As-prepared Materials Research Articles

Dynamically regulated redox shuttling and nucleation of lithium polysulfides through the built-in ferroelectric field

Sulfur is highly desired for energy storage devices by virtue of its high theoretical specific capacity and natural abundance. Yet the lithium-sulfur battery becomes practically unstable due to the migration of lithium polysulfides (LiPSs), which is the major challenge for its widespread application. Here, we demonstrate that the polysulfide redox shuttling can be kinetically buffered, which relies on a rational design of ferroelectric/carbon interfaces in a silica-based host structure. In situ TEM observation shows that a robust sulfur host is constructed by spatially embedding ferroelectric BaTiO3 nanodots within both the shell and bulk of a yolk-shell microsphere. During the electrochemical cycling process, the as-prepared composite material functions as a LiPSs pocket. It facilitates the reversible LiPSs conversion, giving rise to long-term stabilization of lithium-sulfur battery. This is due to the synergetic effect of the built-in polarization electric field and abundant LiPSs nucleation sites at internal ferroelectric/carbon interfaces. Furthermore, we show that the nucleation and growth of Li2Sn can be regulated by the designed polarization electric field in the yolk-shell structure. This study further highlights the potential of physical field towards high-performance lithium-slfur batteries.

Highly efficient adsorption assisted photocatalytic decontamination of metronidazole by Co3O4 doped graphitic carbon nitrides

Since traditional wastewater treatment techniques only partially remove antibiotics like metronidazole (MTZ), the rising use of these drugs causes their entry into wastewater and receiving surface waterways. A flexible method that may effectively degrade such organic pollutants is adsorption assisted photocatalytic degradation. Herein, an easy mixing-and-heating procedure was used to synthesize visible light-induced g-C3N4/Co3O4 heterojunction photocatalysts. The structural properties and morphology of as-prepared materials were measured using characterization techniques such as FTIR, FSEM, and XRD analysis. The as-prepared catalyst has demonstrated a remarkable adoption and photocatalytic performance in degrading MTZ. It was found that 0.2 weight percent of Co3O4 was the optimum amount for achieving the best photocatalytic efficiency. A key factor in boosting photo-generated carrier separation is the synergistic interaction between g-C3N4 and Co3O4. The kinetics study of MTZ adsorption and degradation as well as factors effecting such as pH (2-10) and catalyst dosage process were investigated. The functional treatment method attained 78% degradation of MTZ under the following general conditions: pH = 6, g-C3N4/Co3O4 = 0.04 g/L, and reaction time = 200 min and MTZ concentration = 20 mg/L. A possible mechanism for the photocatalytic degradation was introduced, wherein O 2 • − was found to be the leading radical, whereas h + and H O • radicals contribute moderately to the degradation process. The research presents an appealing and environmentally friendly technique for the practical remediation of waste water carrying antibiotics.

Preparation and Properties of Elastic Mullite Fibrous Porous Materials with Excellent High-Temperature Resistance and Thermal Stability.

Mullite fiber felt is a promising material that may fulfill the demands of advanced flexible external thermal insulation blankets. However, research on the fabrication and performance of mullite fiber felt with high-temperature resistance and thermal stability is still lacking. In this work, mullite fibers were selected as raw materials for the fabrication of mullite fibrous porous materials with a three-dimensional net structure. Said materials' high-temperature resistance and thermal stability were investigated by assessing the effects of various heat treatment temperatures (1100 °C, 1300 °C, and 1500 °C) on the phase composition, microstructure, and performance of their products. When the heat treatment temperature was below 1300 °C, both the phase compositions and microstructures of products exhibited stability. The compressive rebound rate of the product before and after 1100 °C reached 92.9% and 84.5%, respectively. The backside temperature of the as-prepared products was 361.6 °C when tested at 1500 °C for 4000 s. The as-prepared mullite fibrous porous materials demonstrated excellent high-temperature resistance, thermal stability, thermal insulation performance, and compressive rebound capacity, thereby indicating the great potential of the as-prepared mullite fibrous porous materials in the form of mullite fiber felt within advanced flexible external thermal insulation blankets.

Nanostructured Carbon Fibres (NCF): Fabrication and Application in Supercapacitor Electrode.

A facile interconnected nanofibre electrode material derived from polybenzimidazol (PBI) was fabricated for a supercapacitor using a centrifugal spinning technique. The PBI solution in a mixture of dimethyl acetamide (DMA) and N, N-dimethylformamide (DMF) was electrospun to an interconnection of fine nanofibres. The as-prepared material was characterised by using various techniques, which include scanning electron microscopy (SEM), X-ray diffractometry (XRD), Raman, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) among others. The specific surface area of the interconnected NCF material was noticed to be around 49 m2 g-1. Electrochemical properties of the material prepared as a single-electrode are methodically studied by adopting cyclic voltammetry, electrochemical impedance spectroscopy, and constant-current charge-discharge techniques. A maximum specific capacitance of 78.4 F g-1 was observed for the electrode at a specific current of 0.5 A g-1 in a 2.5 M KNO3 solution. The electrode could also retain 96.7% of its initial capacitance after a 5000 charge-discharge cycles at 5 A g-1. The observed capacitance and good cycling stability of the electrode are supported by its specific surface area, pore volume, and conductivity. The results obtained for this material indicate its potential as suitable candidate electrode for supercapacitor application.

Synthesis of graphene-based nanocomposites with superior doxycycline removal efficiency and antimicrobial studies

Herein, we report the successful preparation of high-quality graphene (G) nanosheets up to the kg scale using an electrochemical technique using graphite rods from scrap dry cell batteries. The as-prepared graphene was then decorated in-stiu with niobium oxide (Nb2O5) and silver (Ag) nanoparticles to prepare Nb2O5@G and Ag@G nanocomposites. Powdered X-ray diffraction (p-XRD), Fourier-transform (FT-IR) infrared spectroscopy, UV–visible (UV–vis) spectroscopy, Raman spectroscopy, and scanning electron microscopy (SEM) were used to characterize the as-prepared nanocomposite material. This binary Nb2O5@G nanocomposite was subsequently used to degrade doxycycline antibiotic with an efficiency of 98.5 % in 120 min under visible light conditions. To determine the optimal scope of the as-prepared composite catalyst, degradation studies were performed at different pH values, photocatalyst doses and temperatures. Kinetics studies revealed that the processes followed pseudo-first-order kinetics. In addition, the as-synthesized graphene, Nb2O5@G and Ag@G nanocomposites were used for selective application against E. coli bacterial strains. Overall, Ag@G has shown good potential application prospects in the development of antibacterial materials in comparison with Nb2O5@G and pristine graphene. This study highlights the potential of as-prepared graphene-based nanocomposites for use in waste treatment and environmental bioremediation.

Highly stable reinforced nanostructure of silver-decorated on graphene oxide phytosynthesized through central composite design for antibacterial activity: Green and eco-friendly method

In this study, the simultaneous effects of reaction time, reaction temperature, and ratio of AgNO3 and Curcuma longa extract on the nanoparticle size in the silver nanoparticles@graphene oxide (Ag@GO) nanocomposite were thoroughly investigated via the central composite design model (CCD). The obtained results showed that all parameters played a crucial role in the change in the AgNPs size. Indeed, the synthesis conditions were determined to be 31.9 min, 60.22 °C, and volume ratio between AgNO3 and extract of 0.96 (mL/mL) according to the simulated model, while these were determined at 32 min, 60 °C, and 1.0 (mL/mL) of AgNO3:extract volume ratio in empirical experiments. Under these conditions, the average particle size of the AgNPs was determined to be 22.19 nm, which showed a negligible deviation as compared to the experimental result (23.47 nm). Furthermore, the characterization of the Ag@GO was also assessed, in which the AgNPs affirmed the presence of spherical shapes evenly distributed on the GO sheets through XPS spectra, XRD pattern, TEM, and AFM images results. In addition, the as-prepared material also shows a great antibacterial performance against both Escherichia coli and Staphylococcus aureus strains with the IC50 values of 2.70 and 2.86 μg/mL at the bacteria density of 108 CFU/mL. Besides, the stability of the Ag@GO material in the form of suspension after 3 months was also evaluated, in which insignificant changes in the morphological structure were observed as compared to the initial sample. The aforementioned results exerted the great potential of the as-prepared material as an antibacterial agent in medicinal applications.

Fe3O4@CNTs/WPU@CNF aerogel/Ag foam composites with a double-layer structure for absorption-dominated electromagnetic shielding performance

With the popularity of electronic devices, absorption-dominated multilayered electromagnetic shielding materials are increasingly attractive due to the effective decrease of second pollution compared to the traditional homogeneous electromagnetic shielding materials. However, the design of multilayered structure and strong interface adhesion of functional composite while keeping light weight and practical use is not readily to realize. Therefore, we propose herein a double-layer aerogel/foam composite electromagnetic shielding composite. The absorption layer is made by a nanocellulose (CNF)@waterborne polyurethane (WPU) aerogel, in which magnetic nano iron tetraoxide (Fe3O4) joined with carbon nanotubes (CNTs) to optimize the impedance matching. The reflection layer is a chemically silver-plated foam (AF) used to reflect the transmitted electromagnetic waves through its strong electrical conductivity, improving the overall ability of electromagnetic waves shielding and achieving enhanced electromagnetic shielding performance. The two layers are strongly combined by the adhesion of WPU without the use of adhesives. When the mass ratio of CNTs to Fe3O4 of 2:1 and the total mass fraction of 5 wt%, the EMI shielding efficiency of the composites reaches 62.81 dB in the X-band (8.2–12.4 GHz) at the thickness of 4 mm and the maximum value reaches a remarkable 76.63 dB at 1.17 GHz. The specific SE value of SSE/t reaches 1744.72 dB cm2 g−1. Thanks to the effect of AF layer, the average reflectivity is only 0.141, demonstrating an absorption-dominated shielding mechanism. In addition, the as-prepared composite material is remarkably flexible and deformation-resistant, with a density of only 0.0913 g cm−3 and can withstand approximately 85,000 times its own weight.

Thermal-Responsive Smart Windows with Passive Dimming and Thermal Energy Storage.

Chromogenic smart windows are one of the key components in improving the building energy efficiency. By simulation of the three-dimensional network of polymer hydrogels, thermal-responsive phase change materials (TRPCMs) are manufactured for energy-saving windows. For simulated polymer hydrogels, tetradecanol (TD) and a color changing dye (CCD) are filled in situ in poly(n-butyl isobutyrate) (PBB) networks. TRPCMs convert solar energy into thermal energy through a dark blue CCD. The TD phase change material (PCM) absorbs heat energy to become a transparent liquid. Simultaneously, the CCD changes from blue to colorless and transparent at around 45 °C. As a result, as-prepared TRPCMs transform from an opaque state at room temperature to a high-transparency state after melting (74.5%). TRPCMs also show a good thermal storage capacity, with a phase transition enthalpy exceeding 161.9 J g-1. As-prepared smart materials can simultaneously achieve photothermal conversion, thermal energy diffusion, latent heat storage, and resistance to liquid leakage at the phase interface between opaque and transparent states, providing more options for the design of energy-saving buildings.

Robust carbon dots-wrapped NiCo flower-like nanostructures for enhanced triiodide reduction

Replacing traditional counter electrodes (CEs) with Pt-free electrodes is one of the challenges for developing dye-sensitized solar cells (DSCs). Herein, we successfully synthesized carbon dots-wrapped NiCo flower-like nanostructure (NiCo/Cdots) and evaluated its application as CEs for DSCs. To characterize as-prepared materials, we conducted FESEM and TEM-EDS. Cyclic Voltammetry (CV), electrochemical Impedance Spectroscopy (EIS), Bode, and Tafel plots were then used to investigate the electrocatalytic properties of NiCo/Cdots CE. As a result, the as-prepared sample exhibited high electrocatalytic activity, low charger-transfer resistance, and large exchange current density. DSC based on NiCo/Cdots CE was assembled and showed a slightly lower PCE than Pt CE-based DSCs (8.27 and 8.52 %, respectively). However, it provided excellent stability during a long-term performance. These results indicated that CoNi/Cdots is a low-cost, easy-to-fabricate material with high potential as a CE of DSCs.

Enhanced Fenton-like catalysis via interfacial regulation of g-C3N4 for efficient aromatic organic pollutant degradation

For the efficient degradation of organic pollutants with the goal of reducing the water environment pollution, we employed an alkaline hydrothermal treatment on primeval g-C3N4 to synthesize a hydroxyl-grafted g-C3N4 (CN-0.5) material, from which we engineered a novel Fenton-like catalyst, known as Cu–CN-0.5. The introduction of numerous hydroxyl functional groups allowed the CN-0.5 substrate to stably fix active copper oxide particles through surface complexation, resulting in a low Cu leaching rate during a Cu–CN-0.5 Fenton-like process. A sequence of characterization techniques and theoretical calculations uncovered that interfacial complexation induced charge redistribution on the Cu–CN-0.5 surface. Specifically, some of the π electrons in the tris-s-triazine units were transferred to the copper oxide particles along the newly formed chemical bonds (C(π)-O-Cu), forming a π-deficient area on the tris-s-triazine plane near the complexation site. In a typical Cu–CN-0.5 Fenton-like process, a stable π-π interaction was established due to the favorable positive-negative match of electrostatic potential between the aromatic pollutants and π-deficient areas, leading to a significant improvement in Cu–CN-0.5's adsorption capacity for aromatic pollutants. Furthermore, pollutants also delivered electrons to the Cu–CN-0.5 Fenton-like system via a “through-space” approach, which suppressed the futile oxidation of H2O2 in reducing the high-valent Cu2+ and significantly improved the generation efficiency of •OH with high oxidative capacity. As expected, Cu–CN-0.5 not only exhibited an efficient Fenton degradation for several typical aromatic organic pollutants, but also demonstrated both a low metal leaching rate (0.12 mg/L) and a H2O2 utilization rate exceeding 80%. The distinctive Fenton degradation mechanism substantiated the potential of the as-prepared material for effective wastewater treatment applications.

Samarium-doped vanadium pentoxide nanorods anchored reduced graphene oxide nanocomposite as a bi-functional electrode material for supercapacitor and direct methanol oxidation fuel cell applications

In this work, we demonstrate a novel, facile synthesis of reduced graphene oxide nanosheets decorated samarium-doped vanadium pentoxide (RGO/Sm:V2O5) nanocomposite material and explore its application toward supercapacitor and direct methanol oxidation process. As-fabricated material and electrode were well-characterized to evaluate its surface morphology and functionalities. Results indicate a maximum capacitance value of 544 F/g for RGO/Sm:V2O5 modified electrode than the 2% Sm:V2O5 (346 F/g) and V2O5 (133 F/g) modified electrodes. In addition, an excellent Rct value (3.2 Ω) was achieved for the RGO-loaded Sm:V2O5 electrode than the 2% Sm:V2O5 electrode (4.7Ω). The RGO/Sm:V2O5 electrode also shows higher cyclic efficiency (98 %) at the 1000th cycle than the non-RGO loaded Sm:V2O5 electrodes. Furthermore, the fabricated electrodes were also examined for the direct methanol oxidation performances, and the results indicate a higher current density value of 181 mA/cm2 for RGO/Sm:V2O5 electrode than 2% Sm:V2O5 electrode (139 mA/cm2). The excellent electrochemical performance of the RGO/Sm: V2O5 electrode is mainly due to the presence of RGO nanosheet in the synthesized nanocomposite material. Therefore, as-prepared material can be applied as an excellent alternative electrode material for energy storage and conversion systems.

Sol-Gel Synthesis of Silica-Poly (Vinylpyrrolidone) Hybrids with Prooxidant Activity and Antibacterial Properties.

The present work deals with the sol-gel synthesis of silica-poly (vinylpyrrolidone) hybrid materials. The nanohybrids (Si-PVP) have been prepared using an acidic catalyst at ambient temperature. Tetramethyl ortosilane (TMOS) was used as a silica precursor. Poly (vinylpyrrolidone) (PVP) was introduced into the reaction mixture as a solution in ethanol with a concentration of 20%. The XRD established that the as-prepared material is amorphous. The IR and 29Si MAS NMR spectra proved the formation of a polymerized silica network as well as the hydrogen bonding interactions between the silica matrix and OH hydrogens of the silanol groups. The TEM showed spherical particle formation along with increased agglomeration tendency. The efficacy of SiO2/PVP nanoparticles as a potential antimicrobial agent against a wide range of bacteria was evaluated as bacteriostatic, using agar diffusion and spot tests. Combined effects of hybrid nanomaterial and antibiotics could significantly reduce the bactericidal concentrations of both the antibiotic and the particles, and they could also eliminate the antibiotic resistance of the pathogen. The registered prooxidant activity of the newly synthesized material was confirmative and explicatory for the antibacterial properties of the tested substance and its synergetic combination with antibiotics. The effect of new hybrid material on Crustacea Daphnia magna was also estimated as harmless under concentration of 0.1 mg/mL.

Fabrication and Characterization of Photocatalyst Pb3CdO7 for Degradation of Azure-A

Present work comprises of fabrication of the novel Pb3CdO7 ternary oxide composite from the corresponding precursors using a co-precipitation approach and calcined. The as-prepared material is then characterized by FTIR, FE-SEM, XPS, EDX, XRD, HR-TEM etc. analytical methods. Based on UV-Vis-NIR spectroscopy, the composite's direct energy band gap is determined to be 5.23 eV, which makes it an effective photocatalyst. The prepared photocatalyst is found to degrade Azure-A dye with an efficiency of up to 94.87%. Scavenger study suggests the participation of active free radicals O2•- (superoxide anion radical) as the responsible species in breakdown of the dye molecules. The operating parameters are controlled to maximize the photodegradation and a kinetic study is carried out. Used photocatalyst is recycled and is found to work at the same pace for up to five cycles.

Reduced internal stress of quasi-single crystalline Na4Fe3(PO4)2P2O7 electrode enhancing sodium-ion kinetics

A NASICON-type quasi-single crystalline Na4Fe3(PO4)2P2O7 (SC) cathode material was successfully synthesized via a freeze-drying method. The as-optimized SC sample displays both outstanding rate performance (107.9 and 88.5 mAhg−1 at 0.1C and 5C, respectively) and excellent cycling stability (88.1 % of capacity retention after 1000 cycles at 1C). Reduced sodium ion migration path of as-prepared SC cathode material effectively enhanced the kinetics of Na+ upon cycling. More importantly, the SC structure could suppress nearly 50 % of internal strain, prodigiously reducing the local stress accumulation accompanied by the inhomogeneous sodium concentration gradient during the charging/discharging processes. The smaller the stress accumulation, the more stable the crystal structure would be obtained, which maintained a more superb mechanical stability of the SC cathode material. At the same time, a high-spin state of Fe in the SC sample was confirmed by both of electron paramagnetic resonance and temperature-dependent magnetization susceptibility, indicating that the eg orbital occupation of Fe2+ could be regulated to optimize the bond strength between the reduction and oxidation processes. As a consequence, the band gap of SC material has decreased from 1.66 to 1.45 eV, and the electronic conductivity has increased from 6.0 to 32.4 μS/cm. It is believed that the SC cathode material could be a competitive candidate material for sodium ion batteries.

Hot injection synthesis of CuS decorated CdS and ZnS nanomaterials from metal thiosemicarbazone complexes as single source precursors: Application in the photocatalytic degradation of methylene blue

CdS and ZnS are considered excellent semiconductors for photocatalysis, but photocorrosion and low photocatalytic activity limit their practical application. In order to improve on their photocatalytic activities, Copper sulfide-decorated CdS and ZnS (CuS@CdS and CuS@ZnS) nanocomposites were synthesized from Cu(II), Zn(II) and Cd(II) complexes of 2–(phenyl(pyridin–2–yl)methylene)hydrazine–1–carbothioamide, as single source precursors using a facile hot injection method at 250 °C, employing olive oil as capping agent. The structure, morphology, and optical properties of the as-prepared nanocomposites were determined using various analytical techniques. The results of powder X-ray diffraction (p-XRD), energy dispersive X-ray spectroscopy (EDX) and elemental mapping showed the presence of CuS, CdS and ZnS in CuS@CdS and CuS@ZnS, confirming the formation of nanocomposites. Transmission Electron Microscopy (TEM) images show agglomeration of CuS nanoparticles on the surface of CdS and ZnS nanoparticles. Scanning electron microscopy (SEM) images of CuS@CdS and CuS@ZnS nanocomposites revealed an agglomerated flower-like structure with porous surface. The band gap energies of 2.84 eV and 3.12 eV for CuS@CdS and CuS@ZnS, respectively, obtained from Tauc plots, demonstrate that combining CuS with single CdS and ZnS has an effect on their optical properties which probably account for the improved photocatalytic responses. The photocatalytic performance of the as-prepared materials was evaluated using the photodegradation of methylene blue (MB) dye under UV light irradiation. Results show that the degradation efficiencies for CuS@CdS (57 %) and CuS@ZnS (65 %) nanocomposites exhibited higher photocatalytic activity compared to those of pure CuS (42.0 %), CdS (35.1 %) and ZnS (57 %), suggesting that thiosemicarbazone complexes can be used as precursors for the development of metal sulphide nanocomposites as useful photocatalysts for the degradation of organic pollutants.

Laser-induced nitrogen and phosphorus-doped spongy carbon with graphene wings derived from lignin for significantly enhanced capacitance deionization performance

Efficient capacitive deionization (CDI) technology puts forward higher requirements for electrode materials. However, the traditional process of preparing porous carbon (PC) electrodes by alkaline chemical activation is polluting and energy-consuming. In this work, the N/P co-doped biocarbon material (H-AL/APP) was prepared by using alkali lignin (AL) and ammonium polyphosphate (APP) as carbon precursors based on laser-induced carbonization and hydrothermal activation technology. The as-prepared carbon material shows a three-dimensional (3D) structure with a hierarchical porous structure, large specific surface area of 405.98 m2/g (SSA), excellent pore volume, and outstanding mesoporosity. Compared with commercial YP80 activated carbon, The H-AL/APP electrode exhibits a higher specific capacitance of 210F/g with excellent rate performance and cycle stability. When assembled for desalination, H-AL/APP shows the highest removal rate of 23 mg/g/min with an outstanding desalination capacity of 34.6 mg/g than those of YP80 activated carbon. Furthermore, reasonable cycle stability and reproducibility highlight their promising application prospects. In summary, this work provides a green, efficient, and economical method for preparing high-performance heteroatom-doped PCs for efficient CDI desalination.

Bandgap engineering of novel Cu-vanadate/g-C3N4 hierarchical nanoflowers for enhanced photodegradation and excellent biosensing capability

Copper vanadate and graphitic carbon nitride (g-C3N4) are pivotal materials in the realm of advanced materials science, owing to their distinctive optical and electronic conductive properties. In the context of environmental photocatalysis and biosensing applications, their synergistic combination holds significant promise. Copper vanadate, renowned for its optical and electronic properties, complements the unique architecture and optical conduction characteristics of g-C3N4. Together, these materials exhibit immense potential for driving advancements in environmental sustainability and diagnostic techniques. In this study, we report the synthesis of copper vanadate (Cu0.261V2O5) and its composite with graphitic carbon nitride. XRD confirms the synthesis of the novel phase, FESEM and TEM analysis reveals hierarchical nanoflowers and UV-Visible spectroscopy divulges the visible light activation of the synthesized material and aids in the calculation of the optical bandgap. Interfacial charge transfer was studied with the help of EIS and Mott-Schottky analysis was employed to reveal the semiconductor type (n or p type) and determine the band edges. The as-prepared material was tested for the photocatalytic removal of methylene blue (MB), followed by the study of reaction kinetics, cyclic stability and active radicals participating in the photocatalysis process. The synthesized heterojunction showed 100 % removal of MB within a tenure of 90 minutes. The results of the experiment revealed that Cu0.261V2O5 decorated with g-C3N4 displays 1.5 and 1.4 times better photocatalytic degradation capability than pure Cu0.261V2O5 and g-C3N4, respectively. Furthermore, the synthesized material was evaluated for electrochemical biosensing of ascorbic acid in PBS (pH 7) analyte using a 3-electrode system. Compared to the pure material, the heterojunctions drew 1.9 times more current and provided near unity correlation (R2). It is evident that Cu0.261V2O5 decorated with g-C3N4 can be implemented for commercial eco-remediation and electrochemical ascorbic acid sensing.

Development of Bio-Photoelectrochemical Hybrids for Solar Energy Conversion

Recent advancements in solar energy conversion have identified bio-photoelectrochemical hybrids as one of the most promising sustainable techniques. This study integrates BiVO4 and TiO2 semiconductors with photoautotrophic microorganisms (e.g., Algae) to enhance solar energy conversion. Thin films of these materials were prepared and characterized, revealing a relatively smooth surface for BiVO4 while structures for TiO2 thin films deposited as nanorods. Optical properties showed band gaps of ≤ 3.1 and 2.4 eV for TiO2 and BiVO4, respectively. The point of zero charge of materials was investigated, indicating that naturally occurring biofilm formation might not be favorable for as-prepared materials. To overcome this challenge, we aimed to use polyelectrolytes to enhance attachment of cells on the surface of semiconductor and in this regards we determined the biocompatibility of using this approach. Photoelectrochemical (PEC) measurements were conducted to evaluate solar energy conversion efficiency. This study offers insights into optimizing biosystem attachment, biofilm stability, and PEC performance of coupled semiconductors with photoautotrophic microorganisms as one photoelectrode in PEC cell, advancing sustainable solar energy conversion technologies.

Superhydrophobic/ superoleophilic polystyrene-based porous material with superelasticity for highly efficient and continuous oil/water separation in harsh environments

Three-dimensional separation materials with robust physical/chemical stability have great demand for effective and continuous separation of immiscible oil/water mixtures and water-in-oil emulsions, resulting from chemical leakages and discharge of industrial oily wastewaters. Herein, a superelastic polystyrene-based porous material with superhydrophobicity/superoleophilicity was designed and prepared by high internal phase emulsion polymerization to meet the aforementioned requirements. A flexible and hydrophobic aminopropyl terminated polydimethylsiloxane (NH2-PDMS-NH2) segment was introduced into the rigid styrene-divinylbenzene copolymer through 1, 4-conjugate addition reaction with trimethylolpropane triacrylate. The addition of NH2-PDMS-NH2 simultaneously improved the mechanical and hydrophobic properties of the porous material (the water contact angle from 141.2° to 152.2°). The material exhibited outstanding reversible compressibility (80% strain, even in liquid N2 environments) and superhydrophobic stability, even after being repeatedly compressed 100 times, water contact angle still remained above 150°. Meanwhile, the as-prepared material had outstanding hydrophobic stability in corrosive solutions (strong acidic, alkaline, high-salty, and even strong polar solvent), presence of mechanical interference, strong UV radiations, and high/low temperature environments. More importantly, the material could continuously and efficiently separate immiscible oil/water mixture and water-in-oil emulsions under the above conditions, showing huge potential for the large-scale remediation of complex oily wastewaters.

Simple and sensitive electrochemical sensing of amethopterin by using carbon nanobowl/cyclodextrin electrode

Resulted from the severe side effects, the development of inexpensive, simple and sensitive method for amethopterin (ATP, an antineoplastic drug) is very important but it still remains a challenge. In this work, low cost nanohybrid composed of carbon nanobowl (CNB) and β-cyclodextrins (β-CD) (CNB-CD) was prepared with a simple autopolymerization way and applied as electrode material to develop a novel electrochemical sensor of ATP. Scanning-/transmission-electron microscopy, Fourier transform infrared spectrum, photographic image and electrochemical technologies were utilized to characterize morphologies and structure of the as-prepared CNB and CNB-CD materials. On the basic of the coordination advantages from CNB (prominent electrical property and surface area) and β-CD (superior molecule-recognition and solubility capabilities), the CNB-CD nanohybrid modified electrode exhibits superior sensing performances toward ATP, and a low detection limit of 0.002 μM coupled with larger linearity of 0.005–12.0 μM are obtained. In addition, the as-prepared sensor offers desirable repeatability, stability, selectivity and practical application property, confirming that this proposal may have important applications in the determination of ATP.