A novel gallium-based MOF, termed Ga-BPT SC (single crystal) and Ga-BPT P (powder), was synthesized.

Remote epitaxy through graphene enables the fabrication of freestanding membranes, facilitating the "peel-and-stack" process for semiconductor hetero-integration. While previous studies have emphasized graphene thickness, substrate bonding ionicity, and damage-free transfer of graphene for implementing remote epitaxy, the impact of nanoscale microscopic defects in graphene remains unexplored. Metal-organic chemical vapor deposition (MOCVD) of GaN requires high temperatures and a radical reaction environment, which can damage graphene. This study investigates the effects of chemical doping and nanoscale defects in graphene on remote epitaxy during MOCVD growth of GaN crystallites on graphene-coated Al2O3 for understanding the early growth stage and the resulting crystal quality. Three distinct modes are identified: remote epitaxy, anchored remote epitaxy, and epitaxial lateral overgrowth (ELOG). Pristine graphene enables pure remote epitaxy of well-aligned, strain-relaxed GaN crystallites. N-doped graphene promotes chemically anchored nucleation, causing slightly misaligned crystallites due to altered remote atomic interaction, newly termed "anchored remote epitaxy". Graphene pinholes induce direct GaN-Al2O3 covalent bonding for ELOG, resulting in significant compressive strain in GaN. How graphene's chemical and physical defects affect epitaxial crystallite quality (i.e., alignment, strain relaxation, density) is further explored based on bonding mechanisms, providing insights into remote epitaxy for next-generation semiconductor fabrication.

The increasing concern about environmental degradation and an energy crisis due to geopolitical conflicts, economic sanctions, and worsened energy security has prompted energy researchers to find environmentally friendly and renewable sources as an alternative to fossil fuel sources. Hydrogen is one of the most suitable replacements for fossil fuels due to its good thermal properties, wide applicability, multiple sources, and being carbon-free. Hydrogen can be produced sustainably from different biomass sources through biological and thermochemical pathways. This manuscript aims to present a comprehensive analysis of current approaches for producing hydrogen from biomass sources, elucidating recent advancements in this domain. The manuscript outlines the benefits and drawbacks of different approaches. Furthermore, a thorough bibliometric analysis using VOSviewer software was carried out for the years 2000–2023, covering 1840 relevant references. The incorporation of an extensive bibliometric analysis enhances the scholarly depth of the research. Through the mapping of historical and contemporary research emphases, significant contributors, and emerging trends, the paper provides a precise visual depiction of the research landscape. This not only contributes to a nuanced comprehension of the field's present condition but also functions as a valuable instrument for researchers in strategizing future studies.

The vast compositional and configurational spaces of multi-element metal halide perovskites (MHPs) result in significant challenges when designing MHPs with promising stability and optoelectronic properties. In this paper, we propose a framework for the design of B-site-alloyed ABX3 MHPs by combining density functional theory (DFT) and machine learning (ML). We performed generalized gradient approximation with Perdew–Burke–Ernzerhof functional for solids (PBEsol) on 3,159 B-site-alloyed perovskite structures using a compositional step of 1/4. Crystal graph convolution neural networks (CGCNNs) were trained on the 3159 DFT datasets to predict the decomposition energy, bandgap, and types of bandgaps. The trained CGCNN models were used to explore the compositional and configurational spaces of 41,400 B-site-alloyed ABX3 MHPs with a compositional step of 1/16, by accessing all possible configurations for each composition. The electronic band structures of the selected compounds were calculated using the hybrid functional (PBE0). Then, we calculated the optical absorption spectra and spectroscopic limited maximum efficiency of the selected compounds. Based on the DFT/ML-combined screening, 10 promising compounds with optimal bandgaps were selected, and from among these 10 compounds, CsGe0.3125Sn0.6875I3 and CsGe0.0625Pb0.3125Sn0.625Br3 were suggested as photon absorbers for single-junction and tandem solar cells, respectively. The design framework presented herein is a good starting point for the design of mixed MHPs for optoelectronic applications.

The eco-friendly water/PVA system (PVA = polyvinyl alcohol) was employed to granulate SBMOF-1 powder to form SBMOF-1@20 %PVA beads. The granulated beads maintained the high crystallinity of SBMOF-1 with the emergence of meso/macropores at 3.8, 50, and 76 nm. Owing to its benefit for mass diffusion, the presence of meso/macro porosity led to ∼128 % enhancement of the Xe uptake capacity (based on SBMOF-1) of SBMOF-1@20 %PVA beads over SBMOF-1 powder at 20 % Xe broke through. This further enabled Xe/Kr separation from the simulated used nuclear fuel (UNF) reprocessing off-gas. Moreover, an easier and faster regeneration of SBMOF-1@20 %PVA over SBMOF-1 powder through helium purge was obtained at room temperature. These findings demonstrate an enhanced working efficiency of the granulated SBMOF-1 beads over the powder samples by improving uptake capacity, saving energy for regeneration at high temperatures and cooling time after the heating-up regeneration, thereby highlighting the benefit of our engineering protocol in enhancing separation performance via MOF granulation.

The eco-friendly water/PVA system (PVA = polyvinyl alcohol) was employed to granulate SBMOF-1 powder to form SBMOF-1@20%PVA beads. The granulated beads maintained the high crystallinity of SBMOF-1 with the emergence of meso/macropores at 3.8, 50, and 76 nm. Owing to its benefit for mass diffusion, the presence of meso/macro porosity led to similar to 128% enhancement of the Xe uptake capacity (based on SBMOF-1) of SBMOF1@20%PVA beads over SBMOF-1 powder at 20% Xe broke through. This further enabled Xe/Kr separation from the simulated used nuclear fuel (UNF) reprocessing off-gas. Moreover, an easier and faster regeneration of SBMOF-1@20%PVA over SBMOF-1 powder through helium purge was obtained at room temperature. These findings demonstrate an enhanced working efficiency of the granulated SBMOF-1 beads over the powder samples by improving uptake capacity, saving energy for regeneration at high temperatures and cooling time after the heating-up regeneration, thereby highlighting the benefit of our engineering protocol in enhancing separation performance via MOF granulation.

Recently, there has been a rising demand for hybrid catalysts with heterojunctions between two catalytic materials. In particular, hybrid materials based on Pt and transition metal dichalcogenides (TMDCs) have been the focus for improving electrocatalysts. However, finding a TMDC support to ensure the long-term stability of Pt/ TMDC hybrid catalysts with high activity remains a challenge. In this paper, we present a hybrid electrocatalyst comprising ReS2 nanoflowers and Pt nanoclusters (NCs) for efficient hydrogen evolution reaction (HER). The hybrid catalyst enhanced hydrogen desorption via charge transfer from Pt to ReS2, demonstrating good HER activity with outstanding durability and a low overpotential (20 mV at 10 mA cm-2) compared with conventional Pt/C catalysts.

Porous carbons can be prepared from crystalline metal–organic frameworks (MOFs) by pyrolysis. However, MOF-derived porous carbons (denoted as MPCs) are mostly composed of microporosity, potentially causing diffusional limitation during guest transport. To overcome the potential diffusional limitation of MPCs due to pore size constraints, secondary meso- or macropores need to be introduced in the MPCs. Our strategy is to granulize MOF-808 nanoparticles via spray drying, followed by pyrolysis and HF etching, yielding MPC granules with a bimodal micro-mesoporous structure, in which the micropores originate from intrinsic pores of MOF-808 and the mesopores stem from interparticle spaces between assembled MOF-808 particles. Graphical abstract

A wide variety of metal organic frameworks (MOFs) created by periodic combinations between organic ligands and metal ions or metal-oxo clusters have paved the way for the development of energy-efficient membrane-based separations that potentially can serve as feasible substitutes for thermal counterparts. Although significant progress has been made in the synthesis of polycrystalline MOF membranes over the last decade, only a limited number of MOFs have been utilized for relevant research. The lack of a clear solution for intercrystalline defects, non-selective diffusion pathways in polycrystalline membranes, is most likely a deciding factor behind the delay. Postsynthetic modifications (PSMs) are considered as newly emerging strategies for offering polycrystalline MOF membrane diversity by utilizing existing membranes as a platform and improving their separation functions via physical and/or chemical treatments and therefore, neither designing new MOFs nor customizing membrane synthesis techniques for targeted MOFs are required. In this minireview, eight subclasses ((1) covalent tethering, (2) intercrystalline defect plugging, (3) intracrystalline defect healing, (4) inclusion of functional materials in pores, (5) stiffening, (6) ligand exchange, (7) amorphization, and (8) MOF to MOF transformation) of PSM strategies, that have been applied to polycrystalline MOF membranes, are summarized, and challenges and future directions are discussed.

We propose a metasurface antenna capable of real time holographic beam steering. An array of reconfigurable dipoeles can generate on demand far field patterns of radiation through the specific encoding of meta atomic states. i.e., the configuration of each dipole. Suitable states for the generation of the desired patterns can be identified using iteartion, but this is very slow and needs to be done for each far field pattern. Here, we present a deep learning based method for the control of a metasurface antenna with point dipole elements that vary in their state using dipole polarizability. Instead of iteration, we adopt a deep learning algorithm that combines an autoencoder with an electromagnetic scattering equation to determin the states required for a target far field pattern in real time. The scattering equation from Born approximation is used as the decoder in training the neural network, and analytic Green's function calculation is used to check the validity of Born approximation. Our learning based algorithm requires a computing time of within in 200 microseconds to determine the meta atomic states, thus enabling the real time opeartion of a holographic antenna.

In this report, a few unit-cell thick ZIF-8 nanosheets with (002) basal planes exposed with 4-membered windows were synthesized by using sodium dodecyl sulfate, an anionic surfactant as a structure directing agent, which were used as fillers to fabricate mixed matrix membranes (MMMs) for CO2/N2 separation. The 2D ZIF-8 fillers contributed to not only decreasing transport resistance due to highly porous nature but also strengthening CO2/ N2 diffusive separation of the MMMs due to keen molecular sieving through 4-membered windows, smaller than conventional 6-membered windows of ZIF-8. Aligned filler dispersion in out-of-plane direction was maintained up to 10 wt% filler loading and the MMM with 10 wt% filler loading showed optimal performance of CO2 permeability of -350 Barrer and CO2/N2 selectivity of -94, outperforming most of the reported 2D nanosheetbased MMMs in addition to exceeding the 2019 upper bound. To check commercial viability, thin film nanocomposite (TFN) membranes composed of a skin layer of -780 nm including 10 wt% filler loading were prepared. The TFN membranes exhibited CO2 permeance of -710 GPU and CO2/N2 selectivity of -77, which surpasses most of state-of-the-art polymeric thin film composite (TFC) and TFN membranes especially in terms of selectivity.

Pyrolysis of microalgal biomass is a potential strategy for biofuel production. In this work, the pyrolysis characteristics of microalgae, Tetraselmis sp., were systematically explored under isothermal and nonisothermal conditions. Analysis of nonisothermal decomposition of microalgae under nitrogen atmosphere at different heating rates (5, 10, 15, and 20 °C min−1) revealed that the conversion of microalgae was significantly affected by the heating rate and reached ~90% at approximately 500 °C. The mean activation energy for the pyrolysis of Tetraselmis sp. was calculated using model-free Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods. Microalgae pyrolysis in a micro-tubing reactor was performed at various temperatures (360-400 °C) and for different reaction times (0.5-3.0 min). The results indicated that the maximum yield of biocrude (49.5 wt%) was attained during pyrolysis at 400 °C for 2 min. It was established that the chemical composition of the biocrude was significantly influenced by the pyrolysis conditions. A quantitative model was used to evaluate the composition of carbohydrates, proteins, and lipids in the microalgae. This facilitated the determination of individual biochemical components in the pyrolytic products. Furthermore, the time- and temperature-dependent yields of the solid residue, biocrude, and gas were predicted, providing critical information for microalgal pyrolysis design, control, and performance.

Co-pyrolysis of biomass with plastics is an interesting research trend in improving both the yield and quality of oil products toward taking advantage of flexible material resources and sustainable fuel development. This study investigated the kinetic behaviors using thermogravimetric analysis and pyrolysis characterization for the co pyrolysis of biomass (bamboo and oak wood) with plastics (polypropylene [PP] and polystyrene [PS]) in a fixed-bed reactor. The kinetic triplet for feedstocks was determined using the isoconversional method, compensation effect, and master plot method. The addition of 20 wt% plastics into biomass decreased the activation energy, with the most distinct positive synergistic effect for the bamboo/PS blend. In addition, the effect of co-pyrolysis temperature and biomass/plastic ratio on pyrolysis characteristics was investigated. Through biomass pyrolysis and biomass/plastic co-pyrolysis, the positive changes in distributions and physical chemical properties of the products (i.e., char, oil, and gas) were observed using various analytical methods. Especially in the case of biomass/PS blends, the synergistic effect of co-pyrolysis was shown due to the difference in the actual and theoretical yields of the products. The liquid yields of the co-pyrolysis were 50.95, 50.17, 55.15, and 56.16 wt% for bamboo/PP, bamboo/PS, oak wood/PP, and oak wood/PS, respectively. The highest HHV of 28.22 MJ/kg was obtained for oil derived from the co-pyrolysis of bamboo/PS. Furthermore, co-pyrolysis chars have high HHVs in the range of 30.73-32.41 MJ/kg, suggesting that they can be used as solid fuels.

The pyrolysis characteristics and kinetics of Organosolv lignin from pine trees were investigated using iso-conventional, generalized master plot, model-based, and Frazer-Suzuki deconvolution methods. With these ap-proaches, the activation energies of Organosolv lignin pyrolysis were determined to be in the range of 70.11-385.58 kJ/mol. In addition, the activation energies of 3 pseudo-reactions were calculated to be 15.71, 204.49, and 32.76 kJ/mol, respectively, by the Frazer-Suzuki deconvolution method. The experimental data of Organosolv lignin pyrolysis were best fitted with the 4th power-law model (P4) with an absolute error of 3.24 %. Entropy (delta S-o), Gibbs free energy (delta G(o)), and enthalpy (delta Ho) were also calculated to understand the reaction pathways from a thermodynamic point of view. Based on the pyrolysis mechanisms proposed in this study, the reaction rate constants of different steps were determined. The primary reaction route was identified to be the pyrolysis of Organosolv lignin to liquid products such as bio-oils. Among the alkali and alkaline earth metals (AAEMs) tested, 2.0 wt% Mg showed the most effective on Organosolv lignin pyrolysis, decreasing the mean activation energy (E-a) from 181.67 to 156.55 kJ/mol in the range 0 <= X <= 0.85. The compositions of gaseous and liquid products formed by pyrolysis were analyzed using a micro-tubing reactor. CO, CO2, and CH4 were observed as the main gaseous products, while Organosolv lignin was primarily decomposed into phenol and guaiacol derivatives. The Organosolv lignin was also depolymerized into lower-molecular-weight (LMW) com-ponents during the pyrolysis process.

The catalytic hydrodeoxygenation (HDO) processes for upgrading pyrolysis bio-oils from wood pallet sawdust (WPS) were studied using activated carbon (AC) as a support of mono- (Co/AC and Fe/AC) and bi-metallic (Co-Fe/AC) catalysts. The effects of the reaction temperature and hydrogen pressure on products and high heating value (HHV) were systematically investigated. At 350 °C and 60 bar, 20 wt% Co/AC showed the highest liquid yield (70.46 wt%) along with HHV of 34.22 MJ/Kg. Among the tested bimetallic catalysts, comparable liquid yield (68.85 wt%) and HHV (34.16 MJ/kg) were achieved with 20 wt% 4Co-1Fe/AC catalyst. Methyl phenol derivatives were found to be the main component in upgraded bio-oil. The carbon number of the upgraded bio-oil was mainly distributed in C5–C11 fraction, especially with the C8 component (20.40 wt%). The catalysts were deactivated by the formation of carbonaceous compounds on the external surface, oxidation of metal species, and blocking of active sites on catalysts.

Developing highly active and stable hydrodeoxygenation (HDO) catalysts is an industrial challenge. In this work, γ-Al2O3 microspheres incorporating high levels of Mo catalyst (30 wt%; MoO3@Al2O3) were effectively and rapidly prepared by ultrasonic-assisted spray pyrolysis. The MoO3@Al2O3 microspheres were then decorated by a hydrophobic TiO2 layer to obtain core–shell-structured microspheres dubbed MoO3@Al2O3@TiO2. HDO experiments revealed that catalysis by reduced MoO3@Al2O3@TiO2 microspheres afforded ~96% palmitic acid (PA) conversion and ~ 67% hydrocarbon selectivity, surpassing the uncoated catalyst. Furthermore, the prepared TiO2-coated MoO3@Al2O3 microspheres retained excellent HDO catalytic activity under water-containing feed for 24 h. This study's results suggest that combining spray pyrolysis and coating with a TiO2 shell produces a synergetic effect that enhances the catalyst's activity and stability.

The kinetic parameters for the pyrolysis of biomass of the pitch pine (Rigida pine P. Mill) were examined by thermogravimetric analysis in the temperature range 25 degrees C to 700 degrees C, in which the main decomposition was occurred from 250 degrees C to 400 degrees C. Pyrolysis of pitch pine has been investigated in a bubbling fluidized bed reactor. In this system, silica sand and nitrogen were used as the fluidizing bed material and fluidizing medium, respectively. The experimental was systemically performed on different temperature, fluidized velocity, and particle size of biomass. The optimum temperature condition at which the bio-oil yields reached the highest value (65.5%) was 500 degrees C. In addition, the higher heating values of bio-oils from pitch pine biomass were reached in the range 22 MJ/kg to 24 MJ/kg. Moreover, this bio-oil had high content of useful chemicals including such as levoglucosan, furfural, and guaiacol. The large amount of C-5-C-11 (gasoline fraction) produced make the pyrolyzed oil originating from pitch pine trees a promising biofuel candidate. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

In the high-entropy alloy (HEA) community, many researchers have been trying to improve the strength of the CoCrFeMnNi HEA by generating a transformation-induced-plasticity (TRIP) effect and/or maximizing the solid solution hardening effect. Adding vanadium (V) to the CoCrFeMnNi HEAs could be an effective way to improve strength, because vanadium stabilizes the body-centered cubic (bcc) phase and its atomic size is larger than Co, Cr, Fe, Mn, and Ni. To design high strength V-added HEAs, we investigated the effect of vanadium on the critical resolved shear stress (CRSS) by utilizing an atomistic simulation, proposing an empirical equation to estimate the relative effect of alloying elements on the CRSS. For this, we first developed the Co-Cr-Fe-Mn-Ni-V hexanary interatomic potential by newly developing the Cr-V, Fe-V, and Mn-V binary interatomic potentials. As a result, two novel V-added HEAs were designed and the designed HEAs show higher strength than the previously developed non-equiatomic CoCrFeMnNi HEAs, as predicted from the empirical equation.

Gibberellins (GAs) are an important group of phytohormones associated with diverse growth and developmental processes, including cell elongation, seed germination, and secondary growth. Recent genomic and genetic analyses have advanced our knowledge of GA signaling pathways and related genes in model plant species. However, functional genomics analyses of GA signaling pathways in Panax ginseng, a perennial herb, have rarely been carried out, despite its well-known economical and medicinal importance. Here, we conducted functional characterization of GA receptors and investigated their physiological roles in the secondary growth of P. ginseng storage roots. We found that the physiological and genetic functions of P. ginseng gibberellin-insensitive dwarf1s (PgGID1s) have been evolutionarily conserved. Additionally, the essential domains and residues in the primary protein structure for interaction with active GAs and DELLA proteins are well-conserved. Overexpression of PgGID1s in Arabidopsis completely restored the GA deficient phenotype of the Arabidopsis gid1a gid1c (atgid1a/c) double mutant. Exogenous GA treatment greatly enhanced the secondary growth of tap roots; however, paclobutrazol (PCZ), a GA biosynthetic inhibitor, reduced root growth in P. ginseng. Transcriptome profiling of P. ginseng roots revealed that GA-induced root secondary growth is closely associated with cell wall biogenesis, the cell cycle, the jasmonic acid (JA) response, and nitrate assimilation, suggesting that a transcriptional network regulate root secondary growth in P. ginseng. These results provide novel insights into the mechanism controlling secondary root growth in P. ginseng.

Ni,Ti-co-doped MoO2 nanoparticles with excellent moisture stability and improved conductivity are synthesized via solvothermal cracking process for hole transporting material (HTM) in metal halide perovskite solar cells (MHP SCs). The Ni,Ti-doped MoO2 has similar oxidation state with pristine MoO2, but has better reduction stability than the MoO2 due to the weaker electronegativity of Ni and Ti than the Mo. Accordingly, the Ni,Ti-co-doped MoO2 HTM based MHP SC has 18.1% of power conversion efficiency at 1 sun (100 mW/cm(2)) condition. In addition, the un-encapsulated Ni,Ti-co-doped Mo0 2 HTM based MHP SC has 12-13% degradation after stability test under 85 degrees C/60% relative humidity for 20 days. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.