Acid Methyl Ester Research Articles

Isolation, identification, characterization and in vitro assay of saline tolerant endophytes against groundnut root rot caused by Rhizoctonia bataticola (Taub.) Butler

Groundnut, known as Arachis hypogaea L., is India's significant oil seed crop. Dry root rot, caused by Rhizoctonia bataticola, poses a substantial challenge to cultivating groundnuts. During the roving survey, 60.50% dry root rot disease incidence was recorded in Namakkal district, Tamil Nadu. This study aims to acquire salt-tolerant endophytic bacteria residing in groundnuts with significant antagonistic activity against R. bataticola. A total of 27 bacterial strains were isolated from groundnuts. Among these strains, RMV 3 and RMV 2 are the most effective isolates, exhibiting 60.1% and 50% inhibition zones, respectively. The effective isolates were characterized through morphological, biochemical and phytostimulation activities and 16S rDNA sequencing. Among the isolates, RMV 3 and RMV 2 showed positive results for siderophore, indole acetic acid (IAA) and cellulase test. The strain RMV 3 was identified as Bacillus subtilis through 16S rDNA sequencing. GC-MS analysis identified twenty bioactive compounds produced by B. subtilis RMV 3, such as pyrrolo [12-a] pyrazine-14-dione hexahydro-3 (2-methylpropyl) and hexadecanoic acid methyl ester. The crude metabolite assay demonstrated a 96.6% inhibition of R. bataticola by RMV 3. This study demonstrated that Bacillus subtilis RMV 3, which exhibits a robust antagonistic effect on R. bataticola, can potentially be an effective biocontrol agent for groundnut dry root rot.

Analysis of Different Strains Fermented Douchi by GC×GC-TOFMS and UPLC-Q-TOFMS Omics Analysis.

Douchi is a kind of soybean-fermented food in China. To explore the common and differential compounds in different Douchi, Douchi was fermented by Aspergillus niger, Rhizopus arrhizus, and Bacillus circulans, respectively, and co-fermented by the three strains in this study. The common and characteristic flavor compounds and common and characteristic non-volatile components of different strains of fermented Douchi were explored through GC×GC-TOFMS and UPLC-Q-TOFMS omics analysis. The result suggested that Pyrazines, ketones, and alkenes such as tetramethyl-pyrazine, 2,5-dimethyl pyrazine, furaneol, 2,3-butanedione, gamma-terpinene might contribute to the basic flavor of the Douchi fermented by A. niger, R. arrhizus, and B. circulans. Peptides, amines, and flavonoids, such as N-acetylhistamine, 7,3',4'-trihydroxyflavone, (3S,8As)-3-isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione might contribute to the basic function of the above three Douchi. The common metabolic pathways involved in the fermentation were isoflavonoid biosynthesis, flavonoid biosynthesis, etc. Ketones and esters such as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 3-octanone, 5-methylfurfural and nonanal contributed to the unique flavor, while betaine, oleanolic acid, saikosaponin D and leucine might contribute to the unique function of A. niger fermented Douchi. Alkenes, pyrazine, and ketones such as α-terpinene, ethyl-pyrazine, dihydro-3-methyl-2(3H)-furanone, and linalool might contribute to unique flavor, while cordycepin, 2-Phenylacetamide might contributed to the unique function of R. arrhizus fermented Douchi. The unique flavor of B. circulans fermented Douchi might derived from ketones and esters such as 3-acetyl-2-butanone, 2-tridecanone, propionic acid-2-phenylethyl ester, while vitexin, astragalin, and phenethylamine might contribute to the unique function. Compared with single-strain fermented Douchi, the flavor substances and non-volatile components in multi-strain fermented Douchi were more abundant, such as hexadecanoic acid methyl ester, benzeneacetic acid ethyl ester, 9,12-octadecadienoic acid ethyl ester, nuciferine, and erucamide. It was speculated that there were common and differential substances in Douchi fermented by Aspergillus niger, Rhizopus arrhizus, and Bacillus circulans, which might contribute to the basic and unique flavor and function. Compared with single-strain fermented Douchi, the flavor substances and metabolites in multi-strain fermented Douchi were more abundant. This study provided a reference for the research of flavor and functional substances of Douchi.

Phytochemical analysis on the female cone of Araucaria bidwillii Hook

In this work, the first phytochemical analysis ever performed on a whole cone of Araucaria bidwillii Hook. is presented. This was carried out by means of column chromatography, NMR spectroscopy and MS spectrometry on the female cone, evidencing the presence of forty metabolites, thirty-three of which are primary whilst the remaining are non-volatile secondary. A chemophenetic evaluation was also performed reporting seven new compounds for the species i.e. β-sitosterol (5), 15-agathic acid methyl ester (6), methyl (E)-communate (7), shikimic acid (8), gallic acid (9), p-hydroxy-benzoic acid (10) and quinic acid (11). Throughout this evaluation some important qualitative phytochemical differences among this female cone, its seeds and the few other studied cones of the species comprised in the family, were evidenced. These whole results provide more information on the phytochemistry of this organ and of the species, in general, but also underline the need to perform more studies.

Investigation of photovoltaic properties of poly(3-hexylthiophene): Polynaphthalene-bithiophene heterostructure devices

This work is focused on photoluminescence (PL) study of a P-type donor and two N-type acceptor semiconducting materials for an efficient organic photovoltaic (OPV) device fabrication. PL quenching of P-type poly(3-hexylthiophene) (P3HT) is investigated in solution containing N-type fullerene phenyl-C61-butyric acid methyl ester (PCBM) and N-type polynaphthalene-bithiophene (N2200) independently using chloroform solvent. Here, we studied the charge transfer behavior using PL spectroscopy and the experimental results of this investigation confirmed that PL quenching of P3HT by N2200 is more efficient than by PCBM. According to our findings, P3HT:N2200 is a more promising candidate than P3HT:PCBM blend solution for efficient photovoltaic devices. This work also incorporated the fabrication processes and the characterizations of the OPV device using the P3HT:N2200 blend as an active layer. The structure of the fabricated device is ITO/PEDOT:PSS/P3HT:N2200(1:1)/BCP/Al, with three different concentrations 10 mg/ml, 12 mg/ml, and 20 mg/ml of P3HT:N2200 active material with/without the addition of diiodooctane (DIO), with/without methanol treatment, and with/without annealing on the top of the active layer. The device with 12 mg/ml P3HT:N2200, with DIO and methanol treatment showed the best performance with 0.36% power conversion efficiency (PCE) and 45.0 % fill factor with 1.76 mA/cm2 maximum short circuit current density (JSC).

Analysis of organic chemical compounds in Moringa oleifera L. using the gas chromatography-mass spectrometry method

Abstract Using a unique approach, a study was adopted to identify the organic chemical content in Moringa oleifera leaves by utilizing GC-MS. The Integrated Research and Testing Laboratory of Gadjah Mada University (LPPT-UGM) conducted the research in Yogyakarta from April to June 2024, using leaf extracts of M. oleifera L. varieties from the Mapanget Barat district area of Manado City, North Sulawesi Province. The chromatogram data underwent quantitative and qualitative analysis to identify and enumerate the organic molecules that comprise secondary metabolites. The analysis of the GC-MS results revealed the existence of several secondary metabolite compounds in the Moringa oleifera leaf extracts, including Decanoic acid, ethyl ester; Dodecanoic acid, ethyl ester; Neophytadiene (3,7,11,15-tetramethyl-2-hexadecen-1-ol); Hexadecanoic acid, methyl ester; trans-13-octadecenoic acid (oleic acid) methyl ester; Hexadecanoic acid, ethyl ester; trans-13-Octadecenoic acid, methyl ester; Methyl stearate; Phytol; Ethyl 9,12,15-octadecatrienoate; Eicosanoic acid, methyl ester; and Diisooctyl phthalate. These compounds are classified as terpenoids and fatty acids and have the potential for use as biopesticides, providing a sustainable solution for pest control in agriculture. The most abundant compound identified was phytol, a terpenoid, with a retention area of 14.78%. The findings suggest that M. oleifera leaves contain different secondary compounds that might be used as agricultural biopesticides.

Synthesis, physicochemical properties and in vitro cytotoxic activity of aziridine-containing derivatives of 1,3,5-triazine

6-{[4-(Aziridin-1-yl)-6-chloro-1,3,5-triazin-2-yl]amino}-hexanoic acid methyl ester and sodium salt were synthesized from cyanuric chloride. The sodium salt would interact with free radicals of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and inhibit hemolysis induced by Radachlorin. Both compounds interact with DNA with Kbin values of 1.09 × 107 and 0.99 × 107 dm3 mol−1, respectively; they also demonstrate cytotoxic activity against human cancer cell lines.

Basicity-tuned graphitic carbon nitride supported MgO heterogeneous catalysts for efficient transesterification of groundnut oil to biodiesel

Quality and quantity of biodiesel derived from oil depend on the type of feedstock and the transesterification process. To maximize biodiesel production efficiency and ensure the desired fuel quality, it is crucial to develop and optimize feedstock-specific production processes. This study reports on the transesterification of groundnut oil using a heterogeneous catalyst. Magnesium oxide (MgO) and its composites with graphitic carbon nitride (g-C3N4) at 10, 30, and 50 wt% (MG10, MG30, MG50) were used. The composite catalyst combines basic sites from MgO and Lewis acid sites from the nitrogen atoms in the g-C3N4 triazine unit, giving rise to synergistic effects that enhances biodiesel production. MgO nanoparticles were synthesized via precipitation, followed by calcination at 500 °C, and MgO/g-C3N4 composites were prepared by grinding at different ratios. Morphological and structural studies confirmed material characteristics. BET analysis indicated an increased surface area of 71.39 m2/g, enhancing catalytic activity, while SEM revealed the agglomerated g-C3N4 and the cubic morphology of MgO. Response surface methodology was used to optimize catalyst loading, temperature, and reaction time parameters. The optimal conditions for biodiesel conversion using MG50 composite was determined to be methanol/oil ratio of 6:1, 2.5 wt% catalyst loading, 41.7 °C reaction temperature and spanning 52 min of reaction, yielding 94 % efficiency. GC–MS analysis confirmed successful transesterification, identifying key fatty acid esters such as ethyl oleate (34.72 %) and hexadecanoic acid methyl ester (7.69 %). This work supports further research into feedstock-specific catalysts for industrial biodiesel applications.

Enhancing Indoor Photovoltaic Performance of Inverted Type Organic Solar Cell by Controlling Photoactive Layer Solution Concentration

With the development of various low-power indoor electronic devices, indoor photovoltaics, particularly organic solar cells (OSCs) have attracted a lot of interest in recent years. Increasing the light absorption and suppressing the leakage current are pivotal to improve the indoor photovoltaic performance of OSCs. In this study, the carbon quantum dots (CQDs)-incorporated photoactive layer solution concentration was varied to improve the photovoltaic performance under 1-sun and indoor white LED illumination. The photoactive layer was composed of (6,6)-phenyl-C61-butyric acid methyl ester) (PCBM) as the acceptor and poly(3-hexylthiophene) (P3HT) as the donor. The ZnO electron transport layer was deposited on fluorine-doped tin oxide (FTO)-coated glass substrates using a spin coating technique. The photoactive layers with different solution concentrations were spin coated on top of the ZnO layer. For device completion, silver anode was thermally evaporated. It is interesting to find that the optimum solution concentration obtained under white LED illumination is larger than that under 1-sun illumination. The maximum power conversion efficiency (PCE) of 0.95% was obtained under 1-sun illumination for device with the solution concentration of 36 mg/mL, whereas, under white LED illumination, the highest PCE of 3.59% was obtained for the device with solution concentration of 48 mg/mL.The discrepancy is ascribed to the higher light absorption of thicker photoactive layer and less significant charge recombination loss under weak light intensity. This study highlights the importance of using different optimization strategies to improve the photovoltaic performance of OSCs for outdoor and indoor applications.

Telmisartan potentiates the ITE-induced aryl hydrocarbon receptor activity in human liver cell line.

Telmisartan is an angiotensin receptor blocker (ARB) approved by the Food and Drug Administration of the US for the treatment of hypertension. It possesses unique pharmacologic properties, including the longest half-life among all ARBs; this leads to a 24-h sustained reduction of blood pressure. Besides well-known antihypertensive and cardioprotective effects, there is also strong clinical evidence that telmisartan confers renoprotection. Aryl hydrocarbon receptor (AhR) belongs to the steroid receptor family. 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) is an endogenous ligand of AhR. Cytochrome P450 (CYP) 1A1 is an AhR-target gene. In this article, we demonstrated that telmisartan (2.5-60μM) enhanced CYP1A1 promoter activity and expressions of mRNA and protein. Telmisartan-induced CYP1A1 expression was blocked by the AhR antagonist CH-223191 in liver cell lines and was negligible in the AhR signaling-deficient mutant cells. In addition, telmisartan induced transcriptional activity mediated by aryl hydrocarbon response element in both human and mouse cells, and was able to induce AhR translocation into the nucleus. Accordingly, telmisartan is an AhR agonist. It also acted synergistically with ITE to further enhance the expression of CYP1A1 mRNA and protein. This synergistic effect was more pronounced in cells with AhR overexpression compared to those without. AhR activity has strong association with the progression of chronic renal disease. Our study demonstrated that telmisartan is an AhR agonist and has synergistic effect with ITE, an indole derivative, to potentiate the effect on AhR. This finding may provide additional clues about the mechanism of the protective effect of telmisartan on the kidney.

An In Vitro, In silico, GCMS and LCMS Investigation of Crinum jagus (J. Thomp.) Dandy Bulb for Lead Anti-Hepatocellular Carcinoma Compounds

Hepatocellular carcinoma is a leading cause of cancer-related death around the world. In this study, the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to investigate the anticancer activity of five chromatographic fractions of Crinum jagus methanol bulb extract against the hepatocellular carcinoma (HepG2) cell line. The IC50 value was used as a measure of anticancer activity. The most active fraction was analyzed using GCMS and LCMS. The binding energies of the identified compounds with Caspase-3, Caspase-9 and EGFR were evaluated and compared with that of the standard drug, Sorafenib. The compounds' drug-likeness was evaluated by applying Lipinski's rule of five. The IC50 value of the most active fraction was 37 μg/ml. Nineteen (19) compounds, primarily fatty acids, fatty acid esters, and flavonoids, were identified from the fraction by GCMS and LCMS analysis. Of the nineteen (19) compounds identified in the most active fraction, linoelaidic acid (-8.23 kcal mol-1), hexadecanoic acid (-7.96 kcal mol-1) and 9,12-Octadecadienoic acid (-7.78 kcal mol-1) had better binding affinity for Caspase-3 than Sorafenib; hexadecanoic acid methyl ester (-8.10 kcal mol-1) and pentyl linoleate (-8.00 kcal mol-1) had comparable binding energy with Sorafenib (-8.47 kcal mol-1) against Caspase-9; while hexadecanoic acid (-8.29 kcal mol-1), linoelaidic acid (-8.58 kcal mol-1), and pentyl linoleate (-8.66 kcal mol-1) had better binding energy than Sorafenib (-8.24 kcal mol-1) against EGFR. These compounds passed Lipinski’s test for drug-likeness. The study's findings lend credence to the plant's traditional use as a cancer remedy.

Cold-Active Lipase from the Ice Cave Psychrobacter SC65A.3 Strain, a Promising Biocatalyst for Silybin Acylation.

Cold-active lipase from the psychrophilic bacterial strain Psychrobacter SC65A.3 isolated from Scarisoara Ice Cave (Romania) was cloned and characterized as an extremophilic biocatalyst for silybin acylation. Structural analyses highlighted conserved motifs confirming a functional lipase and the presence of primary structure elements for catalysis at low temperatures. The recombinant enzyme (PSL2) heterologously expressed in Escherichia coli was purified in one step by affinity chromatography with a yield of 12.08 ± 1.72 µg L-1 of culture and a specific activity of 20.1 ± 3.2 U mg-1 at 25 °C. Functional characterization of PSL2 showed a neutral (7.2) optimal pH and a high thermal stability up to 90 °C. Also, this lipase was stable in the presence of different organic solvents, with 60% residual activity when using 20% DMSO. Kinetic measurements indicated performant catalytic efficiency of PSL2 for different short and long chain fatty acids, with Km in the mM range. The catalytic activity of PSL2 was assessed for silybin acylation with various fatty acids and fatty acid methyl esters, demonstrating a 90% silybin conversion when methyl decanoate ester was used. This result clearly highlights the biocatalytic capability of this new cold-active lipase.

Exploring Alkali Hydroxide Influence on Calcium Titanate Formation for Application in Biodiesel Catalysts

Biodiesel has been recognized as the most widely utilized biofuel around the world due to its significant role in reducing the consumption of crude oil and lowering environmental pollution levels. By serving as a renewable alternative to fossil fuels, bioethanol helps decrease greenhouse gas emissions and contributes to a more sustainable energy future. Traditionally, alkali hydroxides like NaOH and KOH have been mainstays in biodiesel synthesis. However, their overuse can lead to unwanted byproducts and operational complexities. Since calcium titanate can occur at a strong base condition, it presents an alternative avenue worth exploring. In this study, we investigate the influence of alkali hydroxides, namely LiOH, NaOH, and KOH, on the formation of calcium titanate through hydrothermal methods, with varying heating times. We aim to understand how different hydroxides affect the synthesis process and the resultant properties of calcium titanate. We delve into the vibrational properties of Ca‒O‒Ti and Ti‒O bonds using Fourier transform infrared spectroscopy (FTIR), confirming the presence of calcium titanate (JCPDS No.42-0423) through X-ray diffractometry (XRD). This thorough characterization provides insight into the structural integrity and composition of the synthesized materials. Moreover, scanning electron microscopy (SEM) reveals the intriguing cube-like morphology of calcium titanate, offering visual evidence of its unique structure. The fatty acid methyl ester Iimpressively, our results show that calcium titanate synthesized in 7 M NaOH and KOH solutions, heated for 24 hours, emerges as a promising biodiesel catalyst. We observe fatty acid methyl ester provides the percentages of 63.67% and 90.02%, respectively, indicating the catalytic efficacy of these materials in biodiesel production. These findings not only contribute to the understanding of calcium titanate synthesis but also pave the way for a sustainable future in biodiesel production by introducing efficient and eco-friendly catalysts.

Induced Electron Traps via the PCBM in P(VDF-HFP) Composites to Enhance Dielectric and Energy Storage Performance.

Polymer-based composites with excellent dielectric properties are essential for advanced energy storage applications. In this work, the [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as a filler was incorporated into the poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) composite to improve its dielectric performance. P(VDF-HFP) composite films with varying PCBM concentrations were prepared via solution casting and their dielectric, energy storage, and charge-discharge properties were characterized. It was found that the doped PCBM could introduce new charge traps with an energy level of 1.25 eV that modulate charge transport and energy storage characteristics of the polymer matrix. The dielectric constant of the composites was enhanced to the maximum of 10.87 as 0.2 vol% PCBM was added, while the breakdown strength reached 455 MV/m, achieving an energy density of 7.38 J/cm3, which is 33% higher than the pristine P(VDF-HFP) film. Furthermore, the charge-discharge efficiency of the composites was enhanced 66% under the electric field of 300 MV/m. These results demonstrate that PCBM significantly improves the dielectric and energy storage properties of P(VDF-HFP) composites, providing a promising approach for the development of high-performance dielectric materials in flexible energy storage devices.

Maximization of Biodiesel production from oil that produced during salmon smoking process with high amount of omega-3 by using homogenous catalyst.

The escalating global demand for oil, coupled with declining fossil fuel production, prompts the urgent exploration of renewable alternatives. To address this challenge, researchers are actively seeking environmentally friendly fuels like biodiesel. Among potential feedstocks, oil that is produced from salmon smoking process during industry emerges as a promising option. Smoked salmon oil could be a challenge when producing biodiesel due to its high content of omega-3 compounds. Using homogenous commercial catalyst from alkali to achieve the highest yield from salmon smoking oil was the aim of the current study. A Box-Behnken design and response surface methodology in Design Expert software (version 13) was used to study the effect of four main factors on the biodiesel yield from salmon smoking oil. The optimum biodiesel values were 70°C, 90 min, 0.753 wt.%, and 20 wt.% for temperature, reaction time, sodium hydroxide concentration, and methanol concentration, respectively. At these optimum values, the highest biodiesel production was 92.0% with fatty acid methyl ester contents of 83.4% and conversion efficiency of 77%. Thin-layer chromatography and thermal gravimetric analysis confirmed the successful production of biodiesel at optimized conditions. Using Aspen Plus simulation software confirmed the cost-effectiveness of the homogenous catalyst used for enhancing biodiesel production from salmon smoking oil.

Nematicidal efficacy of Cymbopogon nardus, Pelargonium graveolens essential oils and Annona squamosa extract against Meloidogyne incognita and M. graminicola

A crude hexane extract of seed kernel was processed into fatty acid methyl esters (FAME) using methanolic-sulfuric acid. Herbal mixtures (seed extracts of A. squamosa and essential oils of Cymbopogon nardus (citronella) and Pelargonium graveolens (geranium)) were evaluated against root knot nematode (Meloidogyne spp). The mortality of J2s of M. incognita in hexane and methanol extracts (AHE+AME) of A. squamosa with geranium oil (GO) ranged from 50.75-89.75% to 71.50-99.00% at 31.25 to 1000 μgmL-1 in 24 to 96 hours. The number of galls after CO+AHE+AME treatment was 4.0 ± 0.0 and 5.67 ± 0.58 galls/seedling and were recorded at 1000 and 500 μgmL-1 treatments on 30 days after inoculation, compared to carbofuran (3.0 ± 0.0 and 4.3 ± 0.6 galls/seedling) at 1000 and 500 μgmL-1 and velum prime (3.6 ± 0.6 and 4.6 ± 0.6 galls/seedling) at 1000 and 500 μgmL-1. The maximum shoot length of brinjal seedlings was recorded in CO+AHE+AME treatment compared to carbofuran (47.3 ± 0.6cm) and velum prime (48.7 ± 0.6 cm) at 1000 μg mL-1 in soil drenching application. Methanol and hexane extracts (AHE+AME) obtained from Annona squamosa seeds were investigated for their nematicidal properties. M. graminicola in direct-seeded rice at the nursery level and M. incognita in brinjal (eggplant) were controlled for up to sixty days when treated with these mixtures.

Antiproliferative Effects of Ajuga orientalis Methanolic Extract: In Vitro and In Silico Insights

AbstractAjuga orientalis, a perennial herb from the Lamiaceae family, is traditionally used in Jordanian folk medicine for its therapeutic properties. This study evaluates the phytochemical profile, cytotoxicity, drug‐likeness, and molecular docking of the methanolic extract of A. orientalis to explore its potential as a source of novel therapeutic agents. GC‐MS analysis identified 21 compounds, including oleic acid methyl ester (27.1%) and palmitic acid (12.5%). The extract demonstrated significant concentration‐dependent cytotoxicity against RAW264.7 macrophage cells, with an IC50 of 91.5 µg/mL. Molecular docking studies revealed fundamental interactions of phytochemicals with cancer‐related proteins, including VEGFR2 and TLR4/MD‐2, showing strong binding affinities. Notably, 1,7‐di(2,5‐dimethylphenyl)‐2,2,4,4,6,6‐hexamethyl‐1,3,5,7‐tetraoxa‐2,4,6‐trisilaheptane and the 2TBDMS derivative of 4‐hydroxybenzeneacetic acid exhibited promising interactions, indicating potential for inhibiting angiogenesis and modulating immune responses. Drug‐likeness evaluation of 18 compounds showed that 11 meet the criteria for oral bioavailability, though some challenges for drug development remain. This research underscores the therapeutic potential of A. orientalis compounds in cancer treatment and immune modulation, suggesting further experimental validation and development of these bioactive compounds.

Special-point approach for optical absorption coefficient calculations on two-dimensional self-assemblies of type-II perovskite quantum dots

All-inorganic perovskite quantum dots with the usual cubic shape have emerged as a successful and low-cost alternative to electronically functional nanomaterials motivating various fields of applications, including high-efficiency photovoltaics. Here, we present an efficient and almost analytic approach for optical absorption coefficient calculation on self-assembled perovskite quantum dot films with type-II band alignment. The approach takes advantage of the special point technique for integration over the two-dimensional Brillouin zone, which minimizes the computational cost. The set of special wave-vector points is generated using the Monkhorst and Pack method. The optical absorption spectrum for phenyl-C60-butyric acid methyl ester (PCBM)/CsPbI3quantum dot films is computed, in good agreement with the experiment assuming a homogeneous linewidth of 50 meV and considering a ten special-point set. We show that light absorption in these systems is a cooperative optoelectronic property resulting from the quantum-mechanical coupling between perovskite nanocubes, leading to extended system states. The generality of this approach makes it suitable for calculating the optical absorption coefficient in a broad class of perovskite quantum dot systems.

Efficient and stable inverted perovskite solar cells enabled by homogenized PCBM with enhanced electron transport

Fullerene derivatives are extensively employed in inverted perovskite solar cells due to their excellent electron extraction capabilities. However, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) agglomerates easily in solution and exhibits a relatively low ionization barrier, increasing charge recombination losses and charge accumulation in the interface. Here, tetramethylthiuram disulfide (TMDS) is introduced into the PCBM solution to induce the formation of reducing sulfur radicals through UV light irradiation, allowing for n doping of the PCBM material. The resulting modified PCBM layer exhibits enhanced conductivity and electron mobility, significantly suppressing charge recombination. As a result, the resulting devices incorporating TMDS achieve a champion efficiency of 26.10% (certified 25.39%) and 24.06% at a larger area (1.0 cm2) with negligible hysteresis. More importantly, the optimized devices retain 95% and 90% of their initial efficiency after 1090 h under damp heat testing (85 °C and 85% relative humidity) and after 1271 h under maximum power point-tracking conditions, respectively.

Elucidating the hysteresis effect in printed flexible perovskite solar cells with SnO2 quantum dot- and PCBM-based electron transport layers

Recently, flexible perovskite solar cells (FPSCs) fabricated using solution-processed printing techniques have garnered significant attention. However, challenges remain in achieving cost-effective, scalable manufacturing under ambient conditions and ensuring stable, efficient devices. This study focuses on fabricating printed FPSCs using the slot-die coating technique and examines the impact of SnO2 quantum dot (QD) and (6,6)-Phenyl C61 butyric acid methyl ester (PCBM) based electron transport layers (ETLs) on device performance and hysteresis. Experimentally results show that SnO2 QD-based devices exhibited favorable photovoltaic properties but significant hysteresis compared to PCBM-based devices. Numerical simulations have shown that the hysteresis effect in devices is influenced not only by the higher concentration of mobile ions in the perovskite layer of PCBM-based devices compared to SnO2 QD-based devices, but also by the more effective redistribution of these ions during forward and reverse J-V scans. The results provide insights into the behavior of printed FPSCs with different ETLs, contributing to the development of high-performance, hysteresis-free printed FPSCs.

Treatment of acidic crude palm oil using supported benzenesulfonic acid-based deep eutectic solvents in trickle bed reactor

In this study, a deep eutectic solvent (DES) from benzenesulfonic acid and choline chloride (BZSA-ChCl-DES) was prepared for the treatment of high free fatty acids (FFA) in acidic crude palm oil (ACPO). The DES was impregnated into activated carbon (AC-DES) to produce a supported catalyst used in a trickle bed reactor (TBR) for FFA esterification. Under optimal conditions, using 8 g of AC-DES at 60 °C, with ACPO and methanol flow rates of 1 mL/min and 4 mL/min, respectively, the TBR successfully treated 3.5 L of ACPO. A batch reactor, used for comparison, showed that the continuous TBR process required less catalyst per gram of treated oil (2.87 mg catalyst/g) which can enhance the recyclability. Moreover, the continuous process could sustain up to five recycle runs that can treat 1.5 L under optimal conditions (3.5 wt% catalyst dosage, 10:1 M ratio, 60 °C reaction temperature, and 30 min). This approach presents a promising continuous approach for converting high FFA to fatty acid methyl ester (FAME) for biodiesel production.