Effective biosafe management strategies are used to decrease world crop damage produced by plant-parasitic nematodes. This study evaluated the efficiency of hydroxyapatite nanoparticles (n-HAP) and mycorrhizal fungi to control the Meloidogyne incognita infecting tomato plants. Application of n-HAP significantly increased the juveniles’ mortality (195.67%) and egg hatching inhibition percentage (80.71%) compared to the untreated control, in vitro. Mycorrhizal and/or n-HAP treatments increased the plant growth parameters (root and shoot length, dry weight, and leaf area) and reduced the negative consequence of nematode infection. This may be due to indirect mechanisms through increasing plant nutrient uptake efficiency and increasing the internal plant resistance against nematode infection. In dual-treated plants, phosphorus, nitrogen, and calcium content recorded the highest value in the nematode-infected plants. Whereas the dual inoculation significantly increased mineral contents in tomato plants compared with control, this may induce the strength of the cell wall of the epidermal layer and cortex and consequently increase the plant resistance against nematode infection. Our results revealed that the application of the plant resistance-stimulants enhanced the plant growth parameters and internal nutrient content and reduced the nematode’s criteria. Consequently, the internal plant resistance against nematode infection was induced.

The increasing global demand for petroleum oils has led to a significant increase in their cost and has led to the search for renewable alternative waste resources for biodiesel synthesis and production using novel environmentally sound and acceptable methods. In the current study, Kocuria flava lipase was immobilized on Fe₃O₄/cellulose nanocomposite; and used as a biocatalyst for the conversion of cooking oil wastes into biodiesel through the transesterification/esterification process. The characterization of Fe₃O₄/cellulose nanocomposite revealed several functional groups including carboxyl (C=O) and epoxy (C-O-C) groups that act as multipoint covalent binding sites between the lipase and the Fe₃O₄/cellulose nanocomposite and consequently increasing lipase immobility and stability. The immobilized lipase showed a high thermo-stability as it retained about 70% of its activity at 80 °C after 30 min. The kinetics of immobilized lipase revealed that the K_m and V_max values were 0.02 mM and 32.47 U/mg protein, respectively. Moreover, the immobilized lipase showed high stability and reusability for transesterification/esterification reactions for up to four cycles with a slight decline in the enzyme activity. Furthermore, the produced biodiesel characteristics were compatible with the standards, indicating that the biodiesel obtained is doable and may be utilized in our daily life as a diesel fuel.

In this work, Cu NPs were loaded at a fixed percentage (5 wt%) on 1D, (1D + 0D) and 0D ZnO nanostructures
to investigate the effect of the support morphology on the reduction of organic pollutants in water. The
synthesized materials were characterized by high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray
diffraction (XRD), N2 adsorption–desorption and X-ray photoelectron spectroscopy (XPS). The results
reveal that the loading of Cu NPs decreases the optical band gap, and a slight change in the crystallite
sizes increases the specific surface area value of the nanocomposites. The TEM images reveal that 1D
ZnO has an average width of 44.7 nm and an average length of 211 nm, while 0D ZnO has an average
diameter of 54.5 nm. The HR-TEM and XPS data confirm the loading of metallic Cu NPs on the surface
of the ZnO nanostructures. The pure ZnO and nanocomposites were tested for 4-nitrophenol (4-NP)
reduction in the presence of NaBH4 at room temperature. The obtained results show that pure ZnO
nanostructures have no catalytic performance, while the nanocomposites showed good catalytic
activities. The catalytic reduction efficiency of 4-NP was found to follow the order of Cu/0DZnO > Cu/
(1D + 0D)ZnO > Cu/1DZnO. The complete reduction of 4-NP has been observed to be achievable within
60 s using the Cu/0DZnO nanocomposite, with a kapp value of 8.42 min
1 and good recyclability of up
to five cycles. This nanocomposite was then applied in the reduction of organic dyes in water; it was
found that the reduction rate constants for the methylene blue, Congo red, and acriflavine hydrochloride
dyes were 1.4 min
1, 1.2 min
1, and 3.81 min
1, respectively. The high catalytic performance of this
nanocomposite may be due to the small particle size, high specific surface area, and the high dispersion
of Cu NPs on the surface of ZnO
 

Solar-driven hydrogen production via particulate photocatalysts is a sustainable and promising way for
overcoming the current energy crisis. In this work, CdS nanoparticles were synthesized via the
precipitation method and then decorated hydrothermally by NiMoO4 nanorods. The as-prepared CdSNiMoO4 nanocomposite showed an initial hydrogen generation rate (HGR) of 130 mmol h
1 under the
visible spectrum. This represents a 7-fold increase compared to that of pure CdS. Increasing the
hydrothermal treatment temperature of the nanocomposite above 90 C was found to have a negative
impact on the H2 production efficiency. The prepared composite was subjected to various
photoelectrochemical measurements for investigating the photoelectric properties and the proposed
mechanism. The results revealed that CdS and NiMoO4 semiconductors have well-established band
structures to form a type-II heterojunction. Thus, NiMoO4 works as an electron collector that captures
the photogenerated electrons from CdS, thereby promoting the separation of e
/h+ pairs. The
improvement in the catalytic performance could also be attributed to the increase in the active catalytic
sites of CdS-NiMoO4 (SBET ¼ 335.7 m2 g
1) compared with CdS (SBET ¼ 225.5 m2 g
1). Overall, this work
sheds light on using earth abundant NiMoO4 as an effective promoter in photocatalytic applications.
 

In this work, the production of dimethyl ether (DME) from methanol over natural kaolin clay modified
through impregnation with various percentages of H2SO4, WO3, or ZrO2 catalysts was investigated.
The prepared catalysts were characterized via X‑ray fluorescence, X‑ray diffraction, Fourier transform
infrared spectroscopy, scanning electron microscopy, and N2‑sorption analysis. The acidity of these
catalysts was determined through the dehydration of isopropyl alcohol and the chemisorption
of pyridine. The catalytic activity performance revealed that the addition of modifiers into kaolin
enhanced the latter’s activity toward DME production. In addition, the kaolin clay modified with
10 wt% ZrO2 exhibited excellent activity of 98% conversion with 100% selectivity at 275 °C. Moreover,
this catalyst could proceed the reaction for a long time (6 days) without any noticeable deactivation.
The remarkable improvement in the catalytic performance achievement was well correlated with the
acidity and the structure of the catalysts.
 

Liquid phase esterification of carboxylic acids with alcohols is an important organic synthesis process in the
petrochemical and fine chemical industries. These reactions required mineral acid catalysts, which are corrosive
and difficult to be separated from the reaction mixture. Therefore, the use of solid acid catalysts is economically
viable, reusable, and environmentally amicable. In this study, sugarcane bagasse ash (SCBA) was impregnated
with 1–10 wt% of sulfuric acid (H2SO4) or perchloric acid (HClO4) for the liquid-phase esterification of acetic
acid with n-amyl, benzyl, and n-butyl alcohols under various reaction conditions. The catalysts were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared (FTIR), N2 sorption, and scanning electron microscopy (SEM). Their acidities were measured through the dehydration of isopropyl alcohol and pyridine adsorption FTIR. The effects of the acid activation of SCBA on its texture properties (such as surface area and the nature of the surface functional groups), acidity, and catalytic activity were studied in detail. FTIR of the pre-saturated catalysts with pyridine reflected the presence of Brønsted and Lewis acid sites. The concentrations of the acid sites were improved by increasing the percentages of acid loading. All the catalysts showed high catalytic activity with 100% selectivity to ester formation. The catalyst pretreated with H2SO4 showed the higher ester yields compared to that of treated with HClO4. The optimum reaction conditions were a reaction time of 2 h, an alcohol-to-acid molar ratio of 1:3, and catalyst loading of 0.5 g. The highest yields of namyl acetate, benzyl acetate, and n-butyl acetate of 98, 90.8, and 70.5%, respectively, were achieved over the SCBA pretreated with 10 wt% H2SO4 catalyst. The high catalytic performance of this catalyst is due to the high surface acidity generated by the inductive effect of the S– –O bond.
 

A [ZrO2?BTB]C nanocomposite was synthesized and prepared as a thin film
using the sol–gel spin coating method. Different characterization techniques for
[ZrO2?BTB]C like FTIR, UV–Vis, and optical properties have been used. The
resulted XRD and SEM data have been employed to study interface composites.
The optimization was performed using DFT by DMol3 and CASTEP program.
The chemical structure was confirmed by spectroscopic and structural properties for [ZrO2?BTB]C. XRD results showed the same crystal structure. Combined
between experimental and TDD-DFT data, the average crystallite size and
composite interface are 12.36 nm and orthorhombic symmetry (a = 7.38(5);
b = 18.178(6); c = 26.10(3) A˚ and a = b = g = 90) with space group (P61) for
[ZrO2?BTB]C, respectively, while those computed by DFT are 2.897 eV and
2.492 eV for as-isolated crystals of [BTB]TF and [ZrO2?BTB]C, respectively. Both
[BTB]TF and [ZrO2?BTB]C thin films have direct allowed transitions. In addition, the optoelectrical parameters have been calculated for [BTB]TF and
[ZrO2?BTB]C films such as refractive index, extinction coefficient, dielectric
constant, and optical conductivity. The simulated values obtained by CATSTEP
for the optical parameters of [ZrO2?BTB]C are in good agreement with the
experimental values. PL technique analyses indicated two emission peaks
appeared at 357 nm, and 497 nm for [ZrO2?BTB]C, whereas three emission peaks
appeared at 335 nm, 383 nm, and 477 nm for [BTB]TF. The [ZrO2?BTB]C presents
a good candidate for optoelectronics and solar cell applications.
 

Metallic copper nanoparticle (Cu NP)-doped 1D hydroxyapatite was synthesized using a simple chemical reduction
method. To describe the structure and composition of the Cu/HAP nanocomposites, physicochemical techniques such as X-ray
diffraction, Fourier transform infrared spectroscopy, inductively coupled plasma, N2 adsorption-desorption, X-ray photoelectron
spectroscopy, and high-resolution transmission electron microscopy were used. The TEM scan of the Cu/HAP nanocomposite
revealed a rod-like shape with 308 nm length and 117 nm width on average. The catalytic activity of Cu/HAP nanocomposites for
the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4 has been thoroughly investigated. The
0.7% Cu/HAP nanocomposite was shown to have superior catalytic activity than the other nanocomposites, converting 4-NP to 4-
AP in ∼1 min with good recyclability. Moreover, this nanocomposite showed excellent catalytic performance in the organic dye
reduction such as Congo red and acriflavine hydrochloride dyes. The high dispersion of Cu NPs on HAP support, the high specific
surface area, and the small Cu particles contributed to its remarkable catalytic performance.
 

The oxidation of 3′,3″-dibromothymolsulfonphthalein (DBTS) in neutral medium by potassium permanganate multiequivalent oxidant has been studied spectrophotometrically. Pseudo-first-order plots showed inverted S-shape throughout the entire
course of the reaction. The initial rates were found to be relatively fast in the early stages, followed by a decrease in the oxidation
rates over longer time periods in the slow stage. Under pseudo-first-order conditions where [DBTS] ≫ 10 [MnO4-], the
experimental results showed a first-order dependence in [MnO4-] and fractional-first-order kinetics in the [DBTS] concentration.
The formation of 1:1 coordination intermediate complex prior to the rate-determining step was revealed kinetically. In addition, the
intermediate species involving complexes of Mn(V) coordination has been detected. The oxidation product of DBTS was identified
by Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, and gas chromatography-mass analysis. The
obtained results indicated the formation of 2-bromo-6-isopropyl-3-methyl-cyclohexa-2,5-dienone as a derivative oxidation of DBTS
 

Oxidation is the preferred method that used for the removal of colored toxic dyes from wastewater. Various oxidizing agents such as permanganate ion, chromate ion, ferricyanide ion have been studied kinetically to remove these colored dyes from water. In compared to the other oxidizing agents, potassium
permanganate is inexpensive, water-soluble, eco-friendly oxidant, and it can be used in acid, alkaline,
and neutral conditions. In addition, it has been widely used for treatment of pollutants in drinking water and waste-water applications for over 50 years. In this work, the kinetics of bromothymol blue (BTB)
oxidation by KMnO4 were investigated using a conventional spectrophotometer in neutral solutions. The
oxidation reaction rates were accelerated to notable rates by using of Ru (III) as a homogeneous catalyst. The pseudo-1st - order model showed a 1st order in terms of both reactant’s concentration, and
2nd overall reaction. The kinetic data indicated the founding of a 1:1 intermediate species with the intervention of free radicals into the reaction mechanism. At the reaction conditions of [BTB]=1 × 10–5,
[MnO4–] = 4 × 10–4 mol dm–3, and 25 °C, the pseudo-first order rate constant values were calculated to be 1.13×10–4 s–1 without Ru (III) and 1.66×10–4 using Ru(III) as a catalyst (4 × 10–4 mol
dm–3). Considering the kinetic results, a putative the mechanism of the reaction in the stated redox
reaction is postulated and examined. Activation parameters without and with using of Ru (III) were
calculated.