Publications

Abstract With the use of traditional Haber‐Bosch N 2 fixation, a huge amount of CO 2 emission bring a huge burden to the environment. Electrochemical N 2 reduction provides an environmental‐friendly and sustainable alternative to NH 3 synthesis at ambient conditions. Herein, we report our recent experimental finding that Ag composited with TiO 2 can greatly improve the N 2 reduction reaction performance of TiO 2 toward ambient conversion. In 0.1 M Na 2 SO 4 (pH=7), such electrocatalyst achieves a large NH 3 yield rate of 14.88 μg h −1 mg −1 cat. with a Faradaic efficiency of 6.2 % at −0.70 V vs. reversible hydrogen electrode. Besides, it also demonstrates high electrochemical and structural stability for NH 3 generation.

The corrosion issue with acidic and alkaline water electrolyzers can be avoided by developing water oxidation catalysts performing efficiently under benign conditions. In this Letter, we report that a NiFe-borate layer can be generated on a NiFe-layered double hydroxide nanosheet array hydrothermally grown on carbon cloth via an in situ electrochemical surface derivation process in potassium borate (K-B_i) solution. The resulting 3D NiFe-LDH@NiFe-B_i nanoarray (NiFe-LDH@NiFe-B_i/CC) demonstrates high activity for water oxidation, demanding overpotentials of 444 and 363 mV to achieve 10 mA cm^-2 in 0.1 and 0.5 M K-B_i (pH: 9.2), respectively, rivaling the performances of most reported non-noble-metal catalysts in near-neutral media. Notably, this electrode also shows strong electrochemical durability with a high turnover frequency of 0.54 mol O₂ s^-1 at overpotential of 600 mV. All these features promise its use as an efficient earth-abundant catalyst material for water oxidation under eco-friendly conditions.

In this Letter, we report the development of hierarchical CoTe2 nanowire array on Ti mesh (CoTe2 NA/TM) via topotactical conversion from its Co(OH)F precursor through hydrothermal tellurization reaction. As a 3D oxygen evolution electrocatalyst, such CoTe2 NA/TM exhibits excellent catalytic activity with an overpotential of 340 mV to attain 50 mA cm–2 in 1.0 M KOH. Notably, it also exhibits high durability for 25 h.

Abstract The present investigation targets the physical, mechanical, and thermal characteristics of glass fabric‐reinforced vinyl ester/polyester hybrid laminates filled with ferrous, nickel, and tungsten micro‐particles. The metal‐fillers‐glass fabric reinforced vinyl ester/polyester hybrid composites was produced by distributing 1 wt% ferrous, nickel, and tungsten with an ultrasonication probe‐assisted wet layup method. Polyester resin reinforced with glass fabrics and tungsten fillers (PRGT) presents improved mechanical characteristics compared with other hybrid laminates, with tensile, compression, and flexural strength values of 157.89 MPa, 163.74 MPa, and 167.29 MPa, respectively. The fractographic microstructure of tensile fracture PRGT laminates exhibits that glass fibers pull out, microcracks, and lower gaps, because of stronger filler‐fabric‐matrix adhesion when compared with other hybrid laminates. The artificial neural network modeling was conducted to choose the best composite among the various manufactured composites. Statistical analysis was observed from the one‐way ANOVA technique, substantiating that the physical, mechanical, and thermal characteristics of metal fillers‐reinforced hybrid composites were statistically significant. Highlights Metal‐fillers‐glass fabric reinforced vinyl ester/polyester hybrid composites. Selection of the best composite from developed composites by ANN. Tungsten fillers are a useful material for reinforcement.

This work has developed a facile strategy to create magnetically separable, core‐shell structured composites consisting of a magnetic Ag nanowires (NWs)/Fe 3 O 4 cores and an outer mesoporous TiO 2 (mTiO 2 ) shell using a sol–gel process and subsequent hydrothermal treatment. Benefiting from the mesoporous anatase TiO 2 as well as the unique structures of the composite, the resulting Ag NWs/Fe 3 O 4 @mTiO 2 composite was employed as a catalyst for removal of the organic contaminants through a colorimetric photocatalytic degradation assay using methylene blue (MB) as a model contaminant. Moreover, the photocatalysts can be easily separated and recycled with an external magnetic field and possess prominent recoverability.

In this communication, we demonstrate that a nickel cobalt sulfide nanosheet film electrodeposited on a titanium mesh (Ni-Co-S/TM) exhibits high catalytic activity toward electrooxidation of glucose. As a nonenzymatic glucose sensor, this Ni-Co-S/TM catalyst electrode shows a wide linear response range of 0.001-3 mM, a low limit of detection of 0.12 μM with a signal-to-noise ratio of 3, a sensitivity of 3291.5 μA mM^-1 cm^-2, and a fast response time of less than 5 s. Moreover, it also demonstrates high selectivity, good reproducibility and long-term stability for glucose detection.

Water pollution is considered a perilous issue that requires an immediate solution. This is largely because of the strong correlation between the global population increase and the amount of waste produced (most notably food waste). This project prompts the conversion of food waste into useful materials that can be used with sodium alginate as a catalytic support for metal nanoparticles. Sodium alginate/banana peel (Alg/BP) beads were prepared simply using an eco-friendly method. The prepared materials were modified using nanostructured materials to enhance their characteristics. Alg/BP beads were employed as adsorbents for metals that were then treated with sodium borohydride to produce MNPs@Alg/BP. Different MNPs@Alg/BP (MNPs = Ag, Ni, Co, Fe, and Cu) were used as catalysts for reducing 4-nitrophenol (4-NP) by NaBH₄ to evaluate each catalyst performance in a model reaction. The results exhibited that Cu@Alg/BP was most efficient toward complete transformation of 4-NP. Therefore, Cu@Alg/BP was also used as a catalyst for the reduction of potassium ferricyanide, congo red, methyl orange (MO), and methylene blue. It was found that Cu@Alg/BP beads catalytically reduced up to 95-99% of above pollutants within a few minutes. Cu@Alg/BP beads were more selective in reducing MO among the pollutants. The catalytic activity of Cu@Alg/BP was examined by evaluating the impact of numerous parameters on MO reduction. The results are expected to provide a new strategy for the removal of inorganic and organic water contaminants based on efficient and low-cost catalysts.

Spiro-type molecules have been extensively explored as hole-transporting materials (HTMs) in perovskite solar cells (PSCs). However, a closer look at the rule of design of such molecules is missing, and a combined experimental and theoretical study is needed. In this work, three spiro-[cyclopenta[1,2-b:5,4-b′]dithiophene-4,9′-fluorene] (SDTF) derivatives decorated with triphenylamine have been designed and synthesized. The thermal and optoelectronic properties, single-crystal structures, and charge-transport properties have been extensively investigated to reveal the impact of the linkage position of triphenylamine groups by combining experimental and theoretical methods, and the results are consistent with each other. Moreover, transfer integrals and reorganization energies in these molecules are also calculated to predict hole mobility. Our comprehensive studies show that SDTF-2 with a suitable energy alignment, good hole injection/transportability, and high theoretical hole mobility can be employed for efficient perovskite solar cells, achieving a high power conversion efficiency of 19.3%. In addition, first-principle calculations reveal that the strong interactions between SDTF-2 and the perovskite surface can facilitate fast hole extraction. Our way of study has provided useful information as part of the Materials Genome Initiative. We hope our investigation will offer a reliable path to predict or find the potential of novel spiro-type HTMs to become the alternative choice of spiro-OMeTAD.

In order to prepare fiber-type nanohybrid composites for electrochemical and antimicrobial applications, polypyrrole was combined with carboxymethylcellulose and multiwalled carbon nanotubes (PPy/CMC/MWCNTS). These composite materials were synthesized using ultrasonication and in situ polymerization. By using analytical methods, the structure and morphology of the synthesized nanohybrid composite material were confirmed. Slurry of fiber-type PPY/CMC/MWCNT composites synthesized in ethanol was deposited as a thin-uniform layer with conductive nafion (5% ethanolic solution of nafion) binder. Based on electrochemical measurements in a phosphate buffer medium, Sb3+ ions have linear responses between 0.1 nM and 0.01 mM, which is known as linear dynamic range (LDR). A sensor’s sensitivity (22.4304 µAµM−1cm−2) is calculated using the LDR slope by considering the GCE surface area (0.0316 cm2). A signal-to-noise ratio of 3 is used to estimate the lower limit of detection which is equal to 96.82 ± 4.84 pM. Moreover, the antibacterial activity of the obtained polypyrrole/carboxymethylcellulose/MWCNT composite has also been evaluated “against Gram-positive bacteria B. subtilis along with S. aureus, as well as Gram-negative bacteria, P. aeruginosa along with Escherichia coli by utilizing” autoclave of agar media. In electrochemical analysis, the proposed Sb3+ cationic sensor exhibits appreciable reproducibility, response time, stability, and outstanding outcome in analysis of real samples. In the field of metal ion sensor, this reliable method might be prospective in the recent future.