Optimal Conversion Research Articles

Preparation and Characterization of Sulfonated CaO Catalyst for Biodiesel Production from Waste Cooking Oil

Biodiesel production depends on raw materials. Low-quality oils, such as cooking oil, crude palm oil, and sludge oil, are used to reduce costs, and they contain free fatty acids (FFA) and water. Soap can be produced when using the alkaline catalyst during transesterification. In this work, the sulfonation method prepared the esterification of waste cooking oil by sulfonated CaO as a bifunctional catalyst. The sulfonated CaO catalysts were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), temperature-programmed desorption of carbon dioxide and ammonia (TPD), BET surface area, and scanning electron microscopy (SEM). It was observed that the specific surface area, pore volume, and pore diameter of the CaO increased after being sulfonated with a 2 M sulfuric acid solution. It showed a high total surface acidity and basicity, 7.22 and 3.86 mmol/g, respectively. The optimal FFA conversion (84.94 %) from the waste cooking oil was acquired at a reaction temperature of 65 ˚C, a 9:1 MeOH: Oil molar ratio, and 5 wt% catalyst loading for a 3 h reaction time. The 2 M sulfonated CaO catalyst can be reused twice with a high FFA conversion without further treatment under optimized reaction conditions. The 2 M sulfonated CaO catalyst has potential treatment for biodiesel production from high-FFA oils due to its lower production cost and high catalytic activity.

Enhancing the Efficiency of Solar Cells Based on TiO2 and ZnO Photoanodes Through Copper Oxide: A Comparative Study Using Vitis labrusca Extract and N3 Ruthenium Dye

This study investigates the effects of varying CuO doping concentrations on the performance of titanium dioxide (TiO2)-based or zinc oxide (ZnO)-based dye-sensitized solar cells (DSSCs). TiO2 or ZnO mixed with CuO at different weight percentages (0–50 wt %) was employed as photoanodes in DSSCs, prepared via mechanical mixing. X-ray diffraction analysis revealed the structural changes, showing that as the CuO content increased in the hybrid, the CuO peaks (notably at 35.5° and 38.7°) became more prominent. Morphological and elemental characterizations were conducted using SEM and XRF, respectively. The solar cells were photosensitized by Vitis lasbrusca (V.L.) extract and N3 dye. The presence of anthocyanin molecules in the extracted V.L. was confirmed using UV-VIS and FTIR spectroscopy. The electrochemical characterization demonstrated optimal solar conversion efficiencies at a 20% doping level for both photosensitizers. Specifically, in the V.L. dye, TiO2-CuO achieved a conversion efficiency of 7.18%, and ZnO-CuO reached 5.77%. In the N3 dye, TiO2-CuO showed an efficiency of 11.34%, and ZnO-CuO, 9.55%. Notably, undoped photoanodes displayed a significantly lower photovoltaic performance: for V.L. dye, TiO2 showed 1.12% and ZnO 0.87%; for N3 dye, TiO2 showed 6.02% and ZnO 4.39%. Doping was therefore effective, yielding up to a seven-fold increase in performance in the case of V.L. with TiO2, compared to undoped DSSCs. The results demonstrate that using the hybrid photoanode led to a considerable increase in performance compared to using only TiO2 or ZnO photoanodes, highlighting the potential of DSSCs as sustainable energy sources.

WORKING CAPITAL MANAGEMENT AND ACCOUNTING GOING CONCERN

The study evaluated working capital management and accounting going concern of listed manufacturing firms in Nigeria. The objective of the study was to investigate whether cash conversion cycle, current ratio, payable days and inventory days have significant effect on accounting going concern of listed manufacturing firms in Nigeria. The secondary source of data collection was adopted in the study where the purposive sampling technique was used to select a sample size of forty-four (44) listed manufacturing firms in Nigeria for the study. Least Square regression analysis was used in this study and the findings revealed that cash conversion cycle, current ratio, payable days and inventory days have significant effect on accounting going concern of listed manufacturing firms in Nigeria. The study concluded that working capital is a life giving force for any productive economic activity and therefore, its management is categorized among the highly important functions of corporate management. Finally, it was recommended that optimal cash conversion cycle with respect to working capital, liquidity, and trade credits for firms based on sectorial analysis should be developed to enhance their performance of firms in Nigeria.

Novel fabrication of polyethylene glycol/ceramic composite pellets with an excellent phase change shape stable trait and their potential applications for greenhouse insulation

Organic solid–liquid phase change materials (PCMs) face challenges in practical applications due to their susceptibility to leakage during phase transitions. To address this issue, we constructed the polyethylene glycol (PEG)/ceramic pellets (CPs) composite phase change shape stable materials (PCSHs) with thermal energy storage capability, thermal stability, and a firm texture using the melting impregnation method. The PCSHs exhibit remarkable shape stability in the leakage test due to the capillary action and surface tension generated by the micropore structure on their surface. They also can convert light energy into heat and store it as latent heat, achieving an optimal photothermal conversion efficiency of 45.21 % and a maximum melting enthalpy of 13.33 kJ/kg at a PEG loading of ∼ 12 %. An outdoor greenhouse insulation simulation experiment confirmed that the PCSHs can maintain soil temperatures above 30 °C for over 30 min after illumination ceases. This work presents a facile synthesis strategy for shape-stable PCMs with potential applications in greenhouse insulation.

Syngas biological transformation into hydroxyectoine

Syngas from the gasification of organic wastes represents a promising feedstock for fostering a sustainable bioeconomy. However, its potential is currently constrained by the low-value products generated. Osmolytes, such as hydroxyectoine, are high-value compounds, however, their biological production as isolated osmolytes is not yet cost-effective. This study utilized shotgun genomics and laboratory validation to find a carboxydotrophic, halotolerant bacterium, Hydrogenibacillus schlegelii, that could produce hydroxyectoine using H2, CO and CO2 as the sole source of energy and carbon. Subsequently, NaCl concentration, temperature and syngas composition were optimized in semi-continuous bioreactors. Optimal conversion of CO into hydroxyectoine occurred at a gas composition of 70 %:10 % CO:H2 (v/v) (44.8 ± 10.1 mghydroxyectoine·gbiomass-1). NaCl concentrations of 5 % significantly enhanced hydroxyectoine content (46.7 ± 9.5 mghydroxyectoine·gbiomass-1), but negatively affected gas consumption. This study opens new perspectives for the valorisation of syngas into hydroxyectoine, and for new cell platforms for pharmaceutical production based on syngas.

Heterojunction interface engineering enabling high transmittance and record efficiency in Sb2S3 semitransparent solar cell

Antimony sulfide (Sb2S3) is an auspicious contender for semitransparent and tandem solar cells owing to its exceptional optoelectronic characteristics. Yet, complex bulk and heterojunction defects hinder achieving optimal power conversion efficiency (PCE). Although CdS is an established electron transport layer (ETL) in Sb-chalcogenide solar cells benefitting from its exceptional electron mobility (350 cm2V–1s−1) and energy level alignments, its potential contribution has been deplorably overlooked in Sb2S3 semitransparent photovoltaics (STPV). Herein, an optimized TiO2/CdS double ETL strategy is embraced to counteract CdS absorption loss and mitigate the “deep cliff” conduction band off-set at TiO2/Sb2S3 heterojunction. Subsequently, an evolved chemical bath deposition strategy is proposed to deposit a uniform, faster, and comparatively more transparent Sb2S3 absorber layer. A systematic investigation of the absorber layer and in-depth analysis of carrier dynamics at heterojunctions advocate for the mitigation of charge accumulation and recombination at the interface, thereby pledging superior carrier transport. The advantageous gradient energy band alignment of TiO2/CdS/Sb2S3 realized a record PCE of 5.61 % for STPV. Furthermore, the semitransparent device is innovatively employed as a window, enabling transmitted light to be harvested by subsequent Sb2S3 solar cells. It maintains 18 % of its standalone PCE, thereby setting new benchmarks for its practical submissions.

Study on the Pilot-Scale Technology of Ginkgolide B Synthesis by Coprinus comatus

Ginkgo biloba extract (EGB) has been approved by the Food and Drug Administration in the United States for clinical studies on memory disorders. Ginkgolide B (GB) is the major terpene lactone component of EGB and is a specific and potent antagonist of platelet-activating factor (PAF). In a previous study, we reported the medium composition for the conversion of ginkgolides to GB by Coprinus comatus. In the present study, we applied the response surface methodology (RSM) to optimize the conversion conditions in a 20 L fermenter and applied HPLC-MS/MS, circular dichroism (CD) and infrared (IR) spectroscopy analyses, and nuclear magnetic resonance (NMR) to further confirm the sample structure. The optimal conversion conditions consisted of 12.7 L/min of ventilation, a 156 h conversion time, a 132 rpm rotating speed, a 0.04 MPa fermenter pressure, and a 27.8 °C conversion temperature. Under the optimal conditions, the GB conversion rate was 98.62%, and the GB content of the sample was higher than 98%. HPLC-MS/MS, CD, IR, and NMR analyses showed that the molecular formula of the sample was C20H24O10 and the chemical structure of the sample was in good agreement with the standard GB. Our current study lays the groundwork for the industrial production of GB.

Sustainable Manufacturing of 3D-Printed Cyclic Olefin Copolymer Coversheets with Gahnite for Enhanced Silicon Photovoltaic Efficiency

Solar energy plays a vital role in the renewable and pollution-free energy generation. A significant amount of solar energy can be generated through the utilization of solar photovoltaics and collectors. The application of antireflective coatings is an essential factor that effectively absorbs the incident solar radiation and enhances the power conversion efficiency (PCE) of the photovoltaic cells. This study presents the sustainable manufacturing of cyclic olefin copolymer (COC) coversheet on the polycrystalline silicon photovoltaic cells through 3D printing technique to reduce the reflection losses. In addition, gahnite (ZnAl2O4) was added with COC at varying weight percentages to enhance the antireflection characteristics. The PV cells covered by COC with gahnite (COCG) coversheets are analyzed for structural, thermal, mechanical, electrical and optical behaviour. As seen, the COC with 3 wt% of gahnite (CS3) exhibits optimal power conversion efficiency (PCE) in both open (18.06%) and controlled (18.87%) environment. The optical analysis clearly shows that the sample CS3 achieves lowest reflectance of 4.23% and highest transmittance of 95.47%, which significantly increases the absorbance. The results from current investigation demonstrated that COCG could be an ideal antireflection coversheet that effectively improves the PCE of polycrystalline PV cells.

Ion-Mediated Molecular Bridging at Buried Interface Enhances Perovskite Solar Cell Durability.

Engineering heterointerfaces via molecular bridging has been crucial for achieving perovskite solar cells (PSCs) featuring optimal power conversion efficiencies (PCEs) and environmental durability. However, the challenge remains in ensuring interfacial mechanical reliability to enhance the long-term durability of PSCs. Herein, an ion-mediated molecular bridging strategy is intentionally exploited to improve the mechanical integrity between the perovskite bottom and electron-transport layers (ETLs) through balancing interfacial toughness and strength. As a demonstration of the concept, a zwitterionic guanylurea phosphate additive is preburied onto the SnO2 ETL, in which the guanylurea with bifacial NH2 groups servers as a molecular bridge connecting the perovskite and ETL through electrostatic coupling, while the phosphate can interact with charged species at the heterointerface to strengthen the mechanical contact. Benefiting from the robust heterointerfaces, the mechanical durability of flexible PSCs is significantly enhanced, retaining 91.3% of the original efficiency following 6000 bending cycles (bending radius = 3 mm). Additionally, the enhanced mechanical integrity at the buried interface also benefits the charge transfer and chemical stability in rigid PSCs, contributing to PCEs of over 25% as well as thermal stability with T86 of 1200 h under aging at 85 °C.

The effect of experimental diets incorporating fermented soybean meal on growth metrics and utilization of nutrients in broiler chickens

The aim of this study was to explore the impact of fermented soybean meal (FSBM) on the nutritional quality of feed, growth performance indicators, and nutrient utilization in broiler chickens, aiming to overcome the challenges associated with locally produced soybean meal stemming from anti-nutrients and variations in nutritional quality. The study methodology included assessing growth performance metrics through two-way ANOVA statistical analysis and evaluating nutrient utilization in broiler chickens. Results indicated that broiler chickens fed with FSBM exhibited superior performance, displaying the highest average weekly weight gain (452 grams), optimal feed conversion ratio (1.39), extended intestinal length (225 cm), increased intestinal weight (297.5 grams), and heightened activity of digestive enzymes compared to other treatment groups throughout the feeding trials. The results of this study suggest that FSBM’s better digestibility helps broiler chickens grow faster. This makes it a possible replacement for animal protein sources like fish meal in poultry feed production, which is good for both local poultry feed producers and consumers.

Optimal Conversion of Food Packaging Waste to Liquid Fuel via Nonthermal Plasma Treatment: A Model-Centric Approach.

The efficiency of employing a multifactorial approach to enhance the nonthermal plasma (NTP) chemical conversion of solid waste food packaging materials into liquid petroleum hydrocarbons was assessed for the first time in this study. The researchers adopted a hybrid approach which integrated the zero-dimensional (0-D) and response surface model (RSM) techniques. After their application, the researchers noted that these strategies significantly enhanced the model prediction owing to their accurate electrochemical description. Here, the researchers solved a set of equations to identify the optimisation dynamics. They also established experimental circumstances to determine the quantitative correlation among all process variables contributing to food plastic packaging waste degradation and the production of liquid fuels. The findings of the study indicate a good agreement between the numerical and experimental values. It was also noted that the electrical variables of NTP significantly influenced the conversion yield (Yconv%) of solid plastic packaging waste to liquid hydrocarbons. Similarly, after analysing the data, it was seen that factors like the power discharge rate (x1 ), discharge interval (x2), power frequency (x3), and power intensity (x4) could significantly affect the product yield. After optimizing the variables, the researchers observed a maximal Yconv% of approximately 86%. The findings revealed that the proposed framework could effectively scale up the plasma synergistic pyrolysis technology for obtaining the highest Yconv% of solid packaging plastic wastes to produce an aromatics-enriched oil. The researchers subsequently employed the precision of the constructed framework to upgrade the laboratory-scale procedures to industrial-scale processes, which showed more than 95% efficiency. The extracted oil showed a calorific value of 43,570.5 J/g, indicating that the liquid hydrocarbons exhibited properties similar to commercial diesel.

Integration of mathematical and experimental modeling for sustainable phycobiliprotein production via fed-batch cultures

The production of phycobiliproteins, such as cyanobacterial phycocyanins, is a growing interest due to their diverse industrial and biotechnological applications. This study focuses on optimizing phycocyanin production using the strain Potamosiphon sp. through experimental techniques and mathematical modeling in fed-batch cultures. The methodology applied includes determining the kinetic constants by linearizing the Monod equation evaluating the concentrations of biomass, C-phycocyanin (C-PC), nitrates (NO3), and phosphates (PO4). A mathematical model of periodic fed-batch feeding was subsequently established, applying mass conservation principles and evaluating the accuracy of the Monod, Contois, Moser, and Tessier models. The results indicate that phycocyanin production is highly dependent on phosphorus and nitrogen concentrations, with optimal conversion observed at specific levels of these elements (0.832 for phosphorus and 0.805 for nitrogen in terms of C-PC and biomass, respectively). The Tessier model demonstrated the highest accuracy in predicting production and optimizing operational conditions, with a Mean Squared Error (MSE) of 0.005000 for biomass production, 0.200000 for C-PC production, and 0.000010 for substrate consumption. It also achieved high R² values of 0.980 for biomass, 0.999 for C-PC production, and 0.997 for substrate consumption. It presented the lowest Akaike Information Criterion (AIC) scores, indicating its robustness and reliability in modeling these processes and manipulating cultivation conditions and providing adequate nutrition allowed for achieving growth rates of 1.23 g/L and a C-PC concentration of 37 mg/L, which are essential for industrial applications such as natural colorants and antioxidants, among others.

Particle on a Rod: Surface-Tethered Catalyst on CdS Nanorods for Enzymatically Active Nicotinamide Cofactor Generation.

The photochemical generation of nicotinamide cofactor 1,4-NADH, facilitated by inorganic photosensitizers, emerges as a promising model system for investigating charge transfer phenomena at the interface of semiconductors and bacteria, with implications for enhancing photosynthetic biohybrid systems (PBSs). However, extant semiconductor nanocrystal model systems suffer from achieving optimal conversion efficiency under visible light. This study investigates quasi-one-dimensional CdS nanorods as superior light absorbers, surface modified with catalyst Cp*Rh(4,4'-COOH-bpy)Cl2 to produce enzymatically active NADH. This model subsystem facilitates easy product isolation and achieves a turnover frequency (TOF) of 175 h-1, one of the highest efficiencies reported for inorganic photosensitizer-based nicotinamide cofactor generation. Charge transfer kinetics, fundamental for catalytic solar energy conversion, range from 106 to 108 s-1 for this system highlighting the superior electron transfer capabilities of NRs. This model ensures efficient cofactor production and offers critical insights into advancing systems that mimic natural photosynthesis for sustainable solar-to-chemical synthesis.

Modulating stacking mode and molecular polarization in CTF/molecule heterojunction for meliorating photocatalytic CO2 conversion with nearly 100% CO selectivity

Herein, two conjugated molecules, i.e., D-π-A TAPT and non-D-A TAPB, are finely designed to incorporate with covalent triazine framework (CTF) in A-A and A-B stacking mode via π-π interaction, respectively. The transient photocurrent response of the generated AA-CTF/TAPT Z-Scheme heterostructure is 1.14 × 10-7 A, significantly higher than that of the other two metal-free heterostructures (AA-CTF/TAPB and AB-CTF/TAPT). The promoted photocarrier transportation is attributed to strong polarization (dipole moment = 2.634 D) imposed by the D-π-A effect in TAPT that motivates the interfacial charge separation, and the coexisting charge transfer channel built by the ordered A-A stacking mode in AA-CTF that expedites the charge delivery. The photocatalytic CO2 conversion conducted by AA-CTF/TAPT gives the optimal CO conversion rate as 7.47 μmol·g−1·h−1, and with nearly 100 % product selectivity obtained, which is attributable to the lower energy barrier of CO desorption barrier (−1.07 eV) rather than that of CHO* formation (1.52 eV) for generating CH4.

Time-resolved cathodoluminescence measurement of the effects of α -particle-related damage on minority hole lifetime in free-standing n-GaN

Time-resolved cathodoluminescence using 30 keV ultrafast electron pulses has been used to perform direct measurements of the minority hole lifetime τh as a function of 3.7 MeV α-particle fluence in high-quality free-standing n-type GaN substrates. The lifetime damage factor K calculated from these measurements was found to monotonically decrease from 6.9 × 10−2 to 6.4 × 10−4 cm2 s−1 ion−1 with increasing α-fluence from 108 to 1012 cm−2, implying a reduction in trap cross section and/or an aggregation of α-induced traps. The small, ∼200–300 nm, hole diffusion length estimated from the minority hole lifetime for the highest α-fluence necessitates the deployment of α-voltaic device strategies and architectures that emphasize depletion and drift over diffusion for effective charge collection and optimal power conversion efficiency.

Cr-MIL-101 derived nano Cr2O3 for highly efficient dehydrogenation of n-hexane

Nano Cr2O3 (n-Cr2O3) was prepared by the thermolysis of the mesoporous Cr-MIL-101, and its catalytic performance for n-hexane dehydrogenation was investigated and compared with Cr2O3 obtained by traditional method. It is found that dehydrogenation of n-hexane on n-Cr2O3 catalyst can produce n-hexenes and benzene efficiently, and the catalytic performance is related to the calcination temperature. The optimal n-hexane conversion can be obtained on n-Cr2O3 calcinated under 600 °C, is 40.6%, and the selectivities to n-hexenes and benzene are 20.1% and 69.3%, respectively. The conversion of n-hexane for n-Cr2O3 catalyst is decreased with calcination temperature increase, while the catalyst stability in dehydrogenation reaction is enhanced. n-Hexane conversion of p-Cr2O3-1 (obtained by precipitation method) and p-Cr2O3-2 (calcinating Cr(NO3)·9H2O directly) catalysts are very low (<7.5%), and their specific activity for n-hexane dehydrogenation are 1.5 and 1.7 g/(m2·h) respectively, lower than that of n-Cr2O3-600 (2.0 g/(m2·h)). The results of BET, XRD, TEM and FT-IR reveal that n-Cr2O3 is the nanoparticles with large specific surface area that more dehydrogenation active sites are exposed, while p-Cr2O3 is the large particles with extremely low surface area that few dehydrogenation active sites are presented. By contrast, industrial Cr2O3/Al2O3 catalyst possesses the highest specific activity of 2.4 g/(m2·h) due to the dispersion effect of Al2O3. Therefore, highly catalytic activity of n-Cr2O3 for n-hexane dehydrogenation is attributed to the unique properties of small particle, large specific surface area and more exposed active sites. This work not only explains the high dehydrogenation activity of nano-Cr2O3 derived by Cr-MIL-101, but also provides guidance for the precise design and synthesis of high-performance CrOx-based catalyst for the dehydrogenation of alkanes.

Fast biodiesel production via potassium ferrate catalysis at room temperature using used cooking oil and refined canola oil

Abstract As biodiesel is continuously aimed to be a better alternative to petroleum-based diesel fuel, the University of the Philippines Los Baños – Interdisciplinary Biofuels Research Studies Center (UPLB-IBRSC) continues to explore process conversion techniques to improve efficiencies in biodiesel production. In this study, the catalytic activity of potassium ferrate in the transesterification of canola oil and used cooking oil for biodiesel production at room temperature was examined for potential reduction in energy consumption. Parameters such as methanol-to-oil molar ratio, catalyst loading, and reaction time were varied to determine their effects on biodiesel yield and purity. Thin layer chromatography was applied to qualitatively analyze the biodiesel, while ImageJ software was used for purity determination. The characterization analysis confirmed that the refined canola oil used in the study has an acceptable FFA content of 0.06%. On the other hand, the used cooking oil showed an FFA content of 3.71%, which is beyond the desired limit of 2%. Hence, neutralization through the addition of potassium hydroxide was performed, resulting in a lowered FFA content of 0.86%. Experimental results of the parametric and optimization study on used cooking oil showed that an optimum conversion of 86.55% was achieved at a 2:1 methanol-to-oil molar ratio, 5 wt% catalyst loading, and 90 minutes reaction time. Consequently, a yield of 83.21% was attained using refined canola oil at the optimum conditions of 6:1 methanol-to-oil molar ratio, 3 wt% catalyst loading, and 69 minutes reaction time. Generally, findings show that catalyst loading and reaction time significantly affect the biodiesel yield and purity only up to a certain optimum value. The methanol-to-oil ratio, on the other hand, showed to have a significant inverse relationship on yield and purity. Compared to the typical biodiesel production process at 60 °C with up to two hours of reaction time, this study which describes a catalytic process at room temperature and a relatively shorter reaction time, showed the potential to reduce significantly the high energy consumption in biodiesel production.

An Innovative Approach for Oxidative Desulfurization Advancement through High Shear Mixing: An Optimization Study on the Application of Benzothiophene.

Alternative fuels are being explored to mitigate the effects of petroleum-based fuels. Pyrolysis oil from waste tires is a promising alternative fuel; however, it contains very high concentrations of benzothiophene (BT) which are beyond the allowable sulfur limits of Taiwan and the Philippines. Mixing-assisted oxidative desulfurization (MAOD) is a method that removes sulfur from fuel oils by utilizing high-shear mixing and oxidants. In this paper, the oxidation of BT in a model fuel was studied to determine optimal process conditions. Crude Fe(VI) prepared from sludge was used as the oxidant. Using the Box-Behnken design under response surface methodology, the significance of the following independent variables was studied: mixing speed (4400-10 800 rpm), phase transfer agent (PTA) amount (100 to 300 mg), Fe(VI) concentration (400-6000 ppm), and mixing temperature (40 to 60 °C). The results from a comprehensive statistical analysis showed the increase of sulfur conversion with high levels of Fe(VI) concentrations and PTA amounts together with low levels of agitation speeds and temperatures. The BT to BT sulfone conversions from experimental runs ranged from 17% to 64%. The optimum sulfur conversion of 88% for the BT model fuel was reached at the maximum levels of Fe(VI) concentration and mixing speed, along with the minimum levels of PTA concentration and temperature. The optimal MAOD variables were applied to a high-sulfur pyrolysis oil sample, which resulted in a sulfur reduction of 55%. The produced fuel oil meets the sulfur requirements of Taiwan and the Philippines for industrial heating oils. Therefore, the findings of the study support the effectiveness of sludge-derived Fe(VI) in the MAOD of BT in the model fuel and pyrolysis oil under mild process conditions.

Enhance hydrogen storage in lightweight solid-state systems based on Poly(vinylnaphthalene)

This article highlights the potential of poly(2-vinylnaphthalene) (PVN) as a novel light-weight solid-state hydrogen storage system for various applications. With an impressive theoretical gravimetric hydrogen capacity of 5.2 wt.-%, PVN stands out for its attractiveness as a hydrogen carrier. The material possesses advantageous characteristics, including moldability, low toxicity, and ease of storage, making it a promising candidate for both stationary and mobile hydrogen storage applications. Experimental findings demonstrate that PVN can be hydrogenated by up to 76 % utilizing an Ru/Al2O3 catalyst at 250 °C for 24 h. Confirmation of the hydrogenation reaction, which results in poly(2-vinyldecalin), was achieved through characterization techniques such as FTIR, 1H NMR, and spectroscopic ellipsometry. The study of the effects of hydrogen pressure and reaction time identified moderate conditions as favorable, though a further exploration of different catalysts is suggested for optimal conversion. A palladium-based catalyst was employed to release hydrogen from the hydrogenated polymer, demonstrating almost complete reversibility of the hydrogenation of poly(2-vinylnaphthalene) with a dehydrogenation yield of 90 %.

The Impact of Bromine Surface Doping on the Structural, Optical, and Morphological Properties of Bismuth‐Based Perovskite Film as a Light‐Absorber in Perovskite Solar Cells

Bismuth‐based perovskite materials have concerned significant attention due to their low‐toxic and stable properties. However, achieving smooth and dense thin films for the preferential growth of bismuth‐based perovskite along the c‐axis, which is conducive to the preparation of solar cells, is challenging. Therefore, using halogen atoms to partially replace iodine atoms and constrain anisotropic growth has been shown to be an effective method for obtaining high‐quality perovskite films. Herein, Br doping with varying concentrations is used to treat bismuth‐based perovskite films with larger and denser grains compared to those without doping. When a small amount of Br ions is doped, the surface of the perovskite layer becomes more uniform, significantly improving the compactness of the perovskite film. Additionally, proper Br doping can reduce internal defects in the films, effectively inhibiting nonradiative recombination, enhancing light absorption, and increasing carrier lifetime. The optimal power conversion efficiency of Br‐doped bismuth halide perovskite solar cells is found to be 0.136%, compared to 0.087% for pristine devices.