Synthesis and characterization of pure cubic zirconium oxide nanocrystals by decomposition of bis-aqua, tris-acetylacetonato zirconium(IV) nitrate as new precursor complex

High Oxidation Desulfurization of Fuels Catalyzed by Vanadium-Substituted Phosphomolybdate@Polyaniline@Chitosan as an Inorganic-Organic Hybrid Nanocatalyst

From the environmental protection and human health perspectives, the design and synthesis of efficient and reusable oxidative desulfurization nanocatalysts has always been sought after by scientists and industries. In this regard, a new heterogeneous nanocatalyst (V-SPM@PANI@CH) was synthesized by immobilizing Keggin-type vanadium-substituted phosphomolybdate ([PVMo₁₁O₃₉]^4-) (named V-SPM) clusters on the surface of polyaniline (PANI) and chitosan (CH) polymers. The features of the assembled nanocatalyst were detected by Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy techniques in detail. The XRD studies indicated that the average crystallite size of V-SPM@PANI@CH was estimated to be about 36 nm. The catalytic performance of V-SPM@PANI@CH was investigated in the extractive and catalytic oxidation desulfurization (ECOD) procedure of real and thiophenic model gasoline by H₂O₂/AcOH (volume proportion of 2:1) as an oxidizing system. The optimal desulfurization conditions for ECOD reactions were as follows: 50 mL of model/real gasoline, 0.1 g of V-SPM@PANI@CH, reaction time of 60 min, and reaction temperature of 35 °C. Under the experimental conditions outlined above and the designed ECOD system, the content of sulfur in real gasoline could decline from 0.4985 to 0.0193 wt %, which corresponds to an efficiency of 96%. Moreover, the removal percentage of aromatic hydrocarbons, including thiophene (Th), benzothiophene (BT), and di-benzothiophene (DBT) as model fuels decreases in the order of DBT ≥ BT > Th under identical operating conditions. High catalytic activity was maintained with only a slight loss during five cycles. This work offers the ECOD system (V-SPM@PANI@CH/AcOH/H₂O₂) for the desulfurization of liquid fuels, which had a great repercussion on the ECOD efficiency.

Construction of an S-scheme TiOF2/HTiOF3 heterostructures with abundant OVs and OH groups: Performance, kinetics and mechanism insight

Developing efficient photocatalysts is of crucial significance for the development of photocatalysis techniques. In this work, an S-scheme alkaline-washed TiOF₂/HTiOF₃(OHTOF) heterostructures with abundant Oxygen vacancies (Ovs) and OH groups was successfully constructed and used to remedy antibiotic wastewater under simulated sunlight. The generation of HTiOF₃ was induced by g-C₃N₄ regulation. The results displayed that OHTOF15 composite possessed the best photocatalytic performance, which could degrade 94.2% tetracyclinehydrochloride (TCH) at a rate speed constant of 1.077 min^-1 in 2.5 h. The after-alkali-washing process increased the concentration of OH groups and Ovs defects, and greatly enlarged the surface area. The abundant Ovs and OH groups were conducive to the formation of free radicals' and the transport of charge carriers. Compared with the pristine TiOF₂, the absorption sidebands of OHTOF series were greatly red-shifted, which indicated that the increase of OH groups and the etching of the morphology of OHTOF further enhanced its visible-light harvesting ability. Furthermore, the metal cycle of the variable state of Ti⁴⁺/Ti³⁺ in OHTOF15 compensated for the charge balance and promoted the efficient separation of the carriers. Additionally, the apparent quantum efficiency (AQE) of the TCH photodegradation system based on Chemical Oxygen Demand (COD) removal efficiency was calculated to be 0.32%. It was confirmed that the electron transport path in TiOF₂/HTiOF₃ nanocomposites system followed the S-scheme type, which increased the charge carriers' separation rate and maintained a strong redox capacity. This work could provide some enlightenment for the construction of the semiconducting heterojunction and controllable surface defects engineering.

Remarkably efficient charge transfer through a double heterojunction mechanism by a CdS-SnS-SnS2/rGO composite with excellent photocatalytic performance under visible light

In this work, a novel CdS-SnS-SnS₂/rGO photocatalyst with two tin valence states (Ⅱ and IV) was successfully synthesized by a one-pot solvothermal method. For comparison, CdS-SnS₂/rGO (GCS2) with tin in only the IV valence state was made by the same method. Based on a series of characterizations, CdS, SnS and SnS₂ were shown to be successfully loaded onto the rGO surface. The introduction of rGO may increase charge carrier separation. The degradation efficiency increased gradually with increasing rGO loading content, and the optimum photocatalytic activity was observed at 6.0 wt% rGO loading content (GCS1), which achieved the efficient removal (84.46%) of ibuprofen over 60 min. Compared with GCS2, the CdS-SnS-SnS₂/rGO composite exhibited significantly improved photocatalytic performance, which can be ascribed to the formation of a double heterostructure. rGO worked as a transfer mediator to transfer electrons from the conduction band (CB) of SnS to the CB of SnS₂ at the heterointerface, which then flowed to the CB of CdS because of another heterojunction, further enhancing the separation efficiency of photogenerated carriers. Therefore, this study highlights a novel double heterojunction system with a facial preparation method, visible light response and good recyclability, which is beneficial for environmental remediation.

Magnetic, Pseudocapacitive, and H2O2-Electrosensing Properties of Self-Assembled Superparamagnetic Co0.3Zn0.7Fe2O4 with Enhanced Saturation Magnetization

The present work explores the structural, microstructural, optical, magnetic, and hyperfine properties of Co0.3Zn0.7Fe2O4 microspheres, which have been synthesized by a novel template-free solvothermal method. Powder X-ray diffraction, electron microscopic, and Fourier transform infrared spectroscopic techniques were employed to thoroughly investigate the structural and microstructural properties of Co0.3Zn0.7Fe2O4 microspheres. The results revealed that the microspheres (average diameter ∼121 nm) have been formed by self-assembly of nanoparticles with an average particle size of ∼12 nm. UV-vis diffuse reflectance spectroscopic and photoluminescence studies have been performed to study the optical properties of the sample. The studies indicate that Co0.3Zn0.7Fe2O4 microspheres exhibit a lower band gap value and enhanced PL intensity compared to their nanoparticle counterpart. The outcomes of dc magnetic measurement and Mössbauer spectroscopic study confirm that the sample is ferrimagnetic in nature. The values of saturation magnetization are 76 and 116 emu g-1 at 300 and 5 K, respectively, which are substantially larger than its nanosized counterpart. The infield Mössbauer spectroscopic study and Rietveld analysis of the PXRD pattern reveal that Fe3+ ions have migrated from [B] to (A) sites resulting in the cation distribution: (Zn2+ 0.46Fe3+ 0.54)A[Zn2+ 0.24Co2+ 0.3Fe3+ 1.46]BO4. Comparison of electrochemical performance of the Co0.3Zn0.7Fe2O4 microspheres to that of the Co0.3Zn0.7Fe2O4 nanoparticles reveals that the former displays greater specific capacitance (149.13 F g-1) than the latter (80.06 F g-1) due to its self-assembled porous structure. Moreover, it was found that Co0.3Zn0.7Fe2O4 microspheres possess a better electrochemical response toward H2O2 sensing than Co0.3Zn0.7Fe2O4 nanoparticles in a wide linear range.

Interface and defect engineer of titanium dioxide supported palladium or platinum for tuning the activity and selectivity of electrocatalytic nitrogen reduction reaction

Electrocatalytic N₂ reduction reaction (NRR) under ambient condition is considered as an alternative and environmental-friendly technique to substitute the conventional process of Haber-Bosch for NH₃ production. However, there are still hurdles for researchers to control the balance between N₂ activation and competitive hydrogen evolution reaction (HER) to obtain high selectivity of NRR. Herein, we synthesized Pt/TiO₂ and Pd/TiO₂ hybrids by using laser ablation in liquid (LAL) technology combined with hydrothermal treatment and compared their activity and selectivity of N₂ reduction. The results concluded that Pt/TiO₂ exhibited a higher NH₃ yield rate whereas Pd/TiO₂ achieved a better FE for artificial N₂ fixation, confirming that enhanced activity surely needs more electrons and protons to participate in the reaction, but the limited protons and electrons furnishing could restrain HER activity and improve selectivity of NRR. Comparing with Pt/TiO₂, Pd/TiO₂ hybrids could serve as a superior catalyst for keeping a balance relationship between HER and NRR to realize excellent selectivity and high yield rate simultaneously in an alkaline solution. Overall, this work will provide a significant practice to rational design electrocatalysts for NRR at ambient conditions and Pd-based materials might open an electrocatalyst paradigm to solve the global energy and ecological crisis.

Synthesis and biological function of Nickel and Copper nanoparticles

Nickel and Copper nanoparticles were synthesized by simple chemical method and studied for antimicrobial activities. The size of synthesized Nickel and Copper nanoparticles was found to be 24.00 nm and 13.13 nm respectively. The XRD analysis reveals the crystal system of Nickel and Copper nanoparticles. Copper nanoparticles were found orthorhombic whereas the nickel nanoparticles were monoclinic. The antimicrobial activities of Nickel and Copper nanoparticles dispersed in DMSO was investigated. Comparative sensitivity test of these synthesized nanoparticles was carried out against three pathogenic micro-organisms (Gram negative bacteria), viz. Escherichia coli, Klebsiella pneumoniae and Pneumonia Typhus, using agar diffusion cup plate method. Copper and Nickel nanoparticles have shown appreciable sensitivity at 100 μg/ml against all test micro-organisms. Comparatively, Copper nanoparticles were found to exhibit higher zone of inhibition (ZOI) than Nickel nanoparticles.

Effect of ligand on particle size and morphology of nanostructures synthesized by thermal decomposition of coordination compounds

Thermal decomposition of organometallic and various coordination compounds are known as general method to synthesize a wide range of nanostructures including metals, metal oxides and sulfides. Herein, in order to coordinate metals and prepare suitable precursor - due to the efficient role of precursor on the particle size and morphology of products - appropriate ligands will be introduced.

Adopting the principles of collagen biomineralization for intrafibrillar infiltration of yttria-stabilized zirconia into three-dimensional collagen scaffolds

In this paper, we report a process for generating collagen-yttria-stabilized amorphous zirconia hybrid scaffolds by introducing acetylacetone-inhibited zirconia precursor nanodroplets into a poly(allylamine)-coated collagen matrix. This polyelectrolyte coating triggers intrafibrillar condensation of the precursors into amorphous zirconia, which is subsequently transformed into tetragonal yttria-stabilized zirconia after calcination. Our findings represent a new paradigm in the synthesis of non-naturally occurring collagen-based hybrid scaffolds under alcoholic mineralizing conditions.