under green and red LEDs (C. ellipsoidea: 32%–33% higher, C. pyrenoidosa: 34%–46% higher), and their power-to-lipid conversion capabilities cultured under blue LEDs were 61%–66% higher than those under green LEDs. The CO2 fixation rates of these two biofilms cultured under blue LEDs were 13% and 31% higher, respectively, than those under green LEDs. The results of this study have important implications for selecting the optimal energy-efficient LEDs using in microalgae biofilm-based culture systems.
关键词： biofilm-based cultivation,microalga,light spectrum,power conversion capability,CO2 fixation rate
更新于2025-09-23 15:21:01
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Synthetic biology approaches for improving photosynthesis
摘要： The phenomenal increase in agricultural yields that we have witnessed in the last century has slowed down as we approach the limits of selective breeding and optimization of cultivation techniques. To support the yield increase required to feed an ever growing population, we will have to identify new ways to boost the efficiency by which plants convert light into biomass. This challenge could be potentially tackled using state-of-the-art synthetic biology techniques to rewrite plant carbon fixation. In this review, we use recent studies to discuss and demonstrate different approaches for enhancing carbon fixation, including engineering Rubisco for higher activity, specificity, and activation; changing the expression level of enzymes within the Calvin Cycle to avoid kinetic bottlenecks; introducing carbon concentrating mechanisms such as inorganic carbon transporters, carboxysomes, and C4 metabolism; and rewiring photorespiration towards more energetically efficient routes or pathways that do not release CO2. We conclude by noting the importance of prioritizing and combining different approaches towards continuous and sustainable increase of plant productivities.
关键词： C4 metabolism,carbon concentrating mechanisms,photorespiration,Calvin Cycle,carbon fixation,Rubisco
更新于2025-09-19 17:15:36
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Graphene quantum dots modified flower like Bi2WO6 for enhanced photocatalytic nitrogen fixation
摘要： Graphene quantum dots modified Bi2WO6 (GQD/Bi2WO6) composites is applied to photocatalytic N2 fixation. The as-prepared GQD/Bi2WO6 samples showed considerable increase in photocatalytic nitrogen fixation compared to the pure Bi2WO6 and GQD. The results revealed that GQD uniformly placed on the surface of Bi2WO6 and tight junction between the two samples helped to boost the photocatalytic activity. The PL, photocurrent and EIS analyses further demonstrated that the composite had the low recombination rate of photo-generated charges. Photocatalytic nitrogen fixation test indicated that GQD/Bi2WO6 with 10 wt% GQDs exhibited the highest ammonia synthesis rate in the presence of visible light, which is 8.88-fold and 33.8-fold higher than pure Bi2WO6 and GQD. Simultaneously, the GQD/Bi2WO6 sample has high stability.
关键词： Bi2WO6,Photocatalytic N2 fixation,Graphene quantum dots
更新于2025-09-12 10:27:22
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Laser Spark Spectrometry Study of the Properties of Cotton Fabric Modified with Silver Nanoparticles and the Strength and Duration of the Antiseptic Effect
摘要： A laser spark spectrometry study was carried out on the effect of the silver content in cotton fabric on the extent and duration of the antiseptic effect. Durable antiseptic properties of various strength were found to appear only after tannide fixation of the composition in the fabric structure.
关键词： laser spark spectrometry,tannide fixation,cotton fabric,silver nanoparticles,antiseptic effect
更新于2025-09-11 14:15:04
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Density functional theory evaluation of cation-doped bismuth molybdenum oxide photocatalysts for nitrogen fixation
摘要： This study investigates the photocatalytic nitrogen fixation on a cation-doped surface (BixMy)2MoO6 where (M = Fe, La, Yb) in both the orthorhombic and monoclinic configurations using a density functional theory (DFT) approach with experimentally validated model inputs. The proceeding discussion focuses on the Heyrovsky-type reactions for both the associative and dissociative reaction pathway related to nitrogen reduction. Key fundamental insight in the reduction mechanism is discussed that relates the material properties of the substitutional ions to the nitrogen and hydrogen affinities. Physical insight is gathered through interpretation of bound electronic states at the surface. Compositional phases of higher Fe and Yb concentrations resulted in decreased MoeO binding and increased affinity between Mo and the N and H species on the surface. The modulation of the MoeO binding is induced by strain as Yb and Fe are implemented, this, in turn, shifts energy levels and modulates the band gap energy by approximately 0.2 eV. This modification of MoeO bond as substitution occurs is a result of the orbital hybridization of MeO (M = Fe, Yb) that causes a strong orbital interaction that shifts states up toward the Fermi. The optimal composition was predicted to be an orthorhombic configuration of (Bi0.75Fe0.25)2MoO6 with a predicted maximum thermodynamic energy barrier of 1.4 eV. This composition demonstrates effective nitrogen and hydrogen affinity that follows the associative or biological nitrogen fixation pathway.
关键词： Gibbs energy,Thermodynamics,Inorganic,DFT,Nitrogen fixation
更新于2025-09-11 14:15:04
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Short-Term Comparison of Surgical Results between One-Haptic and Two-Haptics Transscleral Fixation of Intraocular Lens
摘要： Purpose: To compare the short-term clinical outcomes of transscleral fixation intraocular lens (IOL) with two haptics or one haptic. Methods: We retrospectively reviewed the medical records of 26 patients with transscleral fixation of IOL (11 with one-haptic fixation, 15 with two-haptic fixation) except in patients whose visual acuity is not expected to improve due to retinal problems or ocular trauma. We analyzed the manifest refraction, visual acuity, refractive error preoperatively and postoperatively, preoperative IOL decentration, operating time, and postoperative complications. Results: When comparing the two groups preoperatively, the mean lens decentration in the one-haptic group was 2.73 ± 2.88 mm and 4.59 ± 2.18 mm in the two-haptics group. The decentration in the two-haptic group was greater than in the one-haptic group, but not significantly. Visual acuity and refractive power were not significantly different between the groups. The mean operation time (minutes) was 65.00 ± 22.69 and 93.66 ± 29.54 in the one-haptic and two-haptic groups, respectively. The operation time in the one-haptic group was significantly shorter than in the two-haptic group (p = 0.020). When comparing visual acuity preoperatively and postoperatively, both groups showed significant improvement (p < 0.01). However, refractive error and postoperative IOL decentration were similar between the groups. Conclusions: The short-term surgical results of transscleral fixation using the two surgical techniques were not different; one-haptic transscleral fixation was preferred due to shorter operation time and lower patient discomfort.
关键词： Two-haptic fixation of intraocular lens,One-haptic fixation of intraocular lens,Dislocated intraocular lens,Transscleral fixation
更新于2025-09-10 09:29:36
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TiO2 (B) nanotubes with ultrathin shell for highly efficient photocatalytic fixation of nitrogen
摘要： Photocatalytic fixation of nitrogen under the mild condition is a green and promising ammonia synthesis strategy, which however is still a big challenge due to the high activation energy for nitrogen. Herein, we report the photocatalytic fixation of nitrogen on TiO2 (B) nanotubes with large specific surface area (344m2/g), the ultrathin shell and submicrometer-sized cavity (ca. 250 nm). A high yield of 106.6 μmolg-1h-1 for NH3 under simulated sunlight irradiation was achieved at room temperature, which is 1.61 times the yield on TiO2 nanosheets. Based on the results from EPR, photoluminescence and photo-electrochemical analyses, the improved activity is attributed to the efficient nitrogen activation by the abundant surface defects and the enhanced light utilization on nanotube with the multiple light-scattering effect. Moreover, the photocatalytic activity of TiO2 (B) nanotubes can be well preserved for 4 cycles. This study provides a new approach for rational designing of efficient photocatalysts toward stable and robust nitrogen fixation in mild conditions.
关键词： defects,nitrogen fixation,TiO2 nanotube,photocatalysis
更新于2025-09-10 09:29:36