Analysis of Thermophysical Properties of Electro Slag Remelting and Evaluation of Metallographic Cleanliness of Steel.

Improving the competitiveness of steel companies is linked to sustainable, quality-compliant steel production. Therefore, new steel production technologies contributing to increased cleanliness of steel are continuously being developed and optimized. One way to achieve a high steel quality is to use electro slag remelting (ESR) technology. In this paper, the principle of ESR technology and the importance of fused slags for optimizing the process are outlined. The aim of this work was to analyze the main thermophysical properties of steel and fused slags used in the ESR process. Determination of the properties of steel and slags was performed using the FactSage calculation software, which involved the calculation of the liquid and solid temperature of steel and slags, the calculation and construction of quaternary diagrams, and the calculation of viscosity. The resulting quaternary diagrams revealed the substantial influence of chemical composition on melting temperatures of slags. In order to validate the acquired results, a CrNiMoV-type steel was subjected to investigation of its metallographic cleanliness and evaluation of its mechanical properties; the ESR process was shown to significantly improve the cleanliness of the steel and improve the mechanical properties of the steel compared to its cleanliness and quality when produced via vacuum degassing (VD) technology. During the ESR process, the average size of non-metallic inclusions was reduced from 20 µm to 10 µm, and the maximum size of non-metallic inclusions was reduced from 50 µm to 28 µm. The mechanical properties of the steel produced using ESR technology were impacted as follows: the ductility increased by 10%, contraction increased by 18%, notched toughness at 20 °C increased by 46%, and at -40 °C (respectively -50 °C) it increased by 30%.

A Non-Metallic Nanozyme Ameliorates Pulmonary Hypertension Through Inhibiting ROS/TGF-ß1 Signaling.

Pulmonary hypertension (PH) is a life-threatening cardiovascular disease with a lack of effective treatment options. Nanozymes, though promising for PH therapy, pose safety risks due to their metallic nature. Here, a non-metallic nanozyme is reported for the treatment of monocrotaline (MCT)-induced PH with a therapeutic mechanism involving the ROS/TGF-ß1 signaling. The synthesized melanin-polyvinylpyrrolidone-polyethylene glycol (MPP) nanoparticles showcase ultra-small size, excellent water solubility, high biocompatibility, and remarkable antioxidant capacity. The MPP nanoparticles are capable of effectively eliminating ROS in isolated pulmonary artery smooth muscle cells (PASMCs) from PH rats, and significantly reduce PASMC proliferation and migration. In vivo results from a PH model demonstrate that MPP nanoparticles significantly increase pulmonary artery acceleration time, decrease wall thickening and PCNA expression in lung tissues, as evidenced by echocardiograpy, histology and immunoblot analysis. Additionally, MPP nanoparticles treatment improve running capacity, decrease Fulton index, and attenuate right ventricular fibrosis in MCT-PH rats by using treadmill test, picrosirius red, and trichrome Masson staining. Further transcriptomic and biochemical analyses reveal that inhibiting ROS-driven activation of TGF-ß1 in the PA is the mechanism by which MPP nanoparticles exert their therapeutic effect. This study provides a novel approach for treating PH with non-metallic nanozymes based on a well-understood mechanism.

Metal-based nanoparticle in cancer treatment: lessons learned and challenges.

Cancer, being one of the deadliest diseases, poses significant challenges despite the existence of traditional treatment approaches. This has led to a growing demand for innovative pharmaceutical agents that specifically target cancer cells for effective treatment. In recent years, the use of metal nanoparticles (NPs) as a promising alternative to conventional therapies has gained prominence in cancer research. Metal NPs exhibit unique properties that hold tremendous potential for various applications in cancer treatment. Studies have demonstrated that certain metals possess inherent or acquired anticancer capabilities through their surfaces. These properties make metal NPs an attractive focus for therapeutic development. In this review, we will investigate the applicability of several distinct classes of metal NPs for tumor targeting in cancer treatment. These classes may include gold, silver, iron oxide, and other metals with unique properties that can be exploited for therapeutic purposes. Additionally, we will provide a comprehensive summary of the risk factors associated with the therapeutic application of metal NPs. Understanding and addressing these factors will be crucial for successful clinical translation and to mitigate any potential challenges or failures in the translation of metal NP-based therapies. By exploring the therapeutic potential of metal NPs and identifying the associated risk factors, this review aims to contribute to the advancement of cancer treatment strategies. The anticipated outcome of this review is to provide valuable insights and pave the way for the advancement of effective and targeted therapies utilizing metal NPs specifically for cancer patients.

Design of NiCoP nanorod loaded on cocoon carbon substrate and its non-metal doping for efficient hydrogen evolution.

The quest for effective and sustainable electrocatalysts for hydrogen evolution is crucial in advancing the widespread use of H2. In this study, we utilized silkworm cocoons as the source material to produce porous N-doped carbon (PNCC) substrates through a process involving degumming and annealing. Subsequently, NiCoP nanorod (NiCoP@PNCC) is deposited onto the substrates via a simple impregnation and calcination method to enhance the catalytic performance for the hydrogen evolution reaction (HER). The optimal spacing between the silk fibers of PNCC facilitates longitudinal growth, increases the active surface area, and balances the adsorption and desorption of reaction intermediates, thereby accelerating HER kinetics. Consequently, NiCoP@PNCC demonstrates impressive performance, with 44 mV overpotential to achieve a current density of 10 mA cm-2. Additionally, density functional theory (DFT) calculations reveal that the electronic structure and energy band of NiCoP@PNCC can be modified through the doping of elements such as B, C, N, O, F, and S. In addition, with the electronegativity enhancement of the doping elements, the interaction between Co atoms in NiCoP@PNCC and O atoms in adsorbed H2O molecules gradually enhanced, which is conducive to the dissociation of water in alkaline solution. This research introduces a novel approach for fine-tuning the catalytic activity of transition metal phosphides.

Progress Made in Non-Metallic-Doped Materials for Electrocatalytic Reduction in Ammonia Production.

The electrocatalytic production of ammonia has garnered considerable interest as a potentially sustainable technology for ammonia synthesis. Recently, non-metallic-doped materials have emerged as promising electrochemical catalysts for this purpose. This paper presents a comprehensive review of the latest research on non-metallic-doped materials for electrocatalytic ammonia production. Researchers have engineered a variety of materials, doped with non-metals such as nitrogen (N), boron (B), phosphorus (P), and sulfur (S), into different forms and structures to enhance their electrocatalytic activity and selectivity. A comparison among different non-metallic dopants reveals their distinct effects on the electrocatalytic performance for ammonia production. For instance, N-doping has shown enhanced activity owing to the introduction of nitrogen vacancies (NVs) and improved charge transfer kinetics. B-doping has demonstrated improved selectivity and stability, which is attributed to the formation of active sites and the suppression of competing reactions. P-doping has exhibited increased ammonia generation rates and Faradaic efficiencies, likely due to the modification of the electronic structure and surface properties. S-doping has shown potential for enhancing electrocatalytic performance, although further investigations are needed to elucidate the underlying mechanisms. These comparisons provide valuable insights for researchers to conduct in-depth studies focusing on specific non-metallic dopants, exploring their unique properties, and optimizing their performance for electrocatalytic ammonia production. However, we consider it a priority to provide insight into the recent progress made in non-metal-doped materials and their potential for enabling long-term and efficient electrochemical ammonia production. Additionally, this paper discusses the synthetic procedures used to produce non-metal-doped materials and highlights the advantages and disadvantages of each method. It also provides an in-depth analysis of the electrochemical performance of these materials, including their Faradaic efficiencies, ammonia yield rate, and selectivity. It examines the challenges and prospects of developing non-metallic-doped materials for electrocatalytic ammonia production and suggests future research directions.

Superhydrophobic Non-Metallic Surfaces with Multiscale Nano/Micro-Structure: Fabrication and Application.

Multiscale nano/micro-structured surfaces with superhydrophobicity are abundantly observed in nature such as lotus leaves, rose petals and butterfly wings, where microstructures typically reinforce mechanical stability, while nanostructures predominantly govern wettability. To emulate such hierarchical structures in nature, various methods have been widely applied in the past few decades to the manufacture of multiscale structures which can be applied to functionalities ranging from anti-icing and water-oil separation to self-cleaning. In this review, we highlight recent advances in nano/micro-structured superhydrophobic surfaces, with particular focus on non-metallic materials as they are widely used in daily life due to their lightweight, abrasion resistance and ease of processing properties. This review is organized into three sections. First, fabrication methods of multiscale hierarchical structures are introduced with their strengths and weaknesses. Second, four main application areas of anti-icing, water-oil separation, anti-fog and self-cleaning are overviewed by assessing how and why multiscale structures need to be incorporated to carry out their performances. Finally, future directions and challenges for nano/micro-structured surfaces are presented.

Effect of Morphology Modification of BiFeO3 on Photocatalytic Efficacy of P-g-C3N4/BiFeO3 Composites.

This current study assessed the impacts of morphology adjustment of perovskite BiFeO3 (BFO) on the construction and photocatalytic activity of P-infused g-C3N4/U-BiFeO3 (U-BFO/PCN) heterostructured composite photocatalysts. Favorable formation of U-BFO/PCN composites was attained via urea-aided morphology-controlled hydrothermal synthesis of BFO followed by solvosonication-mediated fusion with already synthesized P-g-C3N4 to form U-BFO/PCN composites. The prepared bare and composite photocatalysts' morphological, textural, structural, optical, and photocatalytic performance were meticulously examined through various analytical characterization techniques and photodegradation of aqueous rhodamine B (RhB). Ellipsoids and flakes morphological structures were obtained for U-BFO and BFO, and their effects on the successful fabrication of the heterojunctions were also established. The U-BFO/PCN composite exhibits 99.2% efficiency within 20 min of visible-light irradiation, surpassing BFO/PCN (88.5%), PCN (66.8%), and U-BFO (26.1%). The pseudo-first-order kinetics of U-BFO/PCN composites is 2.41 × 10-1 min-1, equivalent to 2.2 times, 57 times, and 4.3 times of BFO/PCN (1.08 × 10-1 min-1), U-BFO, (4.20 × 10-3 min-1), and PCN, (5.60 × 10-2 min-1), respectively. The recyclability test demonstrates an outstanding photostability for U-BFO/PCN after four cyclic runs. This improved photocatalytic activity exhibited by the composites can be attributed to enhanced visible-light utilization and additional accessible active sites due to surface and electronic band modification of CN via P-doping and effective charge separation achieved via successful composites formation.

Bandgap prediction of non-metallic crystals through machine learning approach.

The determination of bandgap is the heart of electronic structure of any material and is a crucial factor for thermoelectric performance of it. Due to large amount to data (features) that are related to bandgap are now a days available, it is possible to make use of machine learning (ML) approach to predict the bandgap of the material. The study commences by selecting the feature through Pearson correlation study between bandgap and various thermoelectric parameters in non-metallic crystals. Among the 42 parameters available in the dataset, the Seebeck coefficient and its corresponding temperatures show high correlation with the bandgap. With these three selected features we have used different ML models like multilinear regression, polynomial regression, random forest regression and support vector regression to predict the bandgap. Amongst the different ML models considered, random forest regression outperforms the other models to predict the bandgap withR2value of 97.55% between actual bandgap and predicted bandgap.

Control of the Composition and Morphology of Non-Metallic Inclusions in Superduplex Stainless Steel.

Duplex stainless steel is a unique material for cast products, the use of which is possible in various fields. With the same chemical composition, melting, casting and heat treatment technology, pitting and crevice corrosion were observed at the interphase boundaries of non-metallic inclusions and the steel matrix. To increase the cleanliness of steel, it is necessary to carefully select the technology for deoxidizing with titanium or aluminum, as the most common deoxidizers, and the technology for modifying with rare earth metals. In this work, a comprehensive analysis of the thermodynamic data in the literature on the behavior of oxides and sulfides in this highly alloyed system under consideration was performed. Based on this analysis, a thermodynamic model was developed to describe their behavior in liquid and solidified duplex stainless steels. The critical concentrations at which the existence of certain phases is possible during the deoxidation of DSS with titanium, aluminum and modification by rare earth metals, including the simultaneous contribution of lanthanum and cerium, was determined. Experimental ingots were produced, the cleanliness of experimental steels was assessed, and the key metric parameters of non-metallic inclusions were described. In steels deoxidized using titanium, clusters of inclusions with a diameter of 84 microns with a volume fraction of 0.066% were formed, the volume fraction of which was decreased to 0.01% with the subsequent addition of aluminum. The clusters completely disappeared when REMs were added. The reason for this behavior of inclusions was interpreted using thermodynamic modeling and explained by the difference in temperature at which specific types of NMIs begin to form. A comparison of experimental and calculated results showed that the proposed model adequately describes the process of formation of non-metallic inclusions in the steel under consideration and can be used for the development of industrial technology.

Numerical Investigation on Anti-Explosion Performance of Non-Metallic Annular Protective Structures.

Explosive shock wave protection is an important issue that urgently needs to be solved in the current military and public security safety fields. Non-metallic protective structures have the characteristics of being lightweight and having low secondary damage, making them an important research object in the field of equivalent protection. In this paper, the numerical simulation was performed to investigate the dynamic mechanical response of non-metallic annular protective structures under the internal blast, which were made by the continuous winding of PE fibers. The impact of various charges, the number of fiber layers, and polyurethane foam on the damage to protective structures was analyzed. The numerical results showed that 120 PE fiber layers could protect 50 g TNT equivalent explosives. However, solely increasing the thickness of fiber layers cannot effectively enhance the protection efficiency. By adding polyurethane foam in the inner layer, the stress acting on the fiber could be effectively reduced. A 30 mm thick polyurethane layer can reduce the equivalent stress of the fiber layer by 41.6%. This paper can provide some reference for the numerical simulations of non-metallic explosion protection structures.

Rigid but nonmetallic cranioplasty after pterional craniotomy: Technical note.

Background: Given the popularity of pterional craniotomy, numerous modifications have been made to prevent postoperative deformities. With the advent of titanium plates, fixation has become both simple and excellent. However, titanium plates can cause skin problems, infection, or cause skull growth to fail. Methods: To develop a simple, cost-effective, and esthetically satisfactory fixation method, without the use of non-metallic materials, six young and older patients underwent pterional craniotomy. CranioFix Absorbable clamps were used to fix the bone flap in the frontal and temporal regions such that the frontal part was in close contact with the skull. After fixation, the bone chips and bone dust were placed in the bone gap and fixed with fibrin glue. We measured the computed tomography values of the reconstructed area and thickness of the temporal profiles postoperatively over time. Results: Bone fusion was achieved in all patients by 1 year after surgery. Both the thickness of the temporalis muscle and the thickness of the temporal profile had changed within 2 mm as compared with the preoperative state. Conclusion: Our simple craniotomy technique, gentle tissue handling, and osteoplastic cranioplasty yielded satisfactory esthetic results and rigidness in pterional craniotomy.

Sodium alginate/Hydroxyapatite/nanocellulose composites: Synthesis and Potentials for bone tissue engineering.

Sodium alginate/hydroxyapatite/Nano cellulose (SA/HA/NC) nanocomposite films that possess good biocompatibility for bone tissue engineering are prepared by a simple solution casting. HA is one of the most frequently used bioceramic materials to achieve a high biocompatibility. The bionanocomposite films are analysed by XRD, SEM, EDAX and FTIR studies. XRD confirms the existence of fillers in the polymer. FTIR spectrum shows the different functional modes in the bionanocomposite films. The morphology of fillers and bionanocomposite films are obtained through SEM. The inclusion of NC with different concentrations into the biopolymer film improves the tensile strength. As a result, the loading of 5 wt % of NC and 10 wt% of HA in the SA polymer shows high tensile strength when compared to the pure SA, SA filled with 10 wt% of HA and SA loaded with 10 wt% of HA and inclusion of NC (0.5 and 2.5 wt%). The tensile strength (TS) of bionanocomposite film with 10 wt % of HA is increased by 17%. TS of bionanocomposite film with 0.5 and 2.5 wt% of NC is increased by 177 and 277%, whereas TS of bionanocomposite film loaded 5 wt% of NC is increased by 331%. The swelling, biodegradation and biomineralization tests suggest that this bionanocomposite films are hopeful biomaterials for bone tissue engineering.

Eco-friendly approach for enhancing the floatability of non-metallic components in waste printed circuit boards: Adding gutter oil during dry grinding.

Waste printed circuit boards (WPCBs) are an attractive secondary resource that is challenging to dispose of due to its complexity. Reverse flotation is an effective method to remove non-metallic particles (NMPs) to obtain metals from WPCBs. Nevertheless, the removal of NMPs is usually inadequate in the present flotation practice. Thus, to provide a clean approach to improve the removal efficiency of NMPs, the method of adding gutter oil during dry grinding process was adopted to enhance the hydrophobic sites on the surface of NMPs to improve the floatability. The surface morphology of NMPs was analyzed by SEM, the results show that the rough morphology inhibited the adhesion of bubbles, while water occupied the cracks and pores, making it challenging for collector adsorption, which result in unstable particle-bubble adhesion. The results of FTIR indicate that both NMPs and gutter oil have -CH3, -CH2, -C = O, -C-O functional groups, which promotes the adsorption of gutter oil on the surface of NMPs. The contact angle (CA) results show that the adsorption of gutter oil on the particle surface is conducive to the formation of enhanced CA. Furthermore, the flotation enhancement effect was verified by flotation kinetic experiments. The accumulated floats yield of NMPs conditioned by gutter oil during grinding is increased from 67.05% (NMPs without conditioning) to 95.02%, and the resin recovery is increased by 31.10%. It is demonstrated that dry grinding with gutter oil can strengthen the floatability of NMPs, which provides a potential approach to increase the flotation efficiency of WPCBs.

Recent Advances in Aqueous Non-Metallic Ion Batteries with Organic Electrodes.

Aqueous non-metallic ion batteries have attracted much attention in recent years owing to their fast kinetics, long cycle life, and low manufacture cost. Organic compounds with flexible structural designability are promising electrode materials for aqueous non-metallic ion batteries. In this review, the recent progress of organic electrode materials is systematically summarized for aqueous non-metallic ion batteries with the focus on the interaction between non-metallic ion charge carriers and organic electrode host materials. Both the cations (proton, ammonium ion, and methyl viologen ions) and anions (chloridion, sulfate ion, perchlorate ion, trifluoromethanesulfonate and trifluoromethanesulfonimide ion) storage are discussed. Moreover, the design strategies toward improving the comprehensive performance of organic electrode materials in aqueous non-metallic ion batteries will be summarized. More organic electrode materials with new reaction mechanisms need to be explored to meet the diverse demands of aqueous non-metallic ion batteries with different charge carriers in the future. This review provides insights into developing high-performance organic electrodes for aqueous non-metallic ion batteries.

The Development of Environmentally Sustainable Poly(vinyl chloride) Composite from Waste Non-Metallic Printed Circuit Board with Interfacial Agents.

The recycling of non-metallic printed circuit boards (NMPCB) as a filler in poly(vinyl chloride) (PVC) composite would help to encourage the use of waste NMPCB, thus, reducing some environmental concerns with regard to e-waste. The objective of this study was to comprehensively evaluate the effect of different interfacial agents, namely polypropylene grafted maleic anhydride (PP-g-MAH) and ϒ-aminopropyltriethoxy silane (ATPS) on the morphology and properties of PVC/NMPCB composites. A PVC/NMPCB composite was prepared by melt compounding with varying amounts of NMPCB ranging between 10, 20 and 30 wt.%. Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) analysis revealed the interactions between PVC and NMPCB when using both PP-g-MAH and ATPS interfacial agent. The properties and morphology of PVC/NMPCB composites were significantly dependent on the interfacial agent treated on the NMPCB surface. The phase morphology and mechanical properties of PVC/NMPCB composites (30 wt.% of NMPCB) were improved and the result also indicated that the higher compatibility of composites with ATPS as an interfacial agent led to our obtaining the maximum Young's modulus of 484 MPa. The dynamic mechanical analysis revealed the interaction at the interface, with the Tg shifting to a lower temperature in the presence of PP-g-MAH and strong interfacial adhesion noted with the improved Tg in the presence of the ATPS interfacial agent. Further evidence of the improved interaction was observed with the increment in density in the presence of ATPS when compared with PP-g-MAH in PVC/NMPCB composite. Hence, of the two interfacial agents, ATPS showed itself to be more effective when employed as an interfacial agent for NMPCB in PVC composite for industry.

Improved Tensile and Bond Properties through Novel Rod Constructions Based on the Braiding Technique for Non-Metallic Concrete Reinforcements.

Textile reinforcements have established themselves as a convincing alternative to conventional steel reinforcements in the building industry. In contrast to ribbed steel bars that ensure a stable mechanical interlock with concrete (form fit), the bonding force of smooth carbon rovings has so far been transmitted primarily by an adhesive bonding with the concrete matrix (material fit). However, this material fit does not enable the efficient use of the mechanical load capacity of the textile reinforcement. Solutions involving surface-profiled rods promise significant improvements in the bonding behavior by creating an additional mechanical interlock with the concrete matrix. An initial analysis was carried out to determine the effect of a braided rod geometry on the bonding behavior. For this purpose, novel braided rods with defined surface profiling consisting of several carbon filament yarns were developed and characterized in their tensile and bond properties. Further fundamental examinations to determine the influence of the impregnation as well as the application of a pre-tension during its consolidation in order to minimize the rod elongation under load were carried out. The investigations showed a high potential of the impregnated surface-profiled braided rods for a highly efficient application in concrete reinforcements. Hereby, a complete impregnation of the rod with a stiff polymer improved the tensile and bonding properties significantly. Compared to unprofiled reinforcement structures, the specific bonding stress could be increased up to 500% due to the strong form-fit effect of the braided rods while maintaining the high tensile properties.

Research on Intelligent Identification and Grading of Nonmetallic Inclusions in Steels Based on Deep Learning.

Non-metallic inclusions are unavoidable defects in steel, and their type, quantity, size, and distribution have a great impact on the quality of steel. At present, non-metallic inclusions are mainly detected manually, which features high work intensity, low efficiency, proneness to misjudgment, and low consistency of results. In this paper, based on deep neural network algorithm, a small number of manually labeled, low-resolution metallographic images collected by optical microscopes are used as the dataset for intelligent boundary extraction, classification, and rating of non-metallic inclusions. The training datasets are cropped into those containing only a single non-metallic inclusion to reduce the interference of background information and improve the accuracy. To deal with the unbalanced distribution of each category of inclusions, the reweighting cross entropy loss and focal loss are respectively used as the category prediction loss and boundary prediction loss of the DeepLabv3+ semantic segmentation model. Finally, the length and width of the minimum enclosing rectangle of the segmented inclusions are measured to calculate the grade of inclusions. The resulting accuracy is 90.34% in segmentation and 90.35% in classification. As is verified, the model-based rating results are consistent with those of manual labeling. For a single sample, the detection time is reduced from 30 min to 15 s, significantly improving the detection efficiency.

Hazardous elements in urban cemeteries and possible architectural design solutions for a more sustainable environment.

The general objective of this study is to identify the presence of hazardous elements in the soils of five urban cemeteries in the city of Passo Fundo, in southern Brazil, and to design solutions (architecturally) for future cemeteries to be more sustainable by mitigating toxicological risks to the population residing in the area. A total of 250 soil samples were obtained from points within the cemeteries and in areas surrounding the two oldest cemeteries at a distance of up to 400 m. Twelve architects who design cemeteries primarily focused on sustainability were interviewed, and presented their suggestions for sustainable urban cemetery design. The Building Information Modeling (BIM) computer modeling system was utilized to present a visual representation of suggested architectural features by these architects. The concentration of Pb in the vicinity of cemeteries deserves special attention, as concentrations of this neurotoxin exceed the federal limits set by Brazil. Soil Pb values were found to exceed the limit of 72 mg kg-1 up to a distance of 400 m from the walls of cemeteries A and B, indicating the presence of a danger to human health even at greater distances. This manuscript highlights construction features that enable future burial structures to adequately mitigate the very real problem of contaminants entering the environment from current cemetery design. Two-thirds of the technicians interviewed for this manuscript, each of whom specialize in Brazilian cemetery design, highlighted the importance of revitalizing urban vegetation both when constructing and revitalizing urban vertical cemeteries.

Construction of Z scheme S-g-C3N4/Bi5O7I photocatalysts for enhanced photocatalytic removal of Hg0 and carrier separation.

Photocatalysis has demonstrated the potential to solve challenges in various practical application fields such as energy and environmental science due to its environmental friendliness. However, the photocatalytic activity is mainly affected by the weak absorption of visible light and the low separation efficiency of photogenerated carriers. Herein, an S-doped g-C3N4/Bi5O7I heterojunction was designed by the calcination method. It was found that S doping not only reduces the band gap of g-C3N4, which raises the optical absorption boundary of g-C3N4 from 465 nm to 550 nm. At the same time, the introduction of S elements leads to new doping energy levels, which can act as photogenerated electron trapping centers and thus inhibit the complexation of photogenerated carriers. Second, the construction of the heterojunction greatly facilitates the transport of carriers and the separation of electrons and holes driven by the built-in electric field. Finally, the abundant oxygen vacancies in the system result in defective energy levels that not only promote the activation of molecular oxygen, but also act as photogenerated electron traps, which further boost the separation of electron-hole pairs. Benefiting from the optimized performance, the photocatalytic reaction rates of S-doped g-C3N4/Bi5O7I are 5.2 and 2.1 times higher than those of g-C3N4 and Bi5O7I, respectively. This work provides a viable idea for the potential development of non-metal doping combined with heterojunction photocatalytic systems.

Rice husk biochar mediated red phosphorus for photocatalysis and photothermal removal of E. coli.

The current photocatalytic bactericidal materials in the field of food pathogen control are usually consisted of metals that always suffering from poor stability and possible secondary pollution. Besides, the requirement for high energy excitation also inspires the enthusiasm on exploring non-metallic catalysts. Herein, the non-metallic composite of rice shell biochar loaded with red phosphorus (B@RP) was developed for photocatalysis and photothermal removal of bacteria. The B@RP showed effective photocatalysis performance to stimulate the generation of OH and O2- free radicals for the elimination of Escherichia coli (E. coli). At the same time, the photothermal effect of B@RP can also increase the permeability of cell membrane, which is conducive to free radicals entering the cell interior. Therefore, the non-metallic composite could achieve complete removal of E. coli within 2 h under illumination. Meanwhile, B@RP had excellent stability and the sterilization efficiency maintained 100% after 9 cycles. Hence, B@RP is expected to be a harmless and efficient bactericidal material for food industry.