Chemical Precipitation Method Research Articles

Rational design of multi-component Fe(OH)3/Ni-NiO heterostructures bifunctional catalyst for electrochemical water splitting

Exploring economic-efficient bifunctional catalysts is critical for the production of green hydrogen through water splitting. Herein, we fabricate a novel hybrid catalyst with three-phase heterojunction (Fe(OH)3/Ni-NiO) via a simple electrodeposition and chemical precipitation method. Benefiting from the desirable amorphous-crystal interfaces, the electronic structure of Ni, NiO and Fe(OH)3 is regulated, which will optimize the adsorption of H intermediates (H*) and also reduce the kinetic barrier for the hydrogen evolution reaction (HER). The optimal Fe(OH)3–3/Ni-NiO/CC shows superior bifunctional activity with low overpotentials of 66 mV for HER and 220 mV for OER at 10 mA cm−2 in alkaline solution, respectively, as well as remarkable durability over a period of 40 h. Besides, Fe(OH)3–3/Ni-NiO/CC requires 1.52 and 1.72 V to deliver 10 and 100 mA cm−2 and shows no obvious increase in current within 40 h toward overall water splitting. Experimental and theoretical results show that the HER process is promoted by the synergistic effect of electronic redistribution between Ni, NiO and Fe(OH)3 due to the construction of three phase crystalline-amorphous heterogeneous interface. Meanwhile, Fe(OH)3 and NiO appeared reconstruction, transforming into FeOOH and NiOOH during OER process, respectively. This work offers a simple synthesis method for designing bifunctional catalysts for water splitting.

Synergistic effect of ZnO/Ag2O@g-C3N4 based nanocomposites embedded in carrageenan matrix for dye degradation in water

This research achieved success by synthesizing innovative nanocomposite composed of zinc oxide (ZnO), graphitic carbon nitride (g-C3N4) and silver oxide (Ag2O) nanomaterials incorporated into a carrageenan matrix, thus creating an environmentally friendly and stable support structure. The synthesis process involved hydrothermal and chemical precipitation methods to create photocatalytic g-C3N4, ZnO, and Ag2O nanocomposites. The success is evident through the characterization results, which unveiled distinctive peaks corresponding to Zn–O (590-404 cm−1) and Ag–O (2072 cm−1) stretching in the Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses, conclusively confirming the successful synthesis of g-C3N4, ZnO, Ag2O, and their respective nanocomposites. Further validation through a scanning electron microscope coupled with an energy dispersive spectrometer (SEM-EDX) and elemental mapping affirmed the presence of Zn, O, Ag, C, and N. Additionally, transmission electron microscope (TEM) imaging unveiled the nanosheet morphology of g-C3N4, the nanorod structure of ZnO, and the spherical form of Ag2O nanomaterials. ZnO and Ag2O nanomaterials demonstrated a consistent 10–20 nm size range. To underscore their ability to harness visible light, the nanomaterials were excited at 380 nm, emitting visible light emission within the 400–450 nm range. The synthesized nanocomposites showcased outstanding adsorption and photocatalytic properties, achieving efficiency ranging from 80 % to 98 %, attributed to the synergistic interactions between the various components. These findings culminate in a confirmation of the research's success, validating the exceptional potential of these nanocomposites for various applications.

Correlation between positron annihilation lifetime and photoluminescence measurements for calcined Hydroxyapatite

Hydroxyapatite (HAp) Ca10(PO4)6(OH)2 is a compound that has stable chemical properties, composition, and an affinity for human bone. As a result, it can be used in odontology, cancer treatment, and orthopedic grafts to repair damaged bone. To produce calcined HAp at 600 °C with different pH values, a wet chemical precipitation method was employed. All synthesized HAp samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), photoluminescence (PL), Zeta potential, and positron annihilation lifetime spectroscopy (PALS). The XRD results revealed that all calcined HAp samples were formed in a hexagonal structure with a preferred (002) orientation at different pH values. The crystal size of the samples was determined using the Scherrer equation, which ranged from 16 to 25 nm. The SEM and TEM results showed that the morphology of the samples varied from nanorods to nanospheres and rice-like structures depending on the pH value of the sample. The PL measurements indicated that the blue and green emission peaks of HAp were due to defects (bulk, surface, and interface) in the samples, which created additional energy levels within the band gap. According to Zeta potential measurements, the charge carrier changed from a positive to negative value, ranging from 3.94 mV to − 2.95 mV. PALS was used to understand the relationship between the defects and the photoluminescence (PL) properties of HAp. Our results suggest that HAp nanoparticles have excellent potential for developing non-toxic biomedical and optical devices for phototherapy.

Luminescence and two-photon absorption assisted optical limiting properties of Ag-doped CdWO4 nanorods

The emerging demand for the fabrication of nonlinear optical materials with high limits of optical power is obvious in nonlinear optics due to their wide application in photonic devices. We report the linear and third-order nonlinear optical properties of Ag-doped CdWO4 nanorods and their dependence on Ag-doping concentration. CdWO4 nanorods with different Ag concentrations were synthesized by the chemical precipitation method and characterized by UV–Vis absorption, X-ray diffraction (XRD), Raman, Photoluminescence and its lifetime studies, X-ray Photoelectron spectroscopy and Transmission Electron Microscopy (TEM). The introduction of Ag ions has led to an increased redshift in the CdWO4 absorption spectra extended into longer wavelength bands, thus enhancing optical absorption within the visible range. The XRD pattern showed that the nanorods crystallized in a monoclinic wolframite structure. The incorporation of Ag in CdWO4 decreases the luminescence emission intensity due to surface quenching effect. Luminescence lifetime measurement reveals the longer decay lifetime for Ag-doped CdWO4 nanorods due to the reduction of density of defects and deep trap state. The nonlinear optical behaviour of the nanorods was investigated by an Open aperture Z-scan technique at 532 nm using pulsed wave Nd: YAG laser. Experimental results showed that reverse saturable absorption is responsible for the observed nonlinearity in the nanorods. The addition of Ag can significantly improve the nonlinear absorption coefficient and optical limiting effects of CdWO4 which can be used as a potential material in nonlinear optical devices.

Structural, optical, and morphological study of iron-nickel co-doped calcium hydroxide nanoparticles

Here we present a novel study of Calcium hydroxide and iron-nickel co-doped Calcium hydroxide nanoparticles. Calcium hydroxide (CH) and iron-nickel doped Calcium hydroxide (INCH) nanoparticles (NPs) were synthesized by a simple chemical precipitation method. XRD, FESEM-EDX, and FTIR were used to characterize the structural and morphological characteristics, while UV–Vis spectroscopy was used to study the optical alterations. The average crystallite size is estimated to be 63.75 nm and 66 nm for the CH and INCH nanoparticles, respectively. The FESEM analysis revealed that CHNPs form a hexagonal-like shape, whereas INCH NPs produce highly agglomerated dispersed particles. The UV–Vis spectroscopy revealed that the band gap changes with average crystallite size concurrently.

MnO2 nanosheets based catechol oxidase mimics for robust electrochemical sensor: Synthesis, mechanism and its application for ultrasensitive and selective detection of dopamine

Nanozymes have favorable activity and good stability, which are potential alternatives to natural enzymes and widely applied in biosensing. However, nanozymes based electrochemical sensors are fewer, because many nanozymes are not easy to form efficient electrocatalytic interface and experience interference from the possible oxidizable species. Herein, ultrathin MnO2 nanosheets (MnO2 NSs) were synthesized by reduction of KMnO4 in acidic environment by chemical precipitation method. The MnO2 NSs show excellent catechol oxidase mimicking activity. The steady-state kinetics of MnO2 NSs shows a higher Vmax of 3.441 µM s−1. Additionally, the catalytic mechanism is that in the presence of oxygen, catechol or its analogues are oxidized to quinone or quinoids, while oxygen is reduced to H2O. Afterwards, the possible mechanism of dopamine (DA) at MnO2 NSs-modified electrode is investigated. DA is first catalytically oxidized to dopamine quinone (DQ) by MnO2 NSs based catechol oxidase, which further undergoes irreversible electrochemical reduction to DA involving two protons and two electrons transfer during the process. On the basis of this, a selective and ultrasensitive amperometric detection of DA at 0.0 V (vs. SCE) was explored, which have two linear parts, 0.01–20 μM and 20–100 μM DA with the LOD of 4.1 nM (S/N = 3). Most importantly, the presence of oxidizable species including ascorbic acid, uric acid and cysteine may coexist with DA in biological systems do not exhibit any appreciable interference. The as-proposed method was applicable to detect DA in human serum samples with good satisfactory accuracy and recovery. This research casts prospect to apply nanozymes for electrochemical sensor with excellent analytical performance.

RGO modified α-Fe2O3–ZnFe2O4 heterojunction for improving sensing performance of α-Fe2O3 to triethylamine

In order to develop a sensitive, stable and cheap gas sensor for detection of triethylamine (TEA), the bimetal oxide of ZnFe2O4 with α-Fe2O3 heterojunctions with different proportions were synthesized and reduced graphene oxide (rGO) modified on heterojunctions by hydrothermal and chemical precipitation methods. The gas-sensing tests to TEA showed that the 6α-Fe2O3/ZnFe2O4-rGO (0.8 wt%) composite has highest response reaches 10.48–20 ppm TEA with a rapid response time of 29 s, an impressively low detection limit of 0.145 ppm and reliable stability within 32 days at operating temperature of 143 °C. Compared with reported before, it has higher response at lower operating temperature and lower concentration of test gas. The enhancing mechanism is attributed to the formation of semiconductor heterojunction, which makes the resistance of composite in air further increase and further decrease in TEA compared with α-Fe2O3 due to generating an additional electron depletion layer in the heterojunction interface, while rGO accelerates the electron transfer and provides more active sites for gas adsorption.

Nondestructive assessment of ZnO surge arrester operating condition based on time-domain dielectric characteristics

Given the expansion of the economy and the rise in electricity demand, it is imperative to ensure the safe operation of the power system. Zinc oxide (ZnO) surge arresters play a crucial role in preventing overvoltage that can potentially harm the grid. The study presents an innovative non-destructive assessment approach for evaluating the working condition of ZnO surge arresters based on time-domain dielectric characteristics, aiming to guarantee their safe functioning within the power grid. The proposed technique provides a platform for conducting aging experiments updates the procedure for preparing piezoresistors in ZnO surge arresters and examines their performance. Furthermore, a test bed was utilized to investigate polarization/depolarization currents. The findings revealed that the pressure-sensitive voltage exhibited a minimum value of 693.09 U1mA ·cm2 using the traditional solid-phase approach while employing the chemical precipitation method with a 2:1 alcohol-to-water volume ratio resulted in a maximum value of 1028.41 U1mA ·cm2. Under the traditional solid-phase method, the voltage gradient varied from 411.04 V·mm−1 to 585.12 V·mm−1 when using the chemical precipitation method with an alcohol-to-water volume ratio of 2:1 V ·mm−1. The condition of ZnO surge arresters can be evaluated non-destructively by the polarization/depolarisation charge differential, which increases with the average service life. In conclusion, this study provides methodological criteria for assessing ZnO surge arrester conditions to ensure safe operation of power grids.

Photocatalytic assisted chemical mechanical polishing for silicon carbide using developed ceria coated diamond core-shell abrasives

The practical application of current photocatalytic-assisted chemical mechanical polishing (PCMP) technology still faces some challenges and difficulties, such as complex preparation process of abrasives, chemical failure, and the use of toxic chemicals. Herein, novel CeO2-coated diamond core/shell structure abrasives were successfully synthesized using a chemical precipitation method and applied in SiC-PCMP. After coating CeO2 on the surface of the diamond, the materials removal rate (MRR) was 56% higher than that of the diamond abrasives. With ultraviolet (UV) irradiation, the MRR of CeO2/diamond abrasives (11.5nm/min) increased by about 195% compared with CeO2/diamond composite abrasives without UV. High surface quality (Ra: 0.4nm) of the SiC substrate was obtained under UV light irradiation. The materials removal mechanism of SiC-PCMP was proposed.

Novel magnetic separable BiOBr@Fe3O4 p-n heterostructure with highly efficient photocatalytic property toward organic pollutants

In this work, by considering good photocatalytic activity and p-type property but insufficient visible light absorbing property of BiOBr and excellent light absorption, n-type property of Fe3O4 that has poor photocatalytic property due to fast recombination of charge carriers having narrow bandgap, a solar light-active BiOBr@Fe3O4 p-n heterostructure was designed and synthesized for the first time using a versatile chemical precipitation method, combining the p-type BiOBr with the n-type Fe3O4. The developed photocatalyst underwent comprehensive investigation using various high-precision techniques. Its photocatalytic properties were assessed for the photodegradation of organic contaminants, such as Congo red (CR) and rhodamine B (Rh B), under solar light irradiation. The degree of mineralization of these pollutants by the BiOBr@Fe3O4 p-n heterostructure during photodegradation was also evaluated. Additionally, the photodegradation pathway was examined using LC-MS, and a possible mechanism were proposed. The findings reveal that the developed BiOBr@Fe3O4 p-n heterostructure exhibited exceptional photocatalytic performance, degrading 100 % and 81 % of Rh B and CR, respectively. Kinetic findings also indicate that the rate of photodegradations of the pollutants by the BiOBr@Fe3O4 heterostructure is approximately 7.2 and 3.4 times higher than that of pure Fe3O4 for the degradation of CR and Rh B, respectively. Besides, the developed heterojunction exhibited better photocatalytic performance than existing photocatalysts for photodegradation of CR and Rh B. The total organic carbon content (TOC) analysis further demonstrates the exceptional mineralization properties of the fabricated photocatalyst toward the pollutants. Therefore, the developed BiOBr@Fe3O4 p-n heterostructure shows promise in the treatment of these organic pollutants, contributing significantly to environmental remediation, particularly in photocatalysis.

Synthesis of flower-like ZnO nanoparticles for label-free point of care detection of carcinoembryonic antigen

In this work, flower-like ZnO nanoparticles (ZnONPs) were synthesized using zinc nitrate (Zn(NO3)2 6H2O) as a precursor with KOH. The morphology of the ZnONPs was controlled by varying the synthesis temperature at 50, 75 and 95°C. The morphology and structure of ZnONPs were characterized using scanning electron microscopy (SEM), and X-ray diffraction (XRD) and Brunauer-Emmett Teller (BET) analysis. ZnONPs were successfully synthesized by a simple chemical precipitation method. A synthesis temperature of 75°C produced the most suitable flower-like ZnONPs, which were combined with graphene nanoplatelets (GNPs) to develop a label-free electrochemical immunosensor for the detection of the colon cancer biomarker carcinoembryonic antigen (CEA) in human serum. Under optimum conditions, the developed immunosensor showed a linear range of 0.5 to 10 ng mL-1 with a limit of detection (LOD) of 0.44 ng mL-1. The label-free electrochemical immunosensor exhibited good selectivity, reproducibility, and repeatability, and recoveries were excellent. The immunosensor is used with a Near-Field Communication (NFC) potentiostat connected to a smartphone to facilitate POC cancer detection in low-resource locations.

Zinc oxide nanoflakes supported copper oxide nanosheets as a bifunctional electrocatalyst for OER and HER in an alkaline medium

Bifunctional electrocatalysts are the attractive research in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in the overall water-splitting reactions. The design and development of the cost-effective OER/HER bifunctional electrocatalysts with superior catalytic activity are still remaining as the big challenges. Herein, we have developed the CuO–ZnO nanocomposite as a bifunctional OER/HER electrocatalyst via simple chemical precipitation method. The nanocomposite was investigated for its crystalline structure, surface morphology and the functions of elements using XRD, FT-IR, SEM, TEM and XPS characterization techniques, respectively. The nanocomposite exhibited the excellent activity for the overall water-splitting in an alkaline medium. The CuO–ZnO nanocomposite showed the less onset potential of 1.4 and 0.15 V versus RHE in 1M KOH (Tafel slopes value of 0.180 and 0.400 V dec−1) for OER and HER, respectively. Hence, the as-prepared bifunctional electrocatalyst displayed the high stability for 10 h in the water electrolysis processes.

Visible light driven Z-scheme α-MnO2 (1D)/Bi7O9I3 (2D) heterojunction photocatalyst for efficient degradation of bisphenol A in water

Z-scheme heterojunctions are gaining attention for their outstanding photocatalytic performance in degrading organic pollutants due to improved charge separation efficiency. In view of this, the present study is focused on the synthesis of novel 3D α-MnO2/Bi7O9I3 (MB) nanocomposites heterojunctions of varying α-MnO2 contents via facile in-situ chemical precipitation method at room temperature. Under optimum conditions, MB4 (comprising 485 mg of α-MnO2) exhibited exceptional performance, achieving about 97.5% of bisphenol A (BPA) degradation in 80 mins with a degradation rate constant of 0.08354 min−1. Such superior performance is attributed to efficient interfacial integration and charge separation, validated through various characterization techniques. Further, MB4 heterojunction facilitated Z-scheme electron-hole pair transfer and exhibited an augmented specific surface area. The active species involved in the degradation of BPA were identified as •O2– and •OH in scavenging experiments and supported by findings based on EPR. Additionally, degradation pathways and plausible BPA intermediates have been proposed based on LC-MS/MS studies. Furthermore, with an impressive mineralization rate (89.5%), the toxicity study unveiled less harmful intermediates than the parent compound BPA. MB4 photocatalyst also exhibited commendable stability, as evidenced by its studies based on five reuse cycles with 92.9% efficiency. In essence, visible-light-driven Z-scheme α-MnO2/Bi7O9I3 heterojunction photocatalyst offered a simple and sustainable approach for producing environmentally friendly materials, underscoring its potential in the removal of BPA in water and wastewater treatment.

Optimization of Nanohydroxyapatite for Bone Tissue Engineering via Wet Chemical Precipitation Method

Optimization of Nanohydroxyapatite for Bone Tissue Engineering via Wet Chemical Precipitation Method

Silver Sulfide Anchored Anatase TiO2 Nanoparticles for Ultrafast Degradation of Selective Textile Dyes

AbstractThe surface modification of the TiO2 with selective narrow band gap of metal or metal sulfide is an attractive attention in recent years. Herein, tiny Ag2S nanoparticles are well anchored on the TiO2 surface by a cost‐effective chemical precipitation method for efficient photocatalytic activity. The decoration of Ag2S nanoparticles is clearly identified through electron microscopy studies. The UV‐Vis diffuse reflection spectra (DRS) revealed that TiO2/Ag2S composites absorbed broad spectrum in the visible region. The reduced band‐gap of 2.41 eV by anchored the Ag2S on TiO2 may boosted the photocatalytic activity. Particularly, incorporation of Ag2S nanoparticles increased charge separation efficiency, lowering recombination, and improving photocatalytic performance. Because of their unique structural and optical properties, TiO2/Ag2S composites have increased photocatalytic activity. The photocatalytic performance of the pristine Ag2S and Ag2S anchored TiO2 are Crystal violet (CV) and Methyl orange (MO) dye molecules under same experimental condition. As expected, the TiO2/Ag2S showed highest photocatalytic degradation efficiency than alone TiO2.

A Laboratory Investigation of the Adsorption Performance and Mechanism of Organics in Industrial Wastewater on mp-Zr(OH)4

We reported on the development of mesoporous zirconium hydroxide (mp-Zr(OH)4) sorbents with high capacity for adsorptive removal of organic pollutants from industrial wastewater. The sorbent was prepared by a one-step chemical precipitation method at room temperature. The adsorption capacity and removal efficiency for the chemical oxygen demand (COD) of the industrial wastewater were studied using an automatic adsorption measurement apparatus. The effects of different parameters (adsorbent dosage, adsorption time, regeneration times, adsorbate's molecular weight and adsorbate solubility), isotherm, thermodynamics, and kinetics were evaluated. By analyzing scanning electron microscopy (SEM) images and powder X-ray diffractograms (XRD) no obvious differences were observed for the sorbents before and after the adsorption of the organics, which indicated a structural stability of the sorbent. The specific surface area was reduced from 450 m2/g to 189 m2/g on adsorption, and after desorption of the organics the specific surface area was 350 m2/g. The adsorption of COD was analyzed in a Langmuir model that described the data better than the empirical Freundlich model. This finding points towards that the adsorption occurred as a monolayer on the mp-Zr(OH)4. The free energy of adsorption (ΔG) is in the range of −20 kJ/mol < ΔG < 0. Entropy changes are ΔS > 0. The kinetics of the adsorption of COD is better described with a Quasi-second-order dynamic model than with a Quasi-first-order dynamic model, which elucidates its primary reliance on porous adsorption surfaces and incorporation of chemical adsorption.

Advancing steel protection with Ceria@Talc-8-hydroxyquinoline modified Polyurethane coatings

This research delves into a hybrid framework involving the synthesis of composite particles combining ceria-modified talc (CeO2@Talc) through a chemical precipitation method. The hybrid particles were then loaded with 8-Hydroxyquinoline (8-HQ) to serve as a corrosion inhibitor. The resulting CeO2@Talc-8HQ hybrid particles were subsequently incorporated into a polyurethane (PU) matrix and deposited on steel substrate to investigate and assess their barrier properties. The synthesized particles and developed coatings were characterized in detail utilizing various techniques. The Brunauer–Emmett–Teller (BET) results showed a decrease in the specific surface area and pore volume of modified particles as compared to that of pristine talc. These results demonstrated the successful loading and modification of the particles. The thermal gravimetric analysis (TGA) results showed excellent thermal behavior with only 2 % weight loss beyond 900 °C of the modified CeO2@Talc particles. The potentiodynamic polarization results represented 76.28 % increase in the corrosion inhibition efficiency in the presence of the modified particles. When these modified hybrid particles were reinforced (1.wt%) into the PU matrix, they exhibited an impressive impedance modulus of 56.14 GΩ.cm2 at 0.01 Hz, outperforming blank PU coatings which showed 0.002 GΩ.cm2 after four weeks of immersion in a 3.5 wt% saline solution. The incorporation of modified particles into the PU matrix results in significant improvements in various observed parameters such as the lowest break point frequency, damage index, and intersection frequency of the bode plot. These positive outcomes indicated that the modified coatings efficiently blocked the micropores of the PU matrix, preventing the diffusion of electrolytes into the coatings. Overall, this study not only introduced a novel structural design for superior corrosion mitigation but also demonstrated promising potential of corrosion protection for industrial applications.

Non-enzymatic Glucose Sensor Based on Ni(OH)2/NF Materials Using Different Pulse Voltammetry Technique

Non-enzymatic glucose sensors have gained significant attention owing to their potential for accurate and cost-effective glucose detection. Nanomaterials play a pivotal role in enhancing performance of non-enzymatic glucose sensor. In this study, a novel non-enzymatic glucose sensor based on Ni(OH)2/NF (nickel hydroxide/nickel foam) materials was developed using different pulse voltammetry technique. Chemical precipitation methods have been used to grow Ni(OH)2 nanostructures directly on a nickel foam electrode. The characterization of the synthesized materials was performed through field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDX), and X-ray diffraction (XRD). The performance of the Ni(OH)2/NF-based glucose sensor was evaluated through electrochemical measurements. Nanoscale hive-like structures of Ni(OH)2 with a diameter ranging from 450 to 530 μm and a thickness of 20 nm were formed on the NF surface. The sensor exhibited good performance, displaying a high sensitivity of 8.42mA.mM-1.cm-2 with a low detection limit of 0.84 μM. These results position the synthesized electrode as a promising contender for non-enzymatic electrochemical glucose sensors.

Semi‐aromatic polyamide containing ether bond/hydroxyapatite composites: Preparation, structure and cytocompatibility

AbstractIn this work, semi‐aromatic polyamide containing ether bond (PAE10T) was synthesized through nucleophilic substitution reaction using 1, 10‐N, N′‐bis(4‐fuorobenzamide) decane (BFBD) and hydroquinone (HQ) as the raw materials. And then the composites hydroxyapatite/semi‐aromatic polyamide (40%HA‐PAE10T and 60%HA‐PAE10T) were prepared by chemical precipitation method. Mechanical, SEM, FT‐IR, XRD, DSC, TGA and bioactivity tests were performed to characterize the structure, morphology, thermal and mechanical properties of PAE10T and its composites. Mechanical tests revealed that the difference of HA in weight played an important role in mechanical performance of the composites. Furthermore, in comparison with PAE10T, the 60%HA‐PAE10T showed the highest enhancement in compressive strength (133 MPa) at 75.9%, and the 40%HA‐PAE10T given expression to the best increase in bending strengths (97 MPa) at about 18.4%. The 40%HA‐PAE10T and 60% HA‐PAE10T exhibited the mechanical performances closed to the cortical bone of human. After 28 days of dip in the phosphate buffer saline (PBS), PAE10T, and its composites showed satisfactory stability. The cell culture results showed all composites gad good cytocompatibility, cells attached on the materials well with excellent morphology. All the experimental results showed that the composites were expected to have a good application in the field of compact bone repair.

Improved piezo-photocatalysis for aquatic multi-pollutant removal via BiOBr/BaTiO3 heterojunction construction

Piezo-catalysis is a green and effective method for degrading rich and obstinate molecules in wastewater. Yet, the piezo-catalytic performance of frequently-used barium titanate (BTO) is still limited for practical applications, thus it is crucial to construct high-efficiency BTO-based catalysts. Herein, BiOBr/BTO heterojunction-based piezo-photocatalysts were successfully prepared using the chemical precipitation method, and an internal electric field was established via ultrasound to promote the separation of photogenerated electron-hole pairs through the synergistic effect of piezocatalysis and photocatalysis. Transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy were utilized to characterize the heterojunction. The degradation performance of Rhodamine B (RhB) by BiOBr/BTO is the best among various pollutants, giving a reaction rate constant up to 20.839 × 10−2 min−1, exceeding numerous previously reported catalysts. In addition, the piezo-photocatalytic reaction rate of BiOBr/BTO for Methyl Orange was 9.298 × 10−2 min−1, ≈ 3.3 times than those of pure BTO (2.806 × 10−2 min−1), and also ≈ 15.9 times and 3.3 times than those of single photocatalysis (0.585 × 10−2 min−1) or piezocatalysis (2.848 × 10−2 min−1). Importantly, the BiOBr/BTO heterojunction demonstrates excellent catalytic degradation performance for a broad range of pollutants (e.g., dyes and antibiotics) and their mixtures, as well as favorable cycling stability and repeatability with changed environmental conditions, displaying applicability in actual wastewater treatment. The possible degradation pathways of RhB were analyzed by liquid chromatography-mass spectrometry. The present work supplies a feasible strategy for the preparation of high-efficiency piezo-photocatalytic BTO-based heterojunctions, which can guide other composites for environmental remediation.